PIC16C74A-04/P - 8-Bit 4MHz OTP MCU 7KB | Microchip
MPN: PIC16C74A-04/P β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.65 | $76.50 |
| 100 | $6.8 | $680.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.45 | $5,450.00 |
PIC16C74A-04/P Overview
What is an 8-bit OTP microcontroller? A microcontroller (MCU) is a single-chip computer containing a CPU, memory, and peripherals; the 8-bit designation means its data path and registers are 8 bits wide. OTP (One-Time-Programmable) memory can be written once and is ideal for low-to-mid volume production where flash reprogrammability is not required. Within the broader taxonomy, the PIC16C74A sits in the hierarchy: microcontroller -> embedded controller -> 8-bit MCU -> PIC mid-range -> PIC16C7X family. Mid-range PIC MCUs target low-cost, high-performance control applications with a RISC instruction set, integrated peripherals, and broad tool support.
Key differentiating features include 192 bytes of RAM, 33 digital I/O pins, an integrated 8-channel 8-bit A/D converter, two CCP modules, a USART, an MSSP (SPI/I2C), and three timers. The 'A' revision improved A/D accuracy and added the 8-bit A/D converter variant versus earlier PIC16C74 silicon, and the '-04' speed suffix denotes 4 MHz operation (vs. '-10' and '-20' variants at higher speeds). The device draws only 15 uA typical at 5 V/4 MHz and 1 uA standby at 3 V/32 kHz.
Technically, the PIC16C74A uses a Harvard architecture with separate program and data buses, a 14-bit instruction word, and a 35-instruction RISC set, all single-cycle except program branches (two cycles). The 40-pin PDIP package has 33 I/O, 5 capture analog inputs, and 2 power/ground pins. Operating voltage is 4.0 to 6.0 V, with industrial and commercial temperature grades available.
Typical applications include industrial control panels, motor control signal conditioning, sensor interfacing, simple HVAC controllers, automotive body electronics (pre-CAN nodes), and white-goods user interfaces where OTP cost advantages dominate over flash reprogramming.
When designing with the PIC16C74A-04/P, account for OTP programming - firmware must be 100% verified before programming since no field updates are possible. For development, use the PIC16C74A-04/JW (windowed CERDIP) or migrate to the PIC16F74 flash equivalent if in-system reprogrammability is required.
This page synthesizes distributor pricing, drop-in same-package alternatives, lifecycle context, and design considerations not aggregated on any single manufacturer or distributor page.
Drop-in alternatives for PIC16C74A-04/P 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 PIC16C74A-04/P (same form factor and footprint) β differing in Core Architecture, Operating Temperature, Package, Supply Voltage.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16F74-I/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74A-20/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74A-10/P
β Drop-Inβ In Stock
$4.65 / Unit
View Datasheet βPIC16C74B-04/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C76-04/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74A-04/P Maximum Ratings & Electrical Characteristics
| Product Family | PIC16C7X (mid-range 8-bit MCU) |
| Core Architecture | PIC RISC (Harvard) |
| Data Bus Width | 8 bit |
| Instruction Word | 14 bit |
| Max CPU Clock | 4 MHz |
| Program Memory (ROM) | 7 KB (4K x 14) OTP |
| RAM | 192 bytes |
| I/O Pins | 33 |
| A/D Converter | 8 channels, 8-bit |
| Timers | 3 (Timer0, Timer1, Timer2) |
| CCP Modules | 2 |
| Serial Interfaces | USART + MSSP (SPI/I2C) |
| Supply Voltage | 4.0 V to 6.0 V |
| Active Current (5V, 4MHz) | 15 uA typical |
| Standby Current (3V, 32kHz) | 1 uA typical |
| Package | 40-pin PDIP (600 mil) |
| Mounting Type | Through-Hole |
| Operating Temperature | 0C to +70C (commercial) |
| Instruction Set | 35 instructions, single-cycle (branches 2-cycle) |
PIC16C74A-04/P Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (reset) input / Programming voltage |
| Pin 2 | RA0/AN0 β Port A bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 β Port A bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2 β Port A bit 2 / Analog input 2 |
| Pin 5 | RA3/AN3/VREF β Port A bit 3 / Analog input 3 / A/D VREF |
| Pin 6 | RA4/T0CKI β Port A bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS β Port A bit 5 / Analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 β Port E bit 0 / Parallel slave port read / Analog input 5 |
| Pin 9 | RE1/WR/AN6 β Port E bit 1 / Parallel slave port write / Analog input 6 |
| Pin 10 | RE2/CS/AN7 β Port E bit 2 / Parallel slave port chip select / Analog input 7 |
| Pin 11 | VDD β Positive logic supply voltage (4.0V to 6.0V) |
| Pin 12 | VSS β Ground reference for logic and I/O pins |
| Pin 13 | OSC1/CLKIN β Oscillator crystal input / External clock input |
| Pin 14 | OSC2/CLKOUT β Oscillator crystal output / Clock output (Fosc/4) |
| Pin 15 | RC0/T1OSO/T1CKI β Port C bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 β Port C bit 1 / Timer1 oscillator input / CCP2 I/O |
| Pin 17 | RC2/CCP1 β Port C bit 2 / CCP1 I/O |
| Pin 18 | RC3/SCK/SCL β Port C bit 3 / MSSP SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 β Port D bit 0 / Parallel slave port data bit 0 |
| Pin 20 | RD1/PSP1 β Port D bit 1 / Parallel slave port data bit 1 |
| Pin 21 | RD2/PSP2 β Port D bit 2 / Parallel slave port data bit 2 |
| Pin 22 | RD3/PSP3 β Port D bit 3 / Parallel slave port data bit 3 |
| Pin 23 | RC4/SDI/SDA β Port C bit 4 / MSSP SPI data in / I2C data |
| Pin 24 | RC5/SDO β Port C bit 5 / MSSP SPI data out |
| Pin 25 | RC6/TX/CK β Port C bit 6 / USART async transmit / sync clock |
| Pin 26 | RC7/RX/DT β Port C bit 7 / USART async receive / sync data |
| Pin 27 | RD4/PSP4 β Port D bit 4 / Parallel slave port data bit 4 |
| Pin 28 | RD5/PSP5 β Port D bit 5 / Parallel slave port data bit 5 |
| Pin 29 | RD6/PSP6 β Port D bit 6 / Parallel slave port data bit 6 |
| Pin 30 | RD7/PSP7 β Port D bit 7 / Parallel slave port data bit 7 |
| Pin 31 | VSS β Ground reference |
| Pin 32 | VDD β Positive logic supply voltage |
| Pin 33 | RB0/INT β Port B bit 0 / External interrupt |
| Pin 34 | RB1 β Port B bit 1 |
| Pin 35 | RB2 β Port B bit 2 |
| Pin 36 | RB3/PGM β Port B bit 3 / Low-voltage programming |
| Pin 37 | RB4 β Port B bit 4 |
| Pin 38 | RB5 β Port B bit 5 |
| Pin 39 | RB6/PGC β Port B bit 6 / In-circuit debugger clock |
| Pin 40 | RB7/PGD β Port B bit 7 / In-circuit debugger data |
Typical Applications
PIC16C74A-04/P is suitable for 6 applications: Industrial Control Panel MCU, Motor Control Signal Conditioning, Sensor Interface and Data Acquisition Front-End, White-Goods User Interface Controller, Simple HVAC Zone Controller, Automotive Body Electronics Node (Pre-CAN).
Industrial Control Panel MCU
The PIC16C74A-04/P fits industrial control panels because its 33 I/O pins drive button matrices, LED indicators, relay coils, and 7-segment displays directly without external glue logic. The integrated 8-channel 8-bit A/D reads sensor inputs (temperature via thermistor bridge, pressure via strain gauge, position via potentiometer) at 4 MHz CPU clock with sufficient throughput for scan loops under 10 ms. The USART connects to operator panels and the MSSP talks to EEPROM/FRAM for parameter storage. Per Microchip reference designs, this 40-pin PDIP MCU is a drop-in for legacy panel retrofits. Trade-off: OTP means firmware changes require OTP swap; migrate to PIC16F74 for in-field updates.
Recommended
Motor Control Signal Conditioning
The PIC16C74A-04/P suits motor control signal conditioning because the two CCP modules generate PWM waveforms for H-bridge gate drivers while the 8-bit A/D samples back-EMF and current shunt signals at up to 8 channels. At 4 MHz CPU clock (1 MIPS), the interrupt latency is fast enough for current-loop control in brushed DC motors up to several kHz loop bandwidth. The 33 I/O pins handle direction logic, fault inputs, tachometer feedback, and brake commands without external logic. Per the PIC16C7X datasheet, the MSSP in SPI mode reads encoder ASICs. Trade-off: at higher RPM ranges or field-oriented control, step up to PIC16F74 or dsPIC for extra cycles.
Recommended
Sensor Interface and Data Acquisition Front-End
The PIC16C74A-04/P is well-matched to sensor front-ends because the 8-channel 8-bit A/D samples multiple analog sensors (temperature, humidity, light, pressure) sequentially with 4 MHz ADC clock, while the 192-byte RAM buffers conversion results before UART transmission. The 33 I/O pins switch sensor power via MOSFETs for low standby current. With 15 uA typical active current and 1 uA standby, the part suits battery-backed remote sensor nodes per the PIC16C7X datasheet. Trade-off: 8-bit A/D resolution limits precision - migrate to PIC16F877A (10-bit A/D) or PIC18F for higher accuracy.
Recommended
White-Goods User Interface Controller
The PIC16C74A-04/P drives white-goods user interfaces (washing machines, dishwashers, ovens) because the 33 I/O pins handle capacitive touch keys, rotary encoder inputs, 7-segment or LCD displays, buzzer PWM, and triac-fired heater control. The OTP memory locks in regulatory-approved firmware preventing field tampering, a key advantage for compliance-sensitive appliance markets. The two CCP modules generate zero-crossing triac triggers while the 8-bit A/D reads NTC temperature probes for closed-loop control. Per Microchip application notes, this 40-pin PDIP is widely deployed in legacy appliance designs. Trade-off: OTP cannot accept late firmware revisions - factor firmware freeze early.
Recommended
Simple HVAC Zone Controller
The PIC16C74A-04/P fits simple HVAC zone controllers because the 8-channel A/D reads multiple thermistor inputs for multi-zone temperature sensing, while the 33 I/O pins drive damper actuators, fan relays, and valve solenoids without external drivers. The 4 MHz CPU clock handles PID-style control loops at 100 ms sample rate for typical HVAC thermal mass. The MSSP I2C bus interfaces to wall-mounted temperature sensors and digital potentiometers for setpoint adjustment. Per PIC16C7X datasheet, the 4.0-6.0 V supply aligns with 5 V HVAC bus rails. Trade-off: zone count above 8 requires I/O expanders - plan MCP23017 in cascade.
Recommended
Automotive Body Electronics Node (Pre-CAN)
The PIC16C74A-04/P fits legacy automotive body nodes (window lifters, mirror adjusters, seat controllers) because the 33 I/O pins directly drive small DC motors and sense position switches, while the 8-bit A/D reads battery voltage for brownout detection. The USART provides LIN-bus communication for non-CAN body networks still common in older vehicle platforms. The 4 MHz clock avoids EMI issues in noisy automotive environments per the PIC16C7X datasheet. Trade-off: AEC-Q100 qualification is not stated for this OTP variant - for new automotive designs use PIC16F876A with explicit automotive grade.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74A-04/P β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F74-I/P | PIC16C74A-20/P | PIC16C74A-10/P | PIC16C74B-04/P | PIC16C76-04/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 40-pin PDIP - same | 40-pin PDIP - same | 40-pin PDIP - same | 40-pin PDIP - same | 40-pin PDIP - same | 40-pin PDIP - same |
| Program Memory | 7 KB OTP (4K x 14) | 7 KB Flash | 7 KB OTP | 7 KB OTP | 7 KB OTP | 8 KB OTP (4K x 14) |
| Max CPU Clock | 4 MHz | 20 MHz (flash variant) | 20 MHz | 10 MHz | 4 MHz | 4 MHz |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| A/D Converter | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit |
| Memory Type | OTP | Flash (rewriteable) | OTP | OTP | OTP | OTP |
| Unit Price (qty 100) | $6.80 | $7.50 (estimated, flash typically higher) | $9.50 (estimated) | $7.20 (estimated) | $7.80 (estimated) | $8.40 (estimated) |
Key Differentiators
- Flash reprogrammability via PIC16F74 successor (vs PIC16F74-I/P)
- 5x faster CPU clock option at same pinout (vs PIC16C74A-04/P vs PIC16C74A-20/P)
- Silicon B-revision refinements to A/D converter (vs PIC16C74B-04/P)
Design Notes
The PIC16C74A-04/P uses OTP (one-time-programmable) memory - firmware bugs cannot be field-corrected. Always verify firmware with the PIC16C74A-04/JW (windowed CERDIP) development part before OTP programming. Microchip recommends migrating to PIC16F74 (flash equivalent) for any new design where late firmware changes are possible. OTP also means production programming must include a verification step plus a known-good golden signature read.
Operating voltage is 4.0 V to 6.0 V per the PIC16C7X datasheet - operation below 4.0 V is out-of-spec and may cause brownouts or A/D inaccuracy. Use a low-dropout regulator such as LP2950 or MCP1700 to derive 5 V from higher bus voltages. Add a 100 nF ceramic decoupling cap close to each VDD pin (pins 11 and 32), plus a 10 uF bulk capacitor on the supply rail. Standby current is 1 uA typical at 3 V/32 kHz per datasheet, suitable for battery-backed operation.
Place the 4 MHz crystal or resonator close to OSC1 (pin 13) and OSC2 (pin 14) with short traces and a grounded guard ring. Keep high-current switching traces (CCP1/CCP2 PWM outputs, motor drive signals) away from the crystal traces and analog inputs (RA0-RA5, RE0-RE2). The A/D converter is sensitive to digital switching noise - per Microchip application notes, add a small RC filter (100 ohm + 100 nF) on each analog input when sampling low-level signals.
Estimated: the PIC16C74A-04/P in 40-pin PDIP has a theta_JA of approximately 50 C/W. At maximum active current of 15 mA at 5 V (75 mW) plus I/O drive, total dissipation is typically under 150 mW, yielding about 7.5 C junction rise - well within the 0C to +70C commercial range. No heatsink is required. However, if I/O pins source/sink high currents (25 mA per pin per datasheet), sum all I/O dissipation and verify junction stays below 125 C.
Compliance Information
PIC16C74A-04/P is a pre-2002 OTP part in 40-pin PDIP, generally not lead-free or RoHS compliant - verify with distributor for current RoHS exemption status. Not AEC-Q100 qualified; for automotive designs use PIC16F876A-I/SP or PIC18F automotive grade parts. Pin-compatible RoHS-compliant option: PIC16F74-I/P (flash).
