PIC16LC74B-04I/L - 8-Bit 4MHz PIC MCU 7KB OTP 44-PLCC | Microchip
MPN: PIC16LC74B-04I/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.95 | $9.95 |
| 10 | $9.2 | $92.00 |
| 100 | $8.45 | $845.00 |
| 500 | $7.6 | $3,800.00 |
| 1,000 | $6.95 | $6,950.00 |
PIC16LC74B-04I/L Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program memory, working RAM, and configurable I/O peripherals. The PIC16LC74B belongs to the RISC (Reduced Instruction Set Computer) family, which executes instructions in a single cycle (except program branches, which require two cycles). Within the broader semiconductor taxonomy, MCUs are part of integrated circuits in the microcontroller sub-category, sitting beneath logic ICs and alongside microprocessors in embedded computing hierarchies. Only 35 single-word instructions are required to program the device, dramatically reducing development complexity for embedded engineers.
Key features include a 200 ns instruction cycle at 20 MHz maximum clock, hardware peripherals such as timers, a USART for serial communication, and a multi-channel 8-bit ADC. The OTP memory supports one-time programming for production units, while the LC suffix denotes the low-power CMOS process variant optimized for 3.3 V battery-powered designs. The 33 I/O pins are organized into multiple ports with individual direction control, supporting digital input/output, peripheral functions, and interrupt-driven event responses. Industrial-grade temperature range (-40C to +85C) is indicated by the "I" suffix in the part number.
The PIC16LC74B-04I/L is widely deployed in industrial control systems, instrumentation, low-power embedded appliances, sensor interfaces, and legacy 8-bit designs requiring deterministic interrupt response. It is also commonly used in educational platforms and prototyping environments. The 44-PLCC package provides through-hole mounting with J-leads, allowing socket-based development and field replacement. According to Microchip product documentation, the LC variant targets portable and battery-operated applications where current consumption must remain below a few milliamps in typical operating modes.
When designing with this part, verify that the OTP memory size (7 KB) is sufficient for your firmware image and select the appropriate oscillator configuration (XT, HS, RC, or LP) for your system clock. The "04" speed grade denotes 4 MHz maximum operation, suitable for low-power timing-sensitive applications. This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16LC74B-04I/L — 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 PIC16LC74B-04I/L (same form factor and footprint) — differing in Mounting Type, Timers, Program Memory Size, ADC, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74B-04I/L
✅ Drop-In✓ In Stock
$2.61 / Unit
View Datasheet →PIC16LC74A-04I/L
✅ Drop-In✓ In Stock
$3.79 / Unit
View Datasheet →PIC16LC74B-04/L
✅ Drop-In✓ In Stock
$5.95 / Unit
View Datasheet →PIC16LC74B-04I/L Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit RISC (PIC16CXX mid-range) |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns (at 20 MHz) |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 bytes |
| Number of I/O Pins | 33 |
| Operating Voltage | 3.0 V to 5.5 V |
| Instruction Set | 35 single-word instructions |
| Package Type | 44-pin PLCC (Plastic Leaded Chip Carrier) |
| Package Dimensions | 16.59 mm x 16.59 mm |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Mounting Type | Surface Mount (J-Lead) |
| Speed Grade | 04 (4 MHz) |
| Temperature Grade Suffix | I (Industrial, -40C to +85C) |
PIC16LC74B-04I/L Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (Reset) input / Programming voltage |
| Pin 2 | OSC1/CLKIN — Oscillator crystal input / External clock |
| Pin 3 | OSC2/CLKOUT — Oscillator crystal output / Clock output |
| Pin 4 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 5 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 6 | RA2/AN2 — PORTA bit 2 / Analog input 2 |
| Pin 7 | RA3/AN3/VREF — PORTA bit 3 / Analog input 3 / Voltage reference |
| Pin 8 | RA4/T0CKI — PORTA bit 4 / Timer 0 clock input |
| Pin 9 | RA5/AN4/SS — PORTA bit 5 / Analog input 4 / SPI slave select |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 13 | RB1 — PORTB bit 1 |
| Pin 14 | RB2 — PORTB bit 2 |
| Pin 15 | RB3 — PORTB bit 3 |
| Pin 16 | RB4 — PORTB bit 4 |
| Pin 17 | RB5 — PORTB bit 5 |
| Pin 18 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 19 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 20 | VSS — Ground reference |
| Pin 21 | VDD — Positive supply voltage |
| Pin 22 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer 1 oscillator output / clock input |
| Pin 23 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer 1 oscillator input / CCP2 |
| Pin 24 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 25 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 26 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 27 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 28 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 29 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 30 | VSS — Ground reference |
| Pin 31 | VDD — Positive supply voltage |
| Pin 32 | RD0 — PORTD bit 0 |
| Pin 33 | RD1 — PORTD bit 1 |
| Pin 34 | RD2 — PORTD bit 2 |
| Pin 35 | RD3 — PORTD bit 3 |
| Pin 36 | RD4 — PORTD bit 4 |
| Pin 37 | RD5 — PORTD bit 5 |
| Pin 38 | RD6 — PORTD bit 6 |
| Pin 39 | RD7 — PORTD bit 7 |
| Pin 40 | VSS — Ground reference |
| Pin 41 | VDD — Positive supply voltage |
| Pin 42 | RE0/RD — PORTE bit 0 / Parallel port read control |
| Pin 43 | RE1/WR — PORTE bit 1 / Parallel port write control |
| Pin 44 | RE2/CS — PORTE bit 2 / Parallel port chip select |
Typical Applications
PIC16LC74B-04I/L is suitable for 6 applications: Industrial Control Systems, Sensor Interface Modules, Battery-Powered Embedded Devices, Legacy Appliance Control, Educational and Prototyping Platforms, Instrumentation and Data Acquisition.
Industrial Control Systems
The PIC16LC74B-04I/L fits industrial control with 33 I/O pins for sensor/actuator interfacing, 4 MHz clock for deterministic timing, and -40C to +85C industrial temperature range. The LC process variant draws low current at 3.3 V, suitable for control panels with battery backup. The OTP memory supports high-volume production with locked firmware; the 35-instruction RISC core enables compact assembly code for PID loops and state machines typical in factory automation.
Recommended
Sensor Interface Modules
With 33 digital I/O pins and an 8-bit RISC core, the PIC16LC74B-04I/L suits multi-sensor interface modules reading temperature, pressure, and switch inputs. The 192-byte RAM handles small data buffers, while the 7 KB OTP memory stores protocol stacks for I2C/SPI sensor interfacing. Low-voltage operation at 3.3 V matches modern sensor modules directly, eliminating level translation. The 4 MHz clock enables 1 ms loop rates for environmental monitoring and HVAC sensor nodes.
Recommended
Battery-Powered Embedded Devices
The PIC16LC74B-04I/L low-power LC process makes it suitable for battery-powered devices operating from 3.3 V lithium cells. The CMOS design draws minimal current in sleep modes, extending battery runtime for portable instrumentation. The 33 I/O pins support LCD drivers, keypad scanning, and serial communication. The 4 MHz clock is adequate for low-duty-cycle measurement and logging tasks, while the 7 KB OTP memory holds compact firmware images for production.
Recommended
Legacy Appliance Control
The PIC16LC74B-04I/L serves in legacy appliance control boards where deterministic response and reliability are critical. Washing machines, dishwashers, and HVAC controllers use PIC16 mid-range MCUs for motor control, timing sequences, and user-interface scanning. The 33 I/O pins handle relay drivers, button matrices, and seven-segment displays. The OTP memory locks firmware once production programming is complete, preventing field tampering and ensuring code integrity throughout product lifetime.
Recommended
Educational and Prototyping Platforms
The PIC16LC74B-04I/L is used in educational platforms teaching embedded programming with RISC architecture. Only 35 single-word instructions reduce the learning curve for students exploring assembly and embedded C programming. The 44-PLCC socket-compatible package allows easy replacement on development boards. With 7 KB OTP and 192-byte RAM, students can implement timer-based, interrupt-driven, and peripheral-interfacing projects representative of real-world embedded design.
Recommended
Instrumentation and Data Acquisition
The PIC16LC74B-04I/L fits low-channel-count data acquisition front-ends where 8-bit ADC resolution and 33 I/O pins suffice. The 4 MHz clock supports 100 ksps sampling with software averaging for noise reduction. The 192-byte RAM buffers small acquisition windows before serial transmission. Industrial temperature grade -40C to +85C supports process instrumentation panels and outdoor monitoring stations. OTP memory locks calibration coefficients and protocol handlers for production deployment.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74B-04I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74B-04I/L | PIC16LC74A-04I/L | PIC16LC74B-04/L |
|---|---|---|---|---|
| Package | 44-PLCC (16.59 x 16.59 mm) | 44-PLCC (same) | 44-PLCC (same) | 44-PLCC (same) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| I/O Pins | 33 | 33 | 33 | 33 |
| Operating Voltage | 3.0 V to 5.5 V | 4.0 V to 6.0 V (5 V process) | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
| Temperature Range | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) |
| Process Variant | LC (low-power CMOS) | C (standard CMOS, 5 V) | LC (low-power CMOS) | LC (low-power CMOS) |
Key Differentiators
- Low-power LC process variant optimized for 3.3 V operation (vs PIC16C74B-04I/L)
- Industrial temperature range -40 C to +85 C (vs PIC16LC74B-04/L)
- Same 44-PLCC footprint with identical 35-instruction RISC core (vs PIC16LC74A-04I/L)
Design Notes
The PIC16LC74B-04I/L operates from 3.0 V to 5.5 V supply and uses multiple VDD/VSS pin pairs (pins 11/10, 21/20, 31/30, 41/40) that must all be connected for proper operation. Decoupling: place a 0.1 uF ceramic capacitor close to each VDD pin pair and a bulk 10 uF tantalum or aluminum electrolytic capacitor at the board's power entry point. The LC process variant draws significantly less current than the C variant at equivalent clock rates, especially in sleep mode where current drops to microampere levels.
The 44-pin PLCC package uses J-lead surface-mount construction with socket-compatible through-hole adapter sockets available for development. Place the crystal or external oscillator within 1 cm of pins 2-3 (OSC1/OSC2) to minimize parasitic capacitance. Route MCLR (pin 1) with a 10 kohm pull-up resistor and consider adding a 100 nF capacitor to ground for noise filtering. Keep analog signals (PORTA) physically separated from digital signals and high-current traces to reduce ADC noise coupling.
Critical pitfalls when designing with PIC16LC74B-04I/L: (1) OTP memory can only be programmed once - verify firmware with flash prototype before committing to OTP parts; (2) the 4 MHz speed grade does not allow 20 MHz operation - choose PIC16LC74B-20I/L for higher-speed needs; (3) the I temperature suffix indicates industrial range - commercial boards (0C to +70C) use the part without I; (4) brown-out detection must be enabled in firmware or external supervisor used to prevent code corruption at low VDD; (5) unused I/O pins should be configured as outputs low or inputs with pull-ups to minimize current consumption.
Compliance Information
Compliance status not explicitly stated in verified web data; marked as unknown per Data Authenticity Rules. NRND lifecycle status indicates Microchip does not recommend new design adoption. Refer to Microchip product compliance documentation for RoHS/REACH certifications.
