PIC16LC74BT-04I/PQ - 8-Bit 4MHz MCU 7KB OTP 44-MQFP | Microchip
MPN: PIC16LC74BT-04I/PQ β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.2 | $162.00 |
| 100 | $13.75 | $1,375.00 |
| 500 | $11.9 | $5,950.00 |
| 1,000 | $10.5 | $10,500.00 |
PIC16LC74BT-04I/PQ Overview
A microcontroller (MCU) is a single-chip computer containing a CPU, memory, and programmable I/O peripherals. The PIC16LC74BT-04I/PQ belongs to the PIC16C mid-range architecture family, which sits within the broader 8-bit microcontroller hierarchy (8-bit MCU -> microcontroller -> embedded processor -> semiconductor). This 'C' family uses a 14-bit instruction word, characteristic of Microchip's mid-range devices, balancing code density with peripheral integration. Its 'LC' prefix designates the low-power CMOS variant, and the 'T' indicates tape-and-reel packaging.
Key features include 192 bytes of data RAM, hardware peripherals such as PWM modules, a Watchdog Timer (WDT), Brown-Out Reset (BOR), and Power-On Reset (POR), and an 8-bit ADC with 5 analog input channels. The device supports in-circuit serial programming (ICSP) via two lines and operates across an extended industrial temperature range of -40 Β°C to +85 Β°C, marked by the 'I' suffix in the part number.
Architecturally, the PIC16LC74B uses Harvard architecture with separate program and data buses, executed through a fully static RISC core. The fully-static design allows the clock to be halted for low-power standby. Program memory is OTP (One-Time Programmable), making this part ideal for high-volume production where firmware is finalized and code revision is no longer required.
Typical applications include industrial automation, consumer electronics, automotive subsystems, sensor interfacing, and motor-control prototyping. The integrated PWM and ADC make it a common choice for closed-loop analog control nodes in legacy embedded designs.
When designing with this MCU, ensure the OTP window is correctly shielded from UV exposure to prevent inadvertent code erasure. Adequate decoupling (100 nF ceramic plus bulk capacitance) near VDD pins is essential for ADC accuracy and noise immunity.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes that are not consolidated in any single manufacturer datasheet, providing a higher-density reference for engineers evaluating long-lifecycle or EOL components.
Drop-in alternatives for PIC16LC74BT-04I/PQ β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC16LC74BT-04I/PQ (same form factor and footprint) β differing in Core Architecture, Package, Program Memory Size, ADC, Timers.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16LC74BT-04/PQ
β Drop-Inπ Reference alternative (not in catalog)
PIC16LC74B-04I/PQ
β Drop-Inπ Reference alternative (not in catalog)
PIC16LC74B-04/PQ
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16F74-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16LC74BT-04I/PQ Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C Mid-Range (Harvard, 14-bit instruction word) |
| Bit Width | 8-bit |
| Maximum CPU Frequency | 4 MHz |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| Data RAM | 192 bytes |
| Digital I/O Pins | 33 |
| ADC | 8-bit, 5 channels |
| PWM Modules | Yes |
| Watchdog Timer (WDT) | Yes |
| Brown-Out Reset (BOR) | Yes |
| Power-On Reset (POR) | Yes |
| In-Circuit Serial Programming | ICSP |
| Supply Voltage Range | 2.5 V to 5.5 V |
| Operating Temperature Range | -40 Β°C to +85 Β°C (Industrial) |
| Package | 44-MQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC16LC74BT-04I/PQ Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (Reset) input / Programming voltage |
| Pin 2 | RA0/AN0 β Digital I/O / ADC analog input 0 |
| Pin 3 | RA1/AN1 β Digital I/O / ADC analog input 1 |
| Pin 4 | RA2/AN2 β Digital I/O / ADC analog input 2 |
| Pin 5 | RA3/AN3/VREF β Digital I/O / ADC analog input 3 / ADC reference |
| Pin 6 | RA4/T0CKI β Digital I/O / Timer 0 clock input |
| Pin 7 | RA5/AN4/SS β Digital I/O / ADC analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 β Digital I/O / Parallel read / analog input 5 |
| Pin 9 | RE1/WR/AN6 β Digital I/O / Parallel write / analog input 6 |
| Pin 10 | RE2/CS/AN7 β Digital I/O / Parallel chip select / analog input 7 |
| Pin 11 | VDD β Power supply +2.5V to +5.5V |
| Pin 12 | VSS β Ground |
| Pin 13 | OSC1/CLKIN β Oscillator crystal input / external clock |
| Pin 14 | OSC2/CLKOUT β Oscillator crystal output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI β Digital I/O / Timer1 oscillator output / clock |
| Pin 16 | RC1/T1OSI/CCP2 β Digital I/O / Timer1 oscillator input / Capture-Compare-PWM |
| Pin 17 | RC2/CCP1 β Digital I/O / Capture-Compare-PWM 1 |
| Pin 18 | RC3/SCK/SCL β Digital I/O / SPI SCK / I2C SCL |
| Pin 19 | RC4/SDI/SDA β Digital I/O / SPI data in / I2C data |
| Pin 20 | RC5/SDO β Digital I/O / SPI data out |
| Pin 21 | RC6/TX/CK β Digital I/O / USART TX / clock |
| Pin 22 | RC7/RX/DT β Digital I/O / USART RX / data |
| Pin 23 | RB0/INT β Digital I/O / External interrupt |
| Pin 24 | RB1 β Digital I/O |
| Pin 25 | RB2 β Digital I/O |
| Pin 26 | RB3 β Digital I/O |
| Pin 27 | RB4 β Digital I/O |
| Pin 28 | RB5 β Digital I/O |
| Pin 29 | RB6/PGC β Digital I/O / Programming clock (ICSP) |
| Pin 30 | RB7/PGD β Digital I/O / Programming data (ICSP) |
| Pin 31 | RD0/PSP0 β Digital I/O / Parallel Slave Port bit 0 |
| Pin 32 | RD1/PSP1 β Digital I/O / Parallel Slave Port bit 1 |
| Pin 33 | RD2/PSP2 β Digital I/O / Parallel Slave Port bit 2 |
| Pin 34 | RD3/PSP3 β Digital I/O / Parallel Slave Port bit 3 |
| Pin 35 | RD4/PSP4 β Digital I/O / Parallel Slave Port bit 4 |
| Pin 36 | RD5/PSP5 β Digital I/O / Parallel Slave Port bit 5 |
| Pin 37 | RD6/PSP6 β Digital I/O / Parallel Slave Port bit 6 |
| Pin 38 | RD7/PSP7 β Digital I/O / Parallel Slave Port bit 7 |
| Pin 39 | NC β Not connected (per datasheet) |
| Pin 40 | NC β Not connected (per datasheet) |
| Pin 41 | NC β Not connected (per datasheet) |
| Pin 42 | NC β Not connected (per datasheet) |
| Pin 43 | NC β Not connected (per datasheet) |
| Pin 44 | NC β Not connected (per datasheet) |
Typical Applications
PIC16LC74BT-04I/PQ is suitable for 6 applications: Industrial Automation Controllers, Consumer Electronics Remote Controls, Automotive Sensor Interface Modules, Sensor Signal Conditioning Nodes, Hobbyist and Educational Embedded Kits, Low-Volume Embedded Control Retrofits.
Industrial Automation Controllers
The PIC16LC74BT-04I/PQ fits industrial automation controllers where its 4 MHz core, 7 KB OTP, and industrial -40 Β°C to +85 Β°C temperature range address PLC I/O expansion modules and machine-status monitoring nodes. The 33 digital I/O pins accommodate multiple sensor inputs and relay outputs, while the integrated 8-bit ADC with 5 channels digitizes 4-20 mA loopback signals from pressure or flow transducers. Compared to a flash MCU, the OTP variant locks firmware, eliminating field reprogramming risk in factory-floor deployments where code tampering must be prevented. Brown-Out Reset and Power-On Reset protect against brownouts common in industrial supply rails; place a 100 nF ceramic plus 10 Β΅F bulk capacitor within 5 mm of VDD pins for stable ADC accuracy. PWM outputs drive proportional valves or indicator dimming.
Recommended
Consumer Electronics Remote Controls
The PIC16LC74BT-04I/PQ serves consumer IR remote controls and appliance user interfaces where its 7 KB OTP holds fixed command sets, 192 B RAM buffers button scans, and 33 I/O drives key matrices and LED indicators. Its 2.5β5.5 V supply range supports single-cell lithium or 3Γ AAA battery stacks common in remotes, and low-power CMOS design extends battery life. The integrated PWM channels modulate IR carrier frequencies for consumer protocols (NEC, RC5); the on-chip 8-bit ADC reads battery voltage for low-battery warnings via on-screen display. OTP memory prevents end-user firmware tampering, an advantage over flash parts. Decouple VDD with 100 nF ceramic, and add a 10 kΞ© pull-up on MCLR to prevent spurious resets during battery hot-plug events.
Recommended
Automotive Sensor Interface Modules
The PIC16LC74BT-04I/PQ integrates into automotive sensor interfaces including seat-occupancy detectors, HVAC flap controllers, and rain-light sensor ECUs, where its -40 Β°C to +85 Β°C industrial range (and reported automotive use per Microchip) handles under-dash thermal stress. The 5-channel 8-bit ADC digitizes thermistor, photodiode, or Hall-effect sensor outputs, while PWM signals drive indicator LEDs or small actuators. Brown-Out Reset prevents corrupted sensor reads during engine-crank voltage dips; an external TVS diode across VDD handles load-dump transients. The 4 MHz clock rate is sufficient for 10 ms control loops typical of body-electronics. OTP memory locks compliance firmware, ensuring sensor calibration cannot be altered in the field. Note: AEC-Q100 qualification is not explicitly stated in the datasheet for this OTP variant.
Recommended
Sensor Signal Conditioning Nodes
The PIC16LC74BT-04I/PQ acts as a sensor signal-conditioning front-end where the 8-bit 5-channel ADC digitizes strain-gauge, thermistor, or optical sensor outputs, and 33 I/O pins route processed signals to a host processor or display. At 4 MHz, the MCU executes calibration algorithms (linearization, offset compensation) and statistics filtering on each ADC channel within the 4 Β΅S minimum acquisition window. OTP memory holds factory-calibrated coefficients, ensuring each node ships with consistent accuracy. The 192-byte RAM is sufficient for last-32-sample rolling averages used to suppress HVAC and EMI noise. Connect ADC inputs through RC low-pass filters (1 kΞ© + 100 nF) and bypass VDD with separate analog/digital supply pins to maximize ADC monotonic performance per datasheet guidelines.
Recommended
Hobbyist and Educational Embedded Kits
The PIC16LC74BT-04I/PQ is widely used in introductory microcontroller training kits and hobby robotics controllers because its 33 I/O accommodates servo motors, sensors, and character-LCD displays while 7 KB OTP holds complete sample programs. The Harvard RISC architecture provides single-cycle instruction execution, ideal for teaching register-level programming. In-Circuit Serial Programming (ICSP) via two lines enables students to download tutorials without removing the chip from the board. The PIC16CXX mid-range instruction set, with only 35 instructions, eases the learning curve. The 8-bit ADC and PWM modules demonstrate analog-to-digital conversion and proportional control concepts. While obsolete for new commercial designs, the device remains pedagogically valuable; pair a PICkit 3 programmer with the chip for laboratory use.
Recommended
Low-Volume Embedded Control Retrofits
The PIC16LC74BT-04I/PQ is frequently deployed in low-volume retrofits of legacy industrial equipment where the original 16C-series MCU is now obsolete. Its -40 Β°C to +85 Β°C range and 4 MHz core match the cycle-time requirements of 1990s-era controllers, while its 7 KB OTP holds fixed replacement firmware. The 33 I/O pins map cleanly to legacy pin assignments, allowing drop-in PCB replacement without redesign. The integrated 8-bit ADC with 5 channels handles legacy analog inputs (potentiometers, current-loop sensors) without external ADC chips. Brown-Out Reset and Watchdog Timer match the supervisory features of the original equipment. Use socketed installation to allow future migration to PIC16F74 or PIC18F successors when spare parts run out.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74BT-04I/PQ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC74BT-04/PQ | PIC16LC74B-04I/PQ | PIC16F74-I/PT | PIC16LC74B-04/PQ |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-MQFP (10x10 mm) | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-TQFP (10x10) - same footprint | 44-MQFP (10x10) - same |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 4 KB Flash | 7 KB OTP |
| Maximum Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 4 MHz |
| Data RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Digital I/O | 33 | 33 | 33 | 33 | 33 |
| ADC | 8-bit, 5 channels | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch |
| Operating Temperature | -40 Β°C to +85 Β°C | 0 Β°C to +70 Β°C | -40 Β°C to +85 Β°C | -40 Β°C to +85 Β°C | 0 Β°C to +70 Β°C |
| Memory Type | OTP | OTP | OTP | Flash (in-system reprogrammable) | OTP |
| Lifecycle Status | Obsolete (EOL) | Obsolete | Obsolete | Active | Obsolete |
Key Differentiators
- Industrial temperature grade with OTP code lock (vs PIC16F74-I/PT)
- Identical silicon across T and non-T suffixes (vs PIC16LC74BT-04/PQ)
- 5-channel 8-bit ADC integration (vs PIC16LC65BT-04I/PQ)
Design Notes
Bypass VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD pins (pin 11 and pin 32 in this package). Add a 10 Β΅F bulk capacitor on the supply rail. The PIC16LC74BT-04I/PQ's internal POR/BOR requires a clean VDD rise time below the BOR threshold specification; if supply ramp exceeds 100 ms, add an external RC delay on MCLR to ensure reset. Brown-out reset triggers at approximately 4.0 V on 5 V rails per datasheet - validate threshold against your regulator tolerance.
Place the decoupling capacitor as close as possible to VDD pins, ideally with vias connecting to an inner ground plane. Keep the oscillator traces (OSC1/OSC2) short and shielded by an analog ground island. If using the internal RC oscillator, leave OSC1 grounded and OSC2 floating per datasheet. Separate analog and digital grounds to a single-point star connection near VSS pin to minimize ADC switching noise coupling.
OTP (one-time-programmable) memory cannot be erased; verify firmware with an emulator or windowed sample before committing to masked/OTP production orders. Do not exceed 13.5 V on MCLR/VPP during in-circuit programming or the device may be permanently damaged. The Parallel Slave Port pins (RD0-RD7) require explicit TRIS configuration; floating PSP pins cause excessive supply current. Always set unused I/O pins as outputs or enable internal weak pull-ups to reduce standby current below 5 Β΅A specification.
Compliance Information
RoHS compliant and lead-free per Microchip product declaration. AEC-Q100 qualification not explicitly stated in available datasheet excerpts. REACH and halogen-free status not confirmed in provided data; request latest material declaration from Microchip as device is classified obsolete.
