PIC16C74B-04/PQ - 8-Bit 4MHz OTP MCU 7KB Flash | Microchip
MPN: PIC16C74B-04/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.45 | $12.45 |
| 10 | $11.2 | $112.00 |
| 100 | $9.85 | $985.00 |
| 500 | $8.4 | $4,200.00 |
| 1,000 | $7.25 | $7,250.00 |
PIC16C74B-04/PQ Overview
A microcontroller (MCU) is a single-chip computer containing a processor core, program memory, working RAM, and peripheral interfaces such as timers, A/D converters, and communication ports. Mid-range PIC microcontrollers occupy the middle of Microchip's 8-bit portfolio - more capable than the PIC16C5X baseline family and upward-compatible with PIC12CXXX devices, but predating the PIC18 enhanced family. The 'C' suffix in PIC16Cxx denotes OTP EPROM program memory, suitable for production runs where code stability is finalized but where in-circuit reprogrammability is not required; Flash-based 'F' variants are typically preferred for prototypes and field-updatable designs.
Key specifications include 8 channels of 8-bit Analog-to-Digital conversion, two additional 8-bit timers plus Timer0 and Timer1, two Capture/Compare/PWM (CCP) modules, and a synchronous serial port configurable as either 3-wire SPI or 2-wire I2C. A USART (Universal Synchronous/Asynchronous Receiver/Transmitter) provides asynchronous serial communication. The device supports high sink/source current of 25 mA per I/O, low standby current of 1 µA typical at 3V/32 kHz, and 15 µA typical operating current at 5V/4 MHz. Operating voltage spans 2.5V to 6.0V across commercial, industrial, and extended temperature grades.
The PIC16C74B architecture uses a Harvard-style RISC core with only 35 single-word instructions, simplifying firmware development and reducing code footprint. Its mid-range peripheral set - particularly the 8-channel ADC and dual CCP - positions it for analog signal acquisition, motor control, and industrial instrumentation. The wide operating voltage and temperature range extend use into automotive under-hood and harsh industrial environments.
Typical applications include industrial process control, motor drive interfaces, sensor signal conditioning, power supply monitoring, and embedded data acquisition systems. The 44-pin MQFP footprint suits designs where through-hole PDIP is too large but QFN is unavailable in the OTP memory configuration. When designing with the PIC16C74B-04/PQ, account for OTP memory constraints by finalizing firmware before programming, and consider the Flash-based PIC16F74 as a development substitute since both share the same die and pinout. This page synthesizes distributor pricing, drop-in PIC16C74B variants, and practical design notes not aggregated in any single manufacturer or distributor source.
Drop-in alternatives for PIC16C74B-04/PQ — 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 PIC16C74B-04/PQ (same form factor and footprint) — differing in RoHS Status, Timers, Core Architecture, Package, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74B-04I/PQ
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC16C74BT-04/PQ
✅ Drop-In✓ In Stock
$5.6 / Unit
View Datasheet →PIC16C74A-04/PQ
✅ Drop-In✓ In Stock
$5.8 / Unit
View Datasheet →PIC16C74AT-20I/PQ
✅ Drop-In✓ In Stock
$7.1 / Unit
View Datasheet →PIC16F74-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C74B-04/PQ Maximum Ratings & Electrical Characteristics
| Core | PIC16 mid-range 8-bit RISC |
| Instruction Set Size | 35 single-word instructions |
| Program Memory | 7 KB (4K x 14) OTP EPROM |
| RAM | 192 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Execution Time | 200 ns |
| Operating Voltage Range | 2.5 V to 6.0 V |
| Digital I/O Pins | 33 |
| A/D Converter | 8 channels x 8-bit |
| Timers | 3 (Timer0, Timer1, Timer2) |
| CCP Modules | 2 (Capture/Compare/PWM) |
| Serial Interfaces | SPI, I2C (MSSP), USART |
| I/O Sink/Source Current | 25 mA / 25 mA |
| Operating Current (5V, 4 MHz) | 15 µA typical |
| Standby Current (3V, 32 kHz) | 1 µA typical |
| Package | 44-pin MQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40C to +125C (Extended) |
PIC16C74B-04/PQ Pin Configuration
| Pin 1 | MCLR/VPP — Master clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / Analog input 3 / ADC reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / Read control / Analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / Write control / Analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / Chip select / Analog input 7 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground |
| Pin 13 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 output |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 20 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 21 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 22 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 23 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 29 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 30 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 31 | VSS — Ground |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3/PGM — PORTB bit 3 / Low-voltage programming |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 41 | NC — Not connected |
| Pin 42 | NC — Not connected |
| Pin 43 | NC — Not connected |
| Pin 44 | NC — Not connected |
Typical Applications
PIC16C74B-04/PQ is suitable for 6 applications: Industrial Process Control, Motor Drive and PWM Control, Sensor Signal Acquisition, Power Supply Monitoring and Control, Automotive Body Electronics (Legacy), Embedded Data Acquisition Systems.
Industrial Process Control
The PIC16C74B-04/PQ suits industrial process control with its 8-channel 8-bit ADC, which scans multiple analog inputs (temperature, pressure, flow) without an external multiplexer. The 33 digital I/O pins drive relays, solenoids, and indicator LEDs directly via 25 mA sink/source drive strength, eliminating external drivers. Its wide 2.5V-6.0V operating range accepts both regulated 5V logic rails and 24V industrial bus power after regulation. The 7 KB OTP memory holds process loop firmware and PID control tables, while the two CCP modules generate PWM outputs for valve and motor actuator control.
Recommended
Motor Drive and PWM Control
The PIC16C74B-04/PQ's two Capture/Compare/PWM modules generate complementary PWM outputs for DC motor, stepper, and small BLDC driver stages. With 4 MHz instruction rate and 200 ns cycle time, the MCU achieves 9-bit effective PWM resolution at 20 kHz switching frequency - adequate for brushed motor control and small fan speed regulation. The 25 mA I/O sink/source current directly drives opto-couplers and small gate drivers. Industrial temperature variants (PIC16C74B-04I/PQ) extend deployment to factory-floor enclosures with ambient temperatures above 70C.
Recommended
Sensor Signal Acquisition
The PIC16C74B-04/PQ's 8-channel 8-bit ADC samples sensor arrays in data acquisition front-ends, supporting thermistor, RTD bridge, and 4-20 mA current loop interfaces through external signal conditioning. The integrated USART streams converted data to a host controller at standard baud rates up to 115.2 kbps, while the MSSP (SPI/I2C) port reads digital sensors and EEPROM calibration tables. Low standby current of 1 µA at 3V makes the part attractive for battery-powered sensor transmitters that sleep between measurement cycles.
Recommended
Power Supply Monitoring and Control
The PIC16C74B-04/PQ monitors multi-rail power supplies by sampling output voltages with its 8-channel ADC and asserting digital control signals to enable/disable downstream converters. Its wide 2.5V-6.0V supply range allows direct connection to 3.3V or 5V auxiliary rails without level shifting. The USART reports telemetry to a system supervisor via UART, while the two CCP modules provide timing for sequencing power-up of multiple rails. Commercial/industrial temperature grades handle telecom and server-room ambient conditions.
Recommended
Automotive Body Electronics (Legacy)
The PIC16C74B-04/PQ appears in legacy automotive body modules (interior lighting, seat controllers, instrument cluster drivers) where the 33 I/O pins, 8 ADC channels, and CCP PWM outputs provide sufficient peripheral integration for a single-chip solution. The industrial temperature variant (-40C to +85C or extended -40C to +125C) handles cabin and under-hood thermal stress. While new automotive designs use Flash-based PIC16F or PIC18 families, the OTP PIC16C74B continues in long-life automotive aftermarket and replacement part channels.
Recommended
Embedded Data Acquisition Systems
The PIC16C74B-04/PQ forms the core of stand-alone data loggers that sample analog inputs, store measurements to external EEPROM via I2C, and transmit accumulated data over USART. The 192-byte RAM buffers sensor samples between ADC conversions, while the 7 KB OTP holds acquisition scheduling and on-the-fly calculations. With 4 MHz operation and 200 ns instruction time, the MCU sustains 8-channel ADC scans at several kHz aggregate rates, suitable for vibration monitoring, HVAC logging, and remote telemetry units.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74B-04/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74B-04I/PQ | PIC16C74BT-04/PQ | PIC16C74A-04/PQ | PIC16C74AT-20I/PQ | PIC16F74-I/PQ |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | MQFP-44 (10x10 mm) | MQFP-44 (10x10 mm) - same | MQFP-44 (10x10 mm) - same | MQFP-44 (10x10 mm) - same | MQFP-44 (10x10 mm) - same | MQFP-44 (10x10 mm) - same |
| Core | 8-bit PIC mid-range | 8-bit PIC mid-range | 8-bit PIC mid-range | 8-bit PIC mid-range | 8-bit PIC mid-range | 8-bit PIC mid-range |
| Maximum Clock | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz |
| Program Memory | 7 KB OTP EPROM | 7 KB OTP EPROM | 7 KB OTP EPROM | 7 KB OTP EPROM | 7 KB OTP EPROM | 7 KB Flash |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| ADC | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit |
| Operating Voltage | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.0 V to 6.0 V |
| Temperature Grade | Commercial (0C to +70C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Commercial (0C to +70C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) |
Key Differentiators
- Industrial temperature option in same MQFP-44 footprint (vs PIC16C74B-04/PQ vs PIC16C74B-04I/PQ)
- Flash reprogrammability for development (vs PIC16C74B-04/PQ vs PIC16F74-I/PQ)
- Higher clock speed option for faster execution (vs PIC16C74B-04/PQ vs PIC16C74AT-20I/PQ)
Design Notes
OTP EPROM memory can be programmed exactly once; a programming error permanently bricks the device. Microchip strongly recommends using the Flash-based PIC16F74 family for prototyping and only converting to PIC16C74B for locked production firmware. Always verify the loaded code via verify-readback before depopulating the programmer socket, and stock sufficient pre-programmed units because each engineering rework consumes a new part.
Place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pin pair (pins 11/12 and 31/32 on the MQFP-44). Add a 10 µF bulk capacitor at the board's power entry point. The 44-pin MQFP's fine 0.8 mm pitch requires IPC-A-610 Class 2 or 3 assembly with solder paste inspection (SPI) and automated optical inspection (AOI); reflow profile must stay below 250C peak with 60 s above 217C to avoid package delamination.
At 4 MHz with 15 µA typical operating current at 5V, the PIC16C74B-04/PQ dissipates only ~75 µW and requires no special thermal management. However, the 25 mA I/O sink/source current per pin (and 33 pins) can deliver up to 825 mA aggregate if all pins switch simultaneously - verify that the package's 1 W power dissipation limit is respected under worst-case load. For continuous high-current GPIO switching, distribute loads across multiple pins and consider external buffering.
Long parallel PORTD traces to external memory or PSP peripherals benefit from series damping resistors (22-33 ohm) near the MCU to suppress ringing. The MSSP (SPI/I2C) bus requires pull-up resistors on SCL/SDA per I2C specification; for 400 kHz Fast Mode, use 2.2-4.7 kohm pull-ups. Place the crystal oscillator load capacitors (typically 15-33 pF) within 2 mm of OSC1/OSC2 pins (13/14) with a grounded guard ring to attenuate EMI coupling into adjacent ADC channels.
Compliance Information
PIC16C74B-04/PQ is generally not lead-free / not RoHS compliant per legacy MQFP package with SnPb lead finish. Industrial-grade -04I variant and Flash-based PIC16F74 family offer RoHS-compliant lead-free options.
