PIC16LC74B-04I/P - 8-Bit 4MHz CMOS MCU 7KB OTP 40-PDIP | Microchip
MPN: PIC16LC74B-04I/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.27 | $3.27 |
| 10 | $3.05 | $30.50 |
| 100 | $2.78 | $278.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.12 | $2,120.00 |
PIC16LC74B-04I/P Overview
A mid-range PIC microcontroller is an 8-bit Harvard-architecture device that separates program and data memory to allow simultaneous fetching, enabling deterministic single-cycle instruction execution. Within Microchip's broader taxonomy, the PIC16LC74B sits in the PIC16C mid-range family, which evolved into the PIC16F flash family in the late 1990s. Today the device is positioned as a legacy OTP MCU used in designs where flash-based PIC16F1xxx migration is not desired or where the OTP cost model fits the application.
Key features of the PIC16LC74B-04I/P include 192 bytes of data RAM, five 8-bit I/O ports (PORTA..PORTE), three timer/counters, a USART, an SSP module supporting SPI and I2C, an 8-channel 8-bit ADC, and capture/compare/PWM peripherals. The 33 I/O pins support individual direction control, and the device includes a watchdog timer with its own on-chip RC oscillator for reliable recovery from software lockups. The OTP program memory allows the device to be programmed once and retain its code indefinitely.
Typical applications include industrial control panels, appliance controllers, sensor interface modules, low-cost remote controls, and legacy embedded systems where the OTP memory model fits the production programming strategy. When designing with this MCU, ensure the maximum operating frequency of 4 MHz is respected and that the brown-out reset and watchdog timer are properly configured for the application environment.
Drop-in alternatives for PIC16LC74B-04I/P — 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/P (same form factor and footprint) — differing in Mounting Type, Core, Program Memory Type, Package, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F74-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C74B-04/PQ
✅ Drop-In✓ In Stock
$7.25 / Unit
View Datasheet →PIC16C74B-04I/P
✅ Drop-In✓ In Stock
$5.55 / Unit
View Datasheet →PIC16LC74A-04/PQ
✅ Drop-In✓ In Stock
$2.43 / Unit
View Datasheet →PIC16LC74B-04I/PQ
✅ Drop-In✓ In Stock
$7.6 / Unit
View Datasheet →PIC16LC74B-04I/P Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC 16C |
| Core Processor | PIC |
| Core Size | 8-Bit |
| Maximum Clock Frequency | 4 MHz |
| Program Memory Size | 7 KB (4K x 14) OTP |
| RAM Size | 192 B |
| Number of I/O Pins | 33 |
| Package Type | 40-pin PDIP |
| Mounting Type | Through Hole |
| Operating Temperature Range | -40 C to +85 C (industrial, "I" grade) |
| Oscillator Type | External (per -04 speed grade, max 4 MHz) |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT, USART, SSP (SPI/I2C) |
| Connectivity | UART/USART, SPI, I2C (SSP) |
| Program Memory Type | OTP (One-Time Programmable) |
| RoHS Status | Unknown (PDIP package variant) |
PIC16LC74B-04I/P Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / Programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit0 / Analog channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit1 / Analog channel 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit2 / Analog channel 2 / ADC negative reference |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit3 / Analog channel 3 / ADC positive reference |
| Pin 6 | RA4/T0CKI — PORTA bit4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit5 / Analog channel 4 / SPI slave select |
| Pin 8 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 9 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit0 / Timer1 oscillator output / Timer1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit1 / Timer1 oscillator input / CCP2 module |
| Pin 12 | RC2/CCP1 — PORTC bit2 / CCP1 PWM/capture/compare |
| Pin 13 | RC3/SCK/SCL — PORTC bit3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — PORTC bit4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO — PORTC bit5 / SPI data out |
| Pin 16 | RC6/TX/CK — PORTC bit6 / USART TX / USART clock |
| Pin 17 | RC7/RX/DT — PORTC bit7 / USART RX / USART data |
| Pin 18 | RD0/PSP0 — PORTD bit0 / Parallel Slave Port bit0 |
| Pin 19 | RD1/PSP1 — PORTD bit1 / Parallel Slave Port bit1 |
| Pin 20 | RD2/PSP2 — PORTD bit2 / Parallel Slave Port bit2 |
| Pin 21 | RD3/PSP3 — PORTD bit3 / Parallel Slave Port bit3 |
| Pin 22 | RD4/PSP4 — PORTD bit4 / Parallel Slave Port bit4 |
| Pin 23 | RD5/PSP5 — PORTD bit5 / Parallel Slave Port bit5 |
| Pin 24 | RD6/PSP6 — PORTD bit6 / Parallel Slave Port bit6 |
| Pin 25 | RD7/PSP7 — PORTD bit7 / Parallel Slave Port bit7 |
| Pin 26 | VSS — Ground reference |
| Pin 27 | VDD — Positive supply voltage |
| Pin 28 | RE0/RD/AN5 — PORTE bit0 / Read control / Analog channel 5 |
| Pin 29 | RE1/WR/AN6 — PORTE bit1 / Write control / Analog channel 6 |
| Pin 30 | RE2/CS/AN7 — PORTE bit2 / Chip select / Analog channel 7 |
| Pin 31 | RB0/INT — PORTB bit0 / External interrupt |
| Pin 32 | RB1 — PORTB bit1 |
| Pin 33 | RB2 — PORTB bit2 |
| Pin 34 | RB3 — PORTB bit3 |
| Pin 35 | RB4 — PORTB bit4 |
| Pin 36 | RB5 — PORTB bit5 |
| Pin 37 | RB6/PGC — PORTB bit6 / ICSP clock (programming/debug) |
| Pin 38 | RB7/PGD — PORTB bit7 / ICSP data (programming/debug) |
| Pin 39 | NC — Not connected (per datasheet) |
| Pin 40 | NC — Not connected (per datasheet) |
Typical Applications
PIC16LC74B-04I/P is suitable for 6 applications: Industrial Control Panels, Appliance Controllers, Sensor Interface Modules, Low-Cost Remote Controls, Legacy Embedded Systems, Educational and Hobby Projects.
Industrial Control Panels
The PIC16LC74B-04I/P suits industrial control panels requiring 33 I/O pins for keypad scanning, LED matrix driving, and relay switching. Its 7 KB OTP memory holds menu logic, while the USART provides RS-232 communication with HMIs. The -40C to +85C industrial temperature range supports factory floor and outdoor cabinet deployment without thermal derating. The integrated ADC reads sensor inputs (temperature, pressure) while the SSP supports I2C peripherals. The 4 MHz clock is sufficient for panel update rates and slow control loops.
Recommended
Appliance Controllers
The PIC16LC74B-04I/P's 33 I/O lines and PWM/capture modules suit washing machine, dishwasher, and oven control boards driving relays, triacs, and motor bridges. The 192-byte RAM handles user-interface state, while the OTP 7 KB program memory stores the appliance cycle logic. The "LC" low-power process reduces standby current for Energy Star-rated appliances, and the industrial temperature range survives the heat of motor compartments. The USART supports service-diagnostic interface and the ADC reads thermistor inputs.
Recommended
Sensor Interface Modules
The PIC16LC74B-04I/P integrates an 8-channel 8-bit ADC and SPI/I2C ports to consolidate sensor data from multiple sources into a single protocol output. The 33 I/O pins accommodate parallel sensor arrays, while the 192-byte RAM buffers readings before USART transmission. Its industrial -40C to +85C range makes it suitable for HVAC, building automation, and outdoor environmental monitoring. The brown-out reset and watchdog timer protect against sensor glitches and supply noise in industrial environments.
Recommended
Low-Cost Remote Controls
The PIC16LC74B-04I/P's low-power "LC" process and modest 4 MHz clock fit handheld battery-powered remote controls transmitting IR or RF commands. The 33 I/O lines connect to keypad matrices and LED indicators, while the 7 KB OTP memory holds the protocol stack and button mappings. The capture module decodes IR receiver inputs for learning-remote applications. Its industrial temperature range covers outdoor remote use, and the brown-out reset protects against battery-low misoperation.
Recommended
Legacy Embedded Systems
The PIC16LC74B-04I/P continues to support legacy industrial, automotive-aftermarket, and educational designs using the PIC16C mid-range instruction set. Its 4 MHz operation with 200 ns instruction cycle matches the original PIC16C74 timing assumptions in legacy firmware. The 33 I/O pin count preserves backward compatibility with older I/O expansion boards. While NRND status limits new designs, existing production boards benefit from continued limited-stock availability for repair and refurbishment.
Recommended
Educational and Hobby Projects
The PIC16LC74B-04I/P remains popular in university courses and hobby projects teaching mid-range PIC assembly programming and embedded C. Its 35-instruction RISC core, 7 KB OTP memory, and rich peripheral set (ADC, PWM, USART, SPI, I2C) provide a comprehensive learning platform. The 40-pin PDIP package is breadboard-friendly, allowing easy prototyping without fine-pitch soldering. Industrial temperature rating supports classroom lab environments and field demonstration projects.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC74B-04I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F74-I/P | PIC16C74B-04/P | PIC16C74B-04I/P | PIC16LC74B-04I/PQ |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 40-PDIP (through-hole) | 40-PDIP (same) | 40-PDIP (same) | 40-PDIP (same) | 44-PQFP (different) |
| Core | 8-bit PIC16C mid-range | 8-bit PIC16F mid-range | 8-bit PIC16C mid-range | 8-bit PIC16C mid-range | 8-bit PIC16C mid-range |
| Program Memory Type | 7 KB OTP | 7 KB Flash | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| Maximum Clock | 4 MHz | 20 MHz | 4 MHz | 4 MHz | 4 MHz |
| Operating Temperature | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) |
| RAM | 192 B | 192 B | 192 B | 192 B | 192 B |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Lifecycle Status | NRND | Active | NRND | NRND | NRND |
| Low-Power CMOS Process | Yes (LC variant) | Yes | No (standard CMOS) | No (standard CMOS) | Yes (LC variant) |
Key Differentiators
- Low-power "LC" process for battery-friendly operation (vs PIC16C74B-04I/P (standard CMOS variant))
- Industrial -40 C to +85 C operating temperature range (vs PIC16C74B-04/P (commercial 0 C to +70 C))
- 33 I/O pins with rich peripheral set (vs PIC16LC73B-04I/P (28 I/O pins))
- 35-instruction RISC core with deterministic timing (vs PIC16F84 (legacy 18-pin flash MCU))
Design Notes
The PIC16LC74B-04I/P uses the low-power "LC" CMOS process, yielding significantly lower quiescent current than the standard PIC16C74B. Estimated: at 4 MHz and 5V supply, active current is approximately 5 mA and standby current below 10 uA with watchdog disabled. Always provide bulk decoupling (10-47 uF) at VDD and a 100 nF ceramic bypass capacitor close to the VDD pin.
Place the 100 nF decoupling capacitor within 5 mm of the VDD pin (pin 27) and connect its ground return directly to VSS (pin 26) to reduce switching noise coupling into the ADC. The OSC1/OSC2 traces should be kept short and routed away from analog inputs to prevent clock noise from corrupting ADC readings. The MCLR/VPP pin requires a 10 kohm pull-up to VDD for normal operation and a series resistor when using ICSP programming.
Do not confuse the PIC16LC74B-04I/P (4 MHz grade) with the PIC16LC74B-20I/P (20 MHz grade) - the -20 variant operates up to 5x faster but requires firmware timing recalculation. The OTP memory can only be programmed once, so verify firmware with a flash-based PIC16F74 prototype before committing to OTP production. The PORTE pins (RE0/RE1/RE2) double as Parallel Slave Port control signals and must be disabled in ADCON1 if used as digital I/O.
At maximum operating frequency (4 MHz) and 5V supply, the PIC16LC74B-04I/P consumes approximately 5 mA active current, dissipating only 25 mW - well within the 40-pin PDIP's thermal envelope. Estimated: at industrial -40C to +85C operating range, no heatsink is required. However, in enclosed appliances near heat sources, derate clock frequency below 4 MHz if junction temperature approaches 100 C.
Compliance Information
RoHS compliance status not explicitly stated in verified web data; the 40-pin PDIP through-hole package is commonly produced with lead-containing solder and may require RoHS 7(a) exemption. AEC-Q100 automotive qualification not applicable - PIC16LC74B family is not automotive-grade. Compliance status should be verified per shipment from distributor documentation.
