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Produtos (260)
CD74ACT163 - 4-Bit Sync Binary Counter 5V | Texas Instruments
The Texas Instruments CD74ACT163 is a 4-bit synchronous presettable binary counter with synchronous reset, fabricated in the advanced CMOS (ACT) logic family and housed in a 16-pin SOIC package. It operates from a 5V supply with TTL-voltage-compatible inputs, and features an internal carry look-ahead for high-speed counting designs plus a ripple carry output (RCO) for n-bit cascading. A synchronous binary counter is a sequential logic IC in which all flip-flops are clocked simultaneously by a common clock edge, so all output bits change in coincidence rather than rippling stage to stage. Within the logic IC hierarchy (counter -> sequential logic IC -> digital IC), synchronous counters eliminate the cumulative propagation delays of ripple (asynchronous) counters, enabling reliable high-speed counting and glitch-free decoded outputs. Key features include synchronous counting, synchronous parallel load via the active-low LOAD input for programmable counting, and synchronous reset (CLR) that clears all outputs on the next clock edge, eliminating the decoding spikes inherent in asynchronous clearing. The count-enable inputs (ENP, ENT) permit cascading and gated counting without external gating logic, and the RCO terminal supports direct n-bit cascading. The ACT technology combines CMOS low static power with TTL input thresholds at 5V operation, making the device directly interchangeable in TTL 74163 sockets. Positive-edge clocking and fully synchronous preset, count, and clear functions simplify timing analysis in multi-stage counter chains. Typical applications include frequency division, digital timers, event counting, address generation, industrial sequencing, and cascaded n-bit counters built by wiring RCO of one stage to ENT of the next. Design consideration: because reset and load are synchronous, hold CLR or LOAD low for at least one full clock period; for asynchronous-reset designs use the related CD74ACT161 instead. Decouple the 5V rail with 0.1uF close to the VCC pin. This page synthesizes distributor data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
CD74HC138 - 3-to-8 Line Decoder/Demux 2-6V | Texas Instruments
The Texas Instruments CD74HC138 is a high-speed silicon-gate CMOS 3-to-8 line decoder/demultiplexer with inverting outputs, supplied in a 16-pin package (PDIP, SOIC, and other variants), operating from a 2V to 6V supply with three binary select inputs and eight active-low outputs. According to the TI datasheet SCHS147J, the device is well suited to memory address decoding or data routing applications. A decoder/demultiplexer is a combinational logic device in the broader logic IC family (logic -> decoder -> demultiplexer -> data routing IC). Decoders convert binary-coded inputs into one-hot outputs, while the same circuit used with enables asserted acts as a demultiplexer routing data to one of eight output lines. The CD74HC138 belongs to TI's High Speed CMOS (HC) logic family, offering CMOS low power with LSTTL-comparable speed. Key features include three binary select inputs (A0, A1, A2) with full on-chip decoding, three enable inputs (two active-low, one active-high) supporting cascaded 4-to-16 or larger decoders without external gates, eight active-low outputs suited to memory chip-select (CS) and enable lines, low quiescent CMOS power consumption, and wide 2V to 6V supply operation typical of the HC family. Architecturally, the CD74HC138 uses high-speed silicon-gate CMOS construction with speeds comparable to low-power Schottky TTL logic. When used as a demultiplexer, the active-low enables serve as the data input while the select inputs route the data to the addressed output, eliminating external inverter gates. Typical applications include memory address decoding for SRAM/EPROM/Flash chip selects, I/O port expansion in microprocessor systems, data routing and demultiplexing, and address latching in embedded control systems. Its inverting outputs directly drive active-low memory CS/CE inputs without external inverters. Design tip: tie unused enable inputs to their inactive levels and keep select lines short; for 4-to-16 decoding, cascade two devices using one enable as the MSB select. Verify AC timing at your supply voltage and load. This page synthesizes distributor pricing, drop-in alternatives, cross-reference data, and practical design notes not found in the manufacturer datasheet.
CD74HC374 - Octal D Flip-Flop, 3-State, 2-6V | Texas Instruments
The Texas Instruments CD74HC374 is a high-speed CMOS logic octal positive-edge-triggered D-type flip-flop with 3-state outputs, housed in a 20-pin package (PDIP-20 (N), SOIC-20 (DW), or TSSOP-20 (PW)). It operates from a wide 2V to 6V supply and each output can drive up to 15 LSTTL loads, making it a robust bus-oriented storage element. An octal D-type flip-flop is a sequential logic IC containing eight independent D flip-flops that share a common clock and output-enable control. It belongs to the 74HC (High-speed CMOS) logic family, which combines LSTTL-compatible speed with the low static power consumption of CMOS technology, sitting within the broader hierarchy of digital logic ICs > flip-flops > edge-triggered registers. Key features include positive-edge-triggered data capture on the LOW-to-HIGH clock (CP) transition, 3-state outputs controlled by an active-low output enable (OE) that is independent of register operation, a typical propagation delay of 15 ns at 5V, and a maximum clock frequency of 30 MHz. The silicon-gate CMOS process provides high noise immunity and very low quiescent current compared with bipolar LSTTL equivalents. Architecturally, data present on the D inputs is stored on each rising clock edge, while OE=HIGH forces all Q outputs into a high-impedance state without disturbing the stored register contents. This enables bus multiplexing, shared data buses, and bidirectional data flow in microprocessor and memory systems. The device works in both 3.3V and 5V logic systems thanks to its wide supply range. Typical applications include microprocessor address and data latching, I/O port expansion, bus interfacing, register files, and synchronization stages in DSP and communication interfaces. Designers should keep the clock clean and glitch-free, control OE to avoid bus contention, and place 100 nF decoupling capacitors close to the VCC pin. According to TI datasheet SCHS183A, unused inputs must never be left floating. This page synthesizes distributor pricing, drop-in alternatives, pinout data, and practical design notes not found in the manufacturer datasheet alone.
CD74HC4511M96 - CMOS BCD-to-7-Segment Decoder/Driver SOIC-16 | TI
The Texas Instruments CD74HC4511M96 is a High Speed CMOS Logic BCD-to-7-Segment Latch/Decoder/Driver supplied in a 16-pin SOIC (D) package on tape and reel (M96 suffix). It operates over a 2 V to 6 V VCC range for the HC version, decodes four BCD address inputs (D0-D3) into seven segment outputs (a-g) plus ripple blanking, and integrates input latches, lamp-test (LT), and active-low blanking (BL) control inputs. Per the TI product page, the part delivers 10 mA source current per segment at 6 V on the HC variant, sufficient to directly drive common-cathode LED displays with external current-limiting resistors. A BCD-to-7-segment decoder is a logic IC that converts a 4-bit Binary Coded Decimal input (0-9) into the seven individual segment drive signals (a, b, c, d, e, f, g) needed to display a decimal digit on a 7-segment LED or LCD display. These devices sit in the logic IC hierarchy: decoder/driver -> display driver -> logic IC -> integrated circuit -> semiconductor. They are essential building blocks in numeric displays used in instrumentation, appliance panels, industrial counters, and embedded systems where a microcontroller must drive multi-digit readouts efficiently. Key features of the CD74HC4511M96 include input latches for BCD code storage, allowing data to be held stable while multiplexing multiple digits; lamp-test and blanking capability for testing all segments simultaneously and for PWM-based dimming; balanced propagation delays and transition times; and significant power reduction versus the original CD4000-series CMOS designs. The high-output sourcing capability (10 mA at 6 V) eliminates the need for external segment drivers in most LED display applications. The CD74HC4511M96 uses CMOS technology with CMOS-compatible inputs on the HC variant. Its 16-pin SOIC (D) small-outline surface-mount package measures approximately 9.9 mm x 3.9 mm with a 1.27 mm pin pitch, making it well-suited to compact PCB layouts. The integrated latch enables display multiplexing with no external storage, simplifying firmware and reducing microcontroller pin count when several digits share a data bus. Typical applications include digital panel meters, instrument counters, industrial control readouts, appliance displays (microwave ovens, washing machines), electronic scoreboards, point-of-sale terminals, and any embedded system that needs to display decimal digits on a 7-segment LED or LCD. Designers use it when they need a hardware decoder to offload display refresh from a microcontroller or when supporting multi-digit multiplexing without continuous MCU intervention. When designing with this device, add series resistors between each segment output and the LED anodes to limit current, or use a constant-current driver if brightness uniformity is critical. For multi-digit multiplexing, route BL through a PWM signal or high-frequency oscillator to achieve dimming and ghosting reduction. The LE (Latch Enable) input must be low for transparent operation and high to store the BCD code. The 'M96' suffix indicates tape-and-reel packaging for high-volume assembly. This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found on any single distributor listing, giving engineers a one-stop reference for selecting and using the CD74HC4511M96 in new designs and as a drop-in replacement.
CD74HCT165M96 - 8-Bit Parallel-In/Serial-Out Shift Register | TI
The Texas Instruments CD74HCT165M96 is an 8-bit parallel-in/serial-out shift register built on High-Speed CMOS (HCT) logic, housed in a 16-pin SOIC (D) package with a -55C to +125C operating temperature range. It provides complementary serial outputs (Q7 and Q7-bar) from the last stage, asynchronous parallel load via an active-low PL pin, and TTL-compatible inputs that interface directly with 5V CMOS or bipolar TTL logic rails. The wide operating temperature grade supports both commercial and military-grade designs in a single BOM line. What is a parallel-in/serial-out shift register? A shift register is a sequential logic block that stores and shifts multi-bit data along a chain of flip-flops on each clock edge. A parallel-in/serial-out (PISO) variant accepts 8 bits in parallel, then clocks them out one bit at a time over a serial line. Within the broader IC taxonomy, PISO registers sit under the Logic IC family -> Shift Registers -> PISO registers, and they are the building block of which microcontroller peripherals (UART, SPI) are typically constructed. PISO devices are used to reduce the I/O count on a host MCU by converting parallel button or sensor data into a single-wire serial stream. The CD74HCT165M96 features buffered inputs, complementary Q7/Q7-bar outputs, asynchronous parallel load, and a wide fanout of 10 LSTTL loads on standard outputs and 15 LSTTL loads on bus-driver outputs. The asynchronous load (active-low PL) lets the system load parallel data without waiting for a clock edge, which is critical when capturing fast events. Complementary outputs enable easy wire-OR or polarity-inversion without an external inverter. Architecturally, the CD74HCT165 uses HCT-CMOS silicon gates, which deliver CMOS-style low static power (typically microampere quiescent supply current) while presenting TTL-compatible input thresholds (VIL = 0.8 V, VIH = 2.0 V). The serial data path is implemented as 8 master-slave D flip-flops clocked by the rising edge of the CLK input, with the DS serial data input multiplexed through the PL-controlled input gate. The HCT family operates from a single 4.5 V to 5.5 V supply. Typical applications include scanning a matrix of front-panel push-button switches, multiplexing 8 lines of digital sensor data into a single microcontroller UART, expanding GPIO on low-pin-count MCUs, industrial control front-ends, and keyboard/mouse matrix scanners. In each case the part reduces host-side pin count and PCB routing complexity by converting parallel inputs to a single serial bit stream. When designing with this device, keep trace lengths short between parallel data sources and the D0-D7 inputs to minimize skew, and route the CLK and PL signals with a ground return to avoid transient capture errors. Power-supply decoupling of 0.1 uF next to VCC is recommended for noise-sensitive designs. This page synthesizes distributor stock, datasheet pinout, parametric drop-in alternatives, and PCB design notes not found in the manufacturer datasheet alone, giving procurement and engineering teams a single source for sourcing and replacement decisions.
CY14104V - IEEE 1149.1 Boundary-Scan Controller | Cypress
The Cypress (Infineon) CY14104V is a 1.8V-3.3V IEEE 1149.1 / IEEE 1149.7 boundary-scan (JTAG) controller and TAP controller companion IC, offered in a low-pin-count surface-mount package (per published part numbering convention). According to the manufacturer datasheet, this device provides compliant TAP (Test Access Port) signaling, programmable TCK frequencies, and integrated TAP domain support for both 4-wire JTAG and the 2-wire compact JTAG (cJTAG) variant standardized in IEEE 1149.7. A boundary-scan controller is a category of test and measurement IC that orchestrates boundary-scan testing of digital logic on a printed circuit board. It sits between an upstream test program generator (such as automatic test pattern generation tooling) and the JTAG scan chain on the target board. The device hierarchy is: IC -> TAP controller -> boundary-scan controller -> test & measurement semiconductor. Boundary-scan controllers reduce test-cost by eliminating the need for physical bed-of-nails fixtures and enable at-speed structural test of complex digital boards. Key features include wide supply voltage range, low standby current suitable for always-on test infrastructure, support for both standard JTAG (IEEE 1149.1) and compact JTAG (IEEE 1149.7), and integrated programmable frequency generation for TCK. The device is designed to interface cleanly with downstream JTAG-controlled devices including FPGAs, microcontrollers, and CPLDs that include boundary-scan cells per IEEE 1149.x. Typical applications include JTAG-driven production board testers, in-system programming (ISP) fixtures, debug and trace infrastructure for embedded targets, and field-test controllers where compact JTAG reduces pin count on test probe interfaces. When designing with this part, follow IEEE 1149.1 signal-integrity guidelines: keep TCK and TMS traces short, route them above a continuous ground reference, and add 10k-100k pull-ups on TMS and TDI to set a benign idle state at power-up. This page synthesizes distributor pricing, drop-in alternatives, and practical JTAG design notes not found in the manufacturer datasheet, providing a single-page reference for engineers evaluating the CY14104V for production test fixtures or development JTAG bridges.
DG408 - 8-Channel CMOS Analog Multiplexer 100Ω | Renesas
The Renesas DG408 is a single 8-channel CMOS analog multiplexer with 100 ohm maximum on-resistance, 15 pC maximum charge injection, and 1.25 mW maximum power consumption, housed in a 16-pin package (PDIP, SOIC, TSSOP options). An analog multiplexer is a signal-routing device that selects one of several analog inputs and connects it to a single output using an array of CMOS transmission gates controlled by digital address inputs. In the signal-chain hierarchy, the DG408 sits between sensors or signal sources and an ADC or amplifier, functioning as a digitally controlled switch matrix within the broader family of analog switches and multiplexers in data acquisition systems. Key features include guaranteed channel-to-channel on-resistance matching of 8 ohms max and on-resistance flatness of 9 ohms max, which preserve signal accuracy when switching between channels. The device offers TTL/CMOS-compatible digital inputs over the full operating temperature range, an ENABLE input for paralleling multiple muxes, and break-before-make switching to prevent momentary channel shorting. ESD protection exceeds 2000 V per datasheet specifications. Technically, the DG408 integrates eight CMOS analog switches, a TTL/CMOS-compatible 3-bit decoder, an internal voltage reference for logic thresholds, and an enable circuit on one monolithic die. Rail-to-rail analog signal handling allows the full supply range to be switched, and input leakage current is limited to 5 nA max at +85C, minimizing signal errors in high-impedance paths. Typical applications include high-speed data acquisition front ends, audio signal switching and routing, automatic test equipment (ATE) systems, and avionics, where its low leakage and fast, clean switching fit dense channel-scanning designs. When designing with the DG408, observe the break-before-make timing margin and keep the digital address lines clean, as slow edges can cause transient feedthrough during decoding. This page synthesizes drop-in alternative cross-references, application guidance, and design notes not consolidated in the manufacturer datasheet.
DG411 - Quad SPST CMOS Analog Switch, 35 Ohm | Analog Devices
The Analog Devices DG411 is a precision monolithic quad SPST CMOS analog switch featuring four independent single-pole single-throw switches with a maximum on-resistance of 35 ohm, a 44V maximum supply range, and TTL/CMOS-compatible digital inputs, housed in a 16-pin SOIC package. A quad SPST analog switch is an integrated circuit that contains four independent electronically controlled switches for passing or blocking analog signals. Within the signal-routing hierarchy, it sits above single SPST switches and below analog multiplexers, and is a foundational building block of the broader analog signal switching and power management IC families. The DG411 series conducts equally well in either direction, making it a true bilateral switch for AC and DC signals. Key features include a low on-resistance of 35 ohm maximum, on-resistance matching between switches of 3 ohm maximum, and guaranteed on-resistance flatness over the signal range of 4 ohm maximum, according to the manufacturer product page. The switches conduct equally well in either direction, and the digital inputs accept both TTL and CMOS logic levels. The DG411 series improvements are made possible by a high-voltage silicon-gate CMOS process. An epitaxial layer prevents the latch-up associated with older CMOS technologies. The 44V maximum voltage range permits controlling 40VP-P signals. Power supplies may be single-ended from 44V, or split from plus-minus 20V, giving designers flexibility in mixed-signal systems. Typical applications include audio signal routing, sample-and-hold circuits, data acquisition channel selection, precision test instrumentation, and communication system switching matrices. The four independent switches allow multiple signal paths to be controlled from separate logic lines without cross-channel interaction. When designing with the DG411, ensure logic drive levels meet the TTL/CMOS input thresholds, and verify that signal swing stays within the supply rails to avoid internal clamping. Note that the DG411 is normally-open; the DG412 (normally-closed) and DG413 (mixed) share the same pinout for polarity changes without PCB rework. This page synthesizes distributor pricing, drop-in alternatives across multiple manufacturers, and practical design notes not found in the manufacturer datasheet.
DG412DJ-E3 - Quad SPST CMOS Analog Switch 35Ohm | Vishay
The Vishay Siliconix DG412DJ-E3 is a precision monolithic quad SPST CMOS analog switch IC with a maximum on-resistance of 35 ohm, four independent 1:1 switch channels, and supply operation over the ±13.5V to ±16.5V range, housed in a 16-pin PDIP (DIP-16) through-hole package. An analog switch is a semiconductor device that routes or blocks analog signal paths under digital control, acting like a relay but with far higher speed, lower power, and smaller size. Within the signal-routing hierarchy, the analog switch sits below analog multiplexers (which select among many channels) and above transmission gates, forming a fundamental building block of the broader analog front-end and signal-conditioning IC family. The DG412 provides four normally-closed SPST switches, while its DG411 and DG413 family siblings provide normally-open and mixed configurations. Key features include low on-resistance (35 ohm max), extremely low power consumption of 0.35 uW, TTL and CMOS compatible digital inputs, and fast switching of precision analog signals. The monolithic CMOS construction ensures matched switch characteristics and low charge injection, preserving signal integrity in precision measurement paths. Architecturally, each channel is a CMOS transmission-gate switch driven by a level-shifting logic interface, allowing digital control signals referenced to logic supplies to switch analog signals riding on dual ±15V rails. This is the classic precision switch topology inherited from the DG211/DG212 generations; per the manufacturer documentation, the DG411 series is a drop-in replacement for DG211/DG212 devices. Typical applications include sample-and-hold circuits, precision integrators and peak detectors, audio and instrumentation signal routing, and test-equipment channel switching, where quad SPST control with low error switching is required. A key design consideration: with 35 ohm on-resistance, ensure downstream load impedances remain high (100x switch resistance or more) to limit gain error, and always observe the ±13.5V to ±16.5V supply range with appropriate supply decoupling. This page synthesizes verified distributor listings, cross-reference data, drop-in alternative analysis, and practical design notes not found in the manufacturer datasheet.
DG413 - Quad SPST CMOS Analog Switch, 44V | Analog Devices
The Analog Devices DG413 is a monolithic quad SPST CMOS analog switch with four independent single-pole single-throw switches (two normally-closed and two normally-open), a 35 ohm maximum on-resistance, sub-150 ns switching times, and a 44 V maximum supply rating in a 16-pin SOIC package. An analog switch is a semiconductor device that routes or blocks analog signal paths under digital control. Within the signal-routing hierarchy, the analog switch sits below analog multiplexers and above discrete transistor switches, forming a core building block of signal conditioning and power management systems. The DG411/DG412/DG413 family from Analog Devices (originally Maxim Integrated, also second-sourced by Renesas/Intersil and Vishay Siliconix) is an industry-standard pinout. Key features include TTL- and CMOS-compatible digital inputs, operation from a single +10V to +30V supply or bipolar ±4.5V to ±20V supplies, and a 44V silicon-gate process with an epitaxial layer that prevents the latch-up associated with older CMOS technologies. The improved family offers lower on-resistance (35 ohm vs. older DG211/DG212 parts) and faster switching (tON 175 ns class, max 150 ns; tOFF max 100 ns per Analog Devices). Technically, the DG413 uses a high-voltage silicon-gate CMOS process enabling 40VP-P signal handling and reduced charge injection versus predecessors. It is a drop-in replacement for the popular DG211/DG212 series. Typical applications include audio signal routing, sample-and-hold circuits, precision test instrumentation, and industrial signal multiplexing, where low on-resistance and fast switching improve signal fidelity. Design tip: keep the analog signal within the supply rails and decouple V+ and V- pins with 0.1 uF ceramics to preserve charge-injection performance. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
DG413DY-E3 - Quad SPST 35 Ohm Analog Switch | Vishay Siliconix
The Vishay Siliconix DG413DY-E3 is a precision monolithic quad SPST CMOS analog switch providing four independent single-pole single-throw channels with 35 ohm typical on-resistance, 110 ns switching time, and bidirectional analog signal handling up to 15 V, housed in a 16-pin SOIC package. The -E3 suffix denotes lead-free, RoHS-compliant (Directive 2002/95/EC) construction with tin-plated matte finish. A CMOS analog switch is a semiconductor device that routes or gates analog signals using MOSFET transmission gates controlled by TTL/CMOS-compatible logic inputs. Within the signal-chain hierarchy, analog switches sit between logic ICs and analog multiplexers, serving as building blocks for signal routing, sample-and-hold circuits, and channel selection in data acquisition systems. Key features include ultra-low power dissipation of 0.35 uW, making the DG413DY-E3 suitable for battery-powered and portable instrumentation; a 44 V maximum supply rating with flexible dual-supply operation (V+ to V-); fast switching with typical turn-on time of 110 ns; and TTL/CMOS-compatible logic inputs. The switches conduct equally well in either direction, and the DG413 variant offers normally-open (NO) logic polarity for all four channels. The device is built on a monolithic CMOS process that combines a high-voltage CMOS driver stage with low-threshold MOSFET switches, achieving low charge injection and glitch-free switching transitions. Compared with the older DG211/DG212 series it replaces, the DG411/DG412/DG413 family offers lower on-resistance and faster switching in the same footprint. Typical applications include precision signal routing in data acquisition systems, audio signal switching, battery-powered test equipment, industrial control channel selection, and communication-system switch matrices, where low power and glitch-free performance are priorities. When designing with the DG413DY-E3, keep the analog signal range within V+ and V- supply rails to avoid latch-up, and use short, low-capacitance traces on the source/drain lines to preserve switching speed and minimize crosstalk. This page synthesizes distributor pricing, drop-in alternatives, design notes, and application guidance not found in the manufacturer datasheet alone.
DG441 - Quad SPST NC CMOS Analog Switch | Analog Devices
The Analog Devices DG441 is a monolithic quad SPST (normally closed) CMOS analog switch containing four independent single-pole single-throw switches with TTL and CMOS compatible digital inputs and an internal voltage reference for logic thresholds, housed in 16-pin DIP and SOIC packages. It is specified as a drop-in replacement for the popular DG201A and DG202 series switch sockets. An analog switch is an electronically controlled relay built on CMOS transmission-gate technology: a logic-level control input opens or closes a bidirectional signal path that conducts equally well in either direction. Within the signal-routing hierarchy, analog switches sit between mechanical relays and fully integrated multiplexers, offering microsecond-or-faster switching, no moving parts, and very low power dissipation in power management and signal-chain front ends. Key features of the redesigned DG441 include guaranteed on-resistance matching of 4 ohm max between the four switches, guaranteed on-resistance flatness over the analog signal range of 9 ohm max, and low, minimized charge injection at the drain terminal - a parameter that matters directly in sample-and-hold circuits. Typical on-resistance is approximately 45 to 50 ohm with typical turn-on time around 150 ns per the Vishay and Renesas datasheets. Technically, each switch uses an NMOS/PMOS pair driven by an internal level shifter referenced to the VL logic-threshold pin, allowing 5V TTL or 15V CMOS control logic to command analog signal swings as large as the VDD-to-VSS supply span, typically plus/minus 15V operation from plus/minus 20V maximum rails. Typical applications include data acquisition channel multiplexing, automatic test equipment (ATE) matrix switching, communication systems, and medical instrumentation front ends - anywhere that a legacy DG201A/DG202 socket needs a modernized, better-matched switch. Design consideration: keep the analog signal within the supply rails at all times, even at power-up, or internal protection diodes will conduct and can latch the device. This page synthesizes distributor pricing, verified drop-in alternatives (DG442, ADG441, DG441B, DG444), and practical design notes not found in any single manufacturer datasheet.
DM74LS138N - 3-to-8 Line Decoder/Demultiplexer, LS-TTL, 16-PDIP | onsemi
The onsemi (formerly Fairchild) DM74LS138N is a 3-to-8 line decoder/demultiplexer built on Schottky-clamped Low-power Schottky (LS) TTL technology, packaged in a 16-pin PDIP through-hole format. The device accepts three binary-weighted address inputs (A, B, C) and provides eight active-LOW mutually exclusive outputs (Y0-Y7), along with three enable inputs (G1, G2A, G2B) that allow cascading or address expansion. According to the manufacturer datasheet, it is designed for high-performance memory-decoding and data-routing applications requiring very short propagation delay times. A decoder/demultiplexer is a combinational logic IC that translates a binary address on its inputs into a single selected output line. In its canonical role, the '138' family member accepts 3 address bits and activates exactly one of 8 outputs, which is why it is commonly referred to as a 1-of-8 decoder. It belongs to the broader hierarchy: decoder/demultiplexer -> combinational logic -> logic IC -> digital IC -> integrated circuit -> semiconductor. Common synonyms include '3-line to 8-line decoder', 'binary-to-octal decoder', and '1-of-8 demultiplexer'. The device also functions as a demultiplexer when the enable inputs are used to pass an input signal through to one of the eight outputs based on the address. Key specifications include three address inputs with active-LOW enable gating, very low propagation delay (typical LS-TTL class ~10-20 ns), low-power Schottky construction for reduced power consumption versus standard 74xx TTL, and TTL-compatible input/output logic levels. The device is pin-compatible with the broader 74LS138, SN74LS138, and 74HC138 families, although power supply and logic levels differ between LS and HC variants. Architecturally, the DM74LS138N uses Schottky-diode-clamped transistor logic (LS-TTL) to achieve the speed of standard TTL with about one-third the power consumption. The internal NAND gate matrix decodes the three-bit address into one of eight lines, while the three enable inputs (one active-high, two active-low) implement a built-in 3-input AND gate whose output gates the decoded result. This design eliminates the need for external gating when multiple decoders are cascaded to expand the address space. Typical applications include memory chip-select decoding in 8080/8085/Z80 microprocessor systems, address demultiplexing in 8-bit and 16-bit bus architectures, I/O port selection, waveform generation via cascaded decoders, and general-purpose binary-to-octal decoding. The three enable inputs make it particularly easy to build larger decoders (5-to-32, 6-to-64) by combining two or four devices. When designing with the DM74LS138N, ensure that the VCC supply is regulated at 5V ±5% and that unused enable inputs are tied to their active logic level (G1 high, G2A/G2B low) to prevent false decoding. Because this is a through-hole PDIP part, it is most appropriate for breadboard prototyping, legacy system maintenance, and educational designs; for new high-volume designs consider surface-mount 74HC138 or 74HCT138 equivalents. This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
DS28E25+ - SHA-256 1-Wire Authenticator, 4Kb EEPROM, TO-92 | Analog Devices
The Analog Devices DS28E25+ (formerly Maxim Integrated) is a DeepCover secure authenticator that combines a hardware SHA-256 accelerator, a 4096-bit user EEPROM, and a unique 64-bit ROM ID on a single 1-Wire bus in a TO-92 (3-pin) through-hole package. It operates from 2.97 V to 3.63 V on the data/parasite-power line and communicates over the single-contact 1-Wire interface at standard and overdrive speeds, providing strong cryptographic authentication for anti-counterfeiting and peripheral identification. A secure authenticator is a specialized IC category within the broader semiconductor security hierarchy: secure authenticator -> cryptography IC -> security IC -> interface/specialized IC. DeepCover is Analog Devices' portfolio of security ICs that embed cryptographic primitives, physically secure key storage, and active die-level shielding to protect against invasive and non-invasive attacks, addressing system-on-board (SoB) and peripheral-authentication use cases where a software-only root-of-trust is insufficient. Key features include hardware SHA-256 computation over user memory, a 64-bit secret, a host random challenge, and the 64-bit ROM ID; on-chip 4 Kb (512-byte) user EEPROM organized in 32 pages of 16 bytes; 1-Wire overdrive communication up to 76.9 kbps; a unique factory-lasered 64-bit registration number; and write-only/read-only protection modes per page. The TO-92 package is chosen for cable-mounted peripherals (medical sensors, printer cartridges, e-meter modules) where the authenticator is soldered or clipped onto a flying lead and survives harsh mechanical environments. Architecturally, the DS28E25 isolates the secret in a protected memory block that participates in the SHA-256 hash but is never exposed on the bus. Host-side verification reads the public EEPROM, generates a random challenge, computes SHA-256 in firmware, and compares the result with the device-returned MAC - a strong two-factor scheme where knowledge of the secret alone cannot impersonate the device without the physical silicon. Typical applications include medical sensor authentication (single-use disposable probes), printer and consumable cartridge identification, industrial control module anti-counterfeiting, e-meter tamper detection, and IoT node provisioning. In each case the DS28E25+ provides a hardware root-of-trust that is impractical to clone. When designing with this part, place a strong pull-up (typically 4.7 kohm to VPUP, the 1-Wire pull-up rail) on the data line, observe the VPUP range of 2.97 V to 3.63 V during reads and EEPROM writes, and verify parasitic-power budgeting during long EEPROM-programming intervals where current can reach several milliamps. Decoupling on the VPUP rail with a 0.01 uF to 0.1 uF ceramic capacitor close to the device improves write reliability. This page synthesizes distributor pricing, drop-in alternatives from the same product family and competitor equivalents, and practical design notes not found in the manufacturer datasheet.
EPM5192GM-1/883B - 192-Cell UV PLD, 55ns, CPGA-84 Military | Intel
The Intel / Altera EPM5192GM-1/883B is a high-density, high-speed UV-erasable programmable logic device (PLD) from the MAX 5000 family, delivering 192 macrocells in an 84-pin ceramic PGA (CPGA-84, windowed) package. It features a 55ns propagation delay, CMOS technology, and is processed to MIL-STD-883B military grade, making it suitable for extended-temperature and defense/aerospace applications. A Programmable Logic Device (PLD) is a digital IC whose logic function is defined after manufacturing, allowing engineers to implement custom glue logic, state machines, and bus interfacing without fabricating a full ASIC. The MAX 5000 family sits in Altera's classic PLD hierarchy between the smaller MAX 3000 (EPM3xxx) and the larger MAX 7000 (EPM7xxx), targeting high-density designs that exceed simple SPLD (PAL/GAL) capacity. This product type hierarchy runs PLD -> programmable logic -> logic IC -> integrated circuit -> semiconductor, giving the part broad coverage in digital logic taxonomies. Key features of the EPM5192GM-1/883B include 192 logic macrocells, a maximum pin-to-pin propagation delay of 55ns, and an erasable windowed ceramic package for prototype and reprogrammable production use. The /883B suffix indicates full MIL-STD-883B processing for high-reliability military and aerospace programs, with the operating temperature range extending across -55C to +125C. The CPGA-84 package provides robust mechanical and thermal performance for harsh-environment systems. Technically, the device uses Altera's classic EEPROM/UV-CMOS MAX architecture with a programmable AND/OR array and dedicated macrocell flip-flops. The 55ns tPD places it in the medium-speed tier suitable for control logic, bus interfacing, and glue logic rather than high-speed datapath applications. The 192 macrocells and high I/O count make it one of the larger classic PLDs of its era. Typical applications include military and aerospace digital control systems, industrial control logic, legacy avionics and radar signal processing interface logic, defense telemetry equipment, and MIL-spec replacement of obsolete 54xx TTL logic arrays. Engineers use it where high reliability, -55C to +125C operation, and high-density PLD logic are required. Design considerations include the UV-erase window requiring a quartz-windowed package for reprogramming, which is slower than EEPROM-based modern PLDs. Designers must budget for the 55ns propagation delay when interfacing to faster buses. Use Altera's MAX+PLUS II development toolchain for design entry, fitting, and programming. This page synthesizes distributor stock data, same-family Altera drop-in alternatives, and design guidance not consolidated in the original datasheet, giving procurement and engineering teams a single reference.
GTL2012DP,118 - 2-Bit LVTTL-to-GTL Transceiver | NXP Semiconductors
The NXP Semiconductors GTL2012DP,118 is a 2-bit bidirectional LVTTL-to-GTL translating transceiver designed for 3.3 V system interfacing with a GTL-, GTL, or GTL+ bus, housed in an 8-pin TSSOP (SOT765-1 / VSSOP-8, MO-187) surface-mount package with an operating temperature range of -40 C to +85 C. A GTL (Gunning Transceiver Logic) translator is a mixed-signal level-shifting device that bridges a low-swing backplane bus such as GTL- (approximately 0.4 V to 1.2 V swing) with a standard logic rail such as 3.3 V LVTTL. Within the signal-chain hierarchy, the GTL2012 belongs to the logic IC family, specifically the voltage-level translator / bus transceiver category, sitting between a processor or memory controller and a GTL backplane. Key features of the GTL2012 include a direction (DIR) control pin that configures the device either as a GTL-to-LVTTL sampling receiver or as an LVTTL-to-GTL driver, LVTTL-side inputs tolerant up to 5.5 V for direct connection to TTL or 5 V CMOS logic, and a compact 2-channel width suited to narrow point-to-point links. According to the NXP datasheet, the supply range is 3 V to 3.6 V with a maximum supply current of 10 mA. Technically, the two channels translate open-drain GTL signals referenced to a GTL termination rail into full-swing LVTTL levels, and vice versa. The open-drain GTL outputs require pull-up resistors to the GTL reference supply, a typical arrangement in Gunning Transceiver Logic backplanes. Because the LVTTL inputs alone are 5.5 V tolerant, legacy 5 V TTL signals can be received without additional protection circuitry. Typical applications include processor-to-backplane bus interfacing in telecom and industrial systems, memory subsystem translation where a GTL bus meets a 3.3 V controller, and mixed-voltage board-level bridges in legacy equipment maintenance. Design consideration: always provide adequate GTL pull-up termination and verify that the DIR pin is driven to a valid logic level before bus traffic begins, since an undefined direction state can cause bus contention. This page adds value beyond the manufacturer datasheet by synthesizing distributor sourcing information, drop-in alternative analysis, FAQ coverage of replacement intent, and practical design notes for the GTL2012DP,118.
GTL2018PW,118 - 8-bit LVTTL to GTL Transceiver | NXP | TSSOP-24
The NXP Semiconductors GTL2018PW,118 is an 8-bit bidirectional voltage-translating transceiver designed to interface a 3.3 V LVTTL/TTL system bus with a GTL-, GTL, or GTL+ backplane bus, housed in a 24-pin TSSOP (SOT355-1, MO-153) surface-mount package. A GTL (Gunning Transceiver Logic) transceiver is a mixed-signal level translator that bridges low-swing, open-drain backplane signaling (approximately 1 V or lower swing, terminated to a GTL reference) with standard CMOS/LVTTL logic rails. Level translators sit in the interface-logic layer of the signal-chain hierarchy, between bus transceivers and voltage supervisors, and are essential wherever processor front-side buses, memory modules, or backplanes use GTL signaling while system logic runs at 3.3 V or 5 V. Key features include 8 bidirectional translation channels, a direction (DIR) pin that selects GTL-to-LVTTL sampling-receiver mode or LVTTL-to-GTL driving mode, and LVTTL-side inputs tolerant up to 5.5 V, allowing direct connection to TTL or 5 V CMOS sources without external protection. Supply operation is centered on a 3.3 V LVTTL rail, and the operating temperature range spans -40 C to +85 C, qualifying the device for industrial-grade environments. Technically, the GTL2018 uses an open-drain GTL output stage referenced to a GTL termination voltage, so the GTL bus requires external pull-up resistors to the GTL reference level. The sampling-receiver architecture captures GTL bus state and re-drives it as clean LVTTL, while the DIR pin flips the entire port in one control line - simplifying bus arbitration and turnaround timing on multipoint buses. Typical applications include server and telecom backplane interfaces, memory-module (GTL DIMM) translation, processor-to-peripheral bus bridging, and industrial control systems where legacy 5 V TTL logic must communicate with GTL-based CPU buses. Design consideration: budget for the GTL bus pull-up resistors and their current draw, and verify that 3.3 V LVTTL timing margins still hold with the translator propagation delay inserted into the bus path. This page adds value beyond the manufacturer datasheet by consolidating drop-in alternatives, engineering design notes, and a comparison table in one place.
GTL2018PW-Q900118 - 8-Bit LVTTL to GTL Transceiver | NXP
The NXP GTL2018PW-Q900118 is an 8-bit bidirectional LVTTL-to-GTL translating transceiver with a 3.3 V LVTTL supply, GTL/GTL-/GTL+ bus interface, and 24-pin TSSOP (SOT355-1) package, qualified over an operating temperature range of -40 C to +85 C. A translating transceiver is a mixed-signal level-shifter IC that moves digital signals between two logic families operating at different voltage levels. Within the signal-chain hierarchy, the GTL2018 belongs to the voltage translator family, under logic ICs, and mixed-signal interface semiconductors. GTL (Gunning Transceiver Logic) is a low-swing backplane bus standard historically used in computer motherboards and peripheral interconnects, where the LVTTL-side controller cannot directly drive the low-swing GTL bus. Key features include an octal (8-channel) bidirectional architecture controlled by a single DIR (direction) pin, allowing the part to operate either as a GTL-to-LVTTL sampling receiver or as an LVTTL-to-GTL driver. The LVTTL-side inputs are 5.5 V tolerant, permitting direct connection to TTL or 5 V CMOS logic without external clamping. The Q900 suffix denotes an automotive-grade qualification variant with extended quality screening. Technically, the device implements open-drain GTL outputs with a reference voltage (GTL ref) defining the bus switching threshold, translating between the 3.3 V LVTTL domain and the low-swing GTL domain. Because translation is bidirectional per the DIR control, one 24-pin package replaces multiple discrete transistor level-shift stages, reducing BOM count and board area on bus-heavy designs. Typical applications include legacy computer and server backplane GTL buses, telecommunications line cards, industrial control interfaces bridging 3.3 V or 5 V TTL controllers to GTL peripherals, and automotive ECU bus interfaces for the Q900-qualified variant. Design consideration: the GTL bus requires proper reference-voltage generation and termination resistors on the GTL side; verify the termination network against the bus loading before layout. This page synthesizes distributor availability data, the manufacturer product page, and drop-in alternative analysis not consolidated in the standard datasheet.
GTL2034PW - 4-Bit GTL to GTL Bus Buffer | NXP | TSSOP-24
The NXP Semiconductors GTL2034PW is a 4-bit GTL/GTL+/GTL bus buffer with open-drain GTL outputs, a 3.3 V LVTTL-side supply, and a 24-pin TSSOP (SOT355-1, MO-153) package rated from -40C to +85C. A GTL (Gunning Transceiver Logic) buffer is a specialized level-shifting and line-driving device in the logic IC family that interfaces a low-voltage LVTTL system side with a GTL/GTL+ backplane or memory bus. GTL buses use open-drain outputs with pull-up resistors to a terminated reference voltage (VTT), making buffer selection critical for signal integrity in multi-drop, backplane, and memory-interconnect topologies. Key features include true 4-bit GTL-to-GTL buffering, GTL inputs and outputs that operate up to 3.6 V for use in higher-voltage open-drain output applications, and a DIR direction pin that configures the device either as a GTL-to-LVTTL sampling receiver or as an LVTTL-to-GTL driver. The LVTTL side operates from a single 3.3 V supply, simplifying integration with standard logic rails. Architecturally, the GTL2034 combines sampling receiver circuitry on the LVTTL side with open-drain GTL drivers on the bus side. The open-drain outputs require external pull-up resistors to VTT, and the 3.6 V GTL I/O tolerance gives designers margin when the pull-up rail sits above the nominal 3.3 V level. Because only four bits are buffered per device, multiple GTL2034 devices can be deployed incrementally where a wide 20-bit buffer such as the GTL2000 family member would be oversized. Typical applications include memory-bus buffering in telecom and datacom line cards, GTL+ backplane interfaces in industrial control systems, and level translation between 3.3 V LVTTL processors and legacy GTL-based peripherals. For reliable operation, size the VTT pull-up resistors to achieve the specified GTL output low level at the expected bus load, and tie the DIR pin to a defined level rather than leaving it floating. Decouple the 3.3 V supply with 0.1 uF ceramics placed close to the package pins. This page synthesizes distributor listings, the official NXP datasheet link, and drop-in replacement guidance (including the NXP-recommended GTL2034PWZ) not consolidated in the manufacturer datasheet alone.
GTL2034PW,112 - 4-Bit GTL to GTL Buffer TSSOP-14 | NXP
The NXP Semiconductors GTL2034PW,112 is a 4-bit GTL to GTL non-inverting bus buffer with open-drain outputs, operating from a 3.3 V supply with I/O tolerance up to 3.6 V, housed in a 14-pin TSSOP (SOT402) surface-mount package. It buffers four GTL, GTL+ or GTL/ANSI bus signals at high speed while providing electrical isolation between heavily loaded backplane segments and the local driver circuitry. A GTL (Gunning Transceiver Logic) buffer is a specialized member of the voltage translator and line driver family within the logic IC hierarchy. GTL uses a low-swing, open-drain, backplane-oriented signaling scheme in which a termination to a reference voltage defines the logic levels; buffers such as the GTL2034 regenerate the weak, heavily capacitive signals found on long bus runs without adding logic function, restoring signal integrity between a processor board and a backplane or between isolated bus segments. Key features of the GTL2034 include its 4-bit (4 element, 1 bit per element) non-inverting buffer configuration, true open-drain outputs that support wired-OR and live-insertion style GTL topologies, and I/O structures that operate up to 3.6 V so the device can be used in higher-voltage open-drain output applications. The buffer architecture minimizes propagation delay, preserving setup and hold margins in high-speed bus systems. Technically, the GTL2034 sits between the input GTL node and the output GTL node as a re-driver: the input stage senses the low-swing GTL logic level relative to the GTL reference, and the output stage sinks current through the external pull-up termination to regenerate a clean edge. Because the outputs are open-drain, the output high level is set entirely by the external termination rail, which is characteristic of GTL, GTL+ and BTL-family signaling. The 3.3 V supply powers only the internal sensing and drive circuitry, keeping static power low while supporting fast edge rates. Typical applications include processor-to-backplane GTL bus buffering in telecommunications and networking equipment, memory subsystem interconnect in industrial controllers, and any distributed GTL/GTL+ bus where fan-out, bus capacitance or segment length would otherwise violate timing or signal-integrity budgets. Per NXP product information, the device supports data rates up to 250 MHz in these bus-buffering roles. Design consideration: because the outputs are open-drain, correct termination resistor selection to the GTL termination rail is critical - the termination value sets both the output high level and the pull-up rise time, and must be chosen against bus capacitance and required edge rate. This page synthesizes distributor listings, the official NXP datasheet link, drop-in replacement guidance (NXP designates the GTL2034PWZ as the drop-in replacement for discontinued packing variants), and practical design notes not consolidated in the datasheet alone.
GTL2034PW,118 - 4-Bit GTL Bus Buffer Open-Drain | NXP
The NXP Semiconductors GTL2034PW,118 is a 4-bit GTL-/GTL/GTL+ bus buffer with non-inverting open-drain outputs, housed in a 14-pin TSSOP (PW) surface-mount package rated for -40C to +85C operation. A GTL (Gunning Transceiver Logic) buffer is a specialized line driver used in voltage-level translation and bus-repeater applications. Within the power-management and logic hierarchy, it sits between generic logic ICs and dedicated voltage level translators: it isolates and re-drives heavily loaded backplanes by regenerating signal edges while the open-drain architecture lets the termination voltage define the logic swing. GTL and GTL+ are open-drain, terminated-low bus standards historically used for processor-to-memory backplanes in telecom, industrial, and networking equipment. Key features of the GTL2034 include 4 bits of non-inverting buffering (one bit per element), open-drain GTL outputs compatible with GTL, GTL-, and GTL+ signaling, and GTL inputs and outputs that operate up to 3.6 V, allowing the device to be used in higher-voltage open-drain output applications. The buffered architecture minimizes propagation delay degradation across long, heavily capacitive backplane runs compared with passive repeaters. Architecturally, the GTL2034 regenerates each input edge before driving the open-drain pull-down, which isolates bus capacitance from the source and preserves signal integrity on long terminated lines. Because outputs are open-drain, the pull-up voltage is independent of the supply, giving designers flexibility in mixed-voltage systems up to 3.6 V on the GTL side. Typical applications include telecom line cards, industrial backplane bus repeaters, processor-memory interface level shifting, and legacy server infrastructure maintenance. The 4-bit width suits address and control lines where a full 14-bit translator is oversized. Design consideration: open-drain outputs require external pull-up resistors sized against the bus termination network, and supply decoupling of 0.1 uF per device is recommended. Verify output sink current against the total bus load. Important lifecycle note: NXP has discontinued the GTL2034PW,118 (discontinuation notice dated 2021-11-03), and the manufacturer designates GTL2034PWZ as its drop-in replacement. This page synthesizes distributor pricing, lifecycle status, and replacement guidance not found in a single manufacturer datasheet.
HCF4093BE - Quad 2-Input NAND Schmitt Trigger | STMicroelectronics
The STMicroelectronics HCF4093BE is a CMOS quad 2-input NAND gate with Schmitt-trigger inputs, supplied in a 14-pin PDIP through-hole package. Each of the four independent gates performs the NAND function while exhibiting Schmitt-trigger hysteresis on both inputs, allowing slow or noisy edges to be cleaned into sharp, jitter-free logic transitions. The Schmitt trigger is a comparator-style input stage with two distinct switching thresholds: a higher positive-going threshold (VP) and a lower negative-going threshold (VN). The difference between them (VH = VP - VN) is defined as the hysteresis voltage. This built-in hysteresis makes the part ideal for conditioning slow analog or mechanical signals (RC oscillators, switch debouncing, sensor pulses) directly into clean logic levels without external comparators. The HCF4093 belongs to the 4000-series CMOS logic family, characterized by wide supply operation from 3 V to 18 V, low quiescent power consumption, and high noise immunity. Its four gates share common VDD and VSS pins. Each input is a standard CMOS inverter-style stage feeding a NAND tree, and outputs are buffered totem-pole drivers capable of sourcing/sinking typical 4000-series currents. As a CMOS part, all inputs include ESD-protection networks and should not be left floating. Typical applications include waveform and pulse shaping, monostable and astable multivibrators, line receivers for noisy environments, simple RC and crystal oscillators, and debounce circuits for mechanical switches. Hysteresis prevents multiple triggering on bouncing or slowly rising edges, eliminating the need for external Schmitt-trigger comparator stages. When designing with this device, observe standard CMOS handling: tie unused inputs to VDD or VSS (never leave them open) and place a 0.1 uF decoupling capacitor as close as possible to the VDD pin. Output drive capability is moderate (a few mA), so check fan-out when driving multiple loads or long traces.
HCS361-I/P - KEELOQ Code Hopping Encoder, 8-PDIP | Microchip
The Microchip Technology HCS361-I/P is a code hopping encoder that pairs a 28-/32-bit programmable serial number with a 64-bit programmable encryption key to produce a 67-bit transmission frame (32-bit hopping code + 35-bit fixed code) for unidirectional Remote Keyless Entry (RKE) and access-control systems. Packaged in an 8-pin PDIP through-hole outline and rated for operation from 2.0 V to 6.6 V (per Microchip datasheet) or 3.0 V to 6.9 V (per some distributor listings), it ships as a -40 °C to +85 °C industrial-grade part with the “-I” temperature suffix and the “/P” PDIP package suffix. A code hopping encoder is a security-focused transmitter IC that transmits a different encrypted code on every button press, defeating simple replay attacks. It belongs to the broader category of encoders/decoders/multiplexers (logic ICs), and within Microchip's portfolio it is a member of the KEELOQ family — a hierarchy that runs encoder -> KEELOQ hopping encoder -> security transmitter IC -> logic IC -> integrated circuit. The HCS361 sits between the lower-cost HCS300/HCS301 and newer HCS362/HCS365 devices, balancing small package outline, low BOM cost, and patented hopping-code security. Key features include 28/32-bit serial number programming, 64-bit encryption key storage in EEPROM, unique 67-bit transmission per button event, three button inputs (S0/S1/S2), a 4-word (S0..S3 with PWM) option (per family datasheet), low standby current for battery-powered fobs, automatic code-word synchronization, and Microchip's patented KEELOQ learning algorithm so a paired receiver only needs to remember the last transmitted code. HCS361-I/P is the industrial temperature (-40 °C to +85 °C) variant in the through-hole PDIP-8 footprint. The device uses Microchip's KEELOQ nonlinear block-cipher algorithm with a 64-bit manufacturer key and a 16/20-bit discriminator. On every button press the encoder generates a fresh 32-bit hopping code by combining the counter value, the button bitmap, and the encrypted discriminator; the receiver validates the rolling counter and decrypts the discriminator before accepting the transmission, providing strong replay-attack immunity for garage-door openers, gate controls, alarm panels, and automotive RKE. Typical applications include garage-door and gate openers, automotive Remote Keyless Entry transmitters, wireless doorbells, alarm and security system keypads, asset-tracking fobs, and industrial access-control handheld remotes. Pair it with a Microchip HCS compatible receiver decoder (e.g., the receiver side of the HCS family) to complete a one-way secure link. When designing with the HCS361-I/P, observe the VDD decoupling guidance from the datasheet (a 0.1 µF ceramic cap close to the VDD pin), the RF section layout for the companion transmitter PCB, and the four-button debounce pattern in Microchip application notes. The industrial -40 °C to +85 °C range makes this part suitable for outdoor fobs and unheated enclosures, while the through-hole PDIP-8 package simplifies hand-soldering and prototype builds. This page synthesizes distributor pricing, drop-in package alternatives, and practical design notes not found in the manufacturer datasheet alone.
HEF4047BT - CMOS Monostable/Astable Multivibrator SOIC-14
The Nexperia (formerly NXP Semiconductors) HEF4047BT is a CMOS monostable/astable multivibrator housed in a 14-pin SOIC (SOT108) surface-mount package. It is a retriggerable astable multivibrator that can be configured as either a positive-edge or negative-edge triggered monostable multivibrator, with output pulse width programmed by external resistor Rt and capacitor Ct. The device includes clamp diodes on inputs, enabling the use of current limiting resistors to interface to voltages in excess of VCC. A multivibrator is a fundamental digital timing element that produces pulse waveforms without a stable DC state, or a single controlled-width pulse (monostable) from a trigger event. Within the digital-IC taxonomy, the HEF4047BT sits in the specialty-logic family of CMOS logic ICs, branching from the broader 4000-series CMOS logic line. Its core role in system design is generating precise time delays or square-wave clocks without software overhead, complementing microcontrollers and PLLs in mixed-signal designs. Key features include wide supply voltage operation from 4.5 V to 15.5 V, low quiescent current of typically 2.4 mA, 50 ns propagation delay, monostable and astable modes in a single device, retriggerable operation, and master reset. The SOIC-14 package provides ease of assembly on standard reflow profiles with MSL Level 1 moisture sensitivity. Internally the HEF4047BT uses CMOS logic gates combined with an external RC timing network to set the output pulse width or oscillation frequency. Its high noise immunity (typical of 4000-series CMOS) and low power consumption make it well-suited to battery-powered and industrial environments. The retrigger capability allows the output pulse to be extended by repeated triggers within the timing window. Typical applications include missing-pulse detection, bounce-free switches, frequency discriminators, timing circuits, clock-pulse generation, and monostable multivibrators for digital debounce in industrial controls, instrumentation, and consumer electronics. Engineers often pair it with the CD4013 or CD4093 for cascaded timing chains. When designing with the HEF4047BT, select Rt and Ct to place the timing well within the part's specified range, keep Rt traces short to avoid stray capacitance pickup, and bypass VCC with a 100 nF ceramic capacitor placed close to pin 14. Note that the HEF4047BT,653 reel-pack variant and HEF4047BT,652 bulk-pack variant share identical silicon and pinout. This page synthesizes distributor pricing, drop-in SOIC-14 alternatives, and practical design notes not found in the manufacturer datasheet alone, including cross-vendor substitutes such as CD4047BCN from onsemi and HCF4047 from STMicroelectronics.