PIC16C74A-20I/L - 8-Bit 20MHz OTP MCU 7KB | Microchip
MPN: PIC16C74A-20I/L ā Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $13.61 | $13.61 |
| 10 | $12.25 | $122.50 |
| 100 | $10.95 | $1,095.00 |
| 500 | $9.8 | $4,900.00 |
| 1,000 | $8.75 | $8,750.00 |
PIC16C74A-20I/L Overview
An 8-bit microcontroller (MCU) is a single-chip microcomputer containing a CPU, memory, and peripherals on one die, executing instructions on 8-bit data words. Within the broader taxonomy, the PIC16C74A belongs to the mid-range 8-bit MCU category, itself part of the microcontroller family of embedded processors within the semiconductor hierarchy. OTP memory permits one-time programming during production but cannot be erased afterwards; for erasable variants, Microchip recommends the PIC16F74 Flash-based equivalent.
Key features of the PIC16C74A-20I/L include high sink/source current of 25/25 mA per I/O, low-power consumption (5 ĀµA typical standby at 3V/32 kHz, 15 ĀµA at 5V/4 MHz), a high-performance RISC architecture with only 35 single-word instructions to learn, and all instructions execute in a single cycle except program branches (two cycles). The integrated peripherals include a synchronous serial port (SSP) for SPI/I2C, a USART for asynchronous serial communication, and a parallel slave port for external bus interfaces.
The device is built on a fully-static CMOS process, allowing clock frequencies from DC up to 20 MHz without internal oscillator overhead. The 8-bit A/D converter with 8 input channels enables direct interfacing with analog sensors, while the 192-byte RAM supports small data buffers for real-time control loops. OTP program memory provides cost-effective one-time programming suitable for mature production designs.
Typical applications include industrial control systems, automotive body electronics, appliance controllers, sensor signal conditioning nodes, and embedded data acquisition modules. The 33 I/O pins and integrated ADC make it particularly suitable for multi-channel sensor monitoring applications. When designing with the PIC16C74A-20I/L, verify MCLR reset circuitry and use a 1 ĀµF decoupling capacitor on VDD within 1 cm of the device; the OTP memory cannot be field-updated, so development should use the Flash-based PIC16F74 equivalent before committing to OTP production parts.
This page synthesizes distributor stock and pricing snapshots (as of 2026-09-18), drop-in compatible alternatives in the same 44-PLCC footprint, and practical design notes not found in the original 1997-vintage manufacturer datasheet.
Drop-in alternatives for PIC16C74A-20I/L ā 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-20I/L (same form factor and footprint) ā differing in Data EEPROM, I/O Sink/Source Current, Mounting Type, Package, Program Memory Type.
Quick Comparison Tool ā Select alternative parts for side-by-side comparison:
PIC16F74-I/L
ā Drop-Inš Reference alternative (not in catalog)
PIC16F74T-I/L
ā Drop-Inš Reference alternative (not in catalog)
PIC16C74B-20I/L
ā Drop-Inā In Stock
$8.92 / Unit
View Datasheet āPIC16C74A-20/L
ā Drop-Inš Reference alternative (not in catalog)
PIC16C74A-20I/L Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC RISC (mid-range) |
| Instruction Set | 35 single-word instructions |
| Maximum Clock Frequency | 20 MHz |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14) |
| Data RAM | 192 bytes |
| Data EEPROM | Not present on this OTP variant |
| Supply Voltage Range | 2.5 V to 6.0 V |
| I/O Pins | 33 |
| A/D Converter | 8 channels x 8-bit |
| Timer/Counters | 3 (with CCP) |
| Serial Interfaces | SSP (SPI/I2C), USART |
| Parallel Slave Port | Yes (8-bit) |
| I/O Sink/Source Current | 25 mA / 25 mA |
| Operating Temperature Range | -40 C to +85 C (Industrial, "I" grade) |
| Package | 44-pin PLCC (J-Lead) |
| Mounting Type | Surface Mount (PLCC socket compatible) |
PIC16C74A-20I/L 44-pin plcc (j-lead) Pin Configuration Guide
Pin configuration for PIC16C74A-20I/L (44-pin plcc (j-lead) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for PIC16C74A-20I/L.
Refer to the datasheet for full pin configuration.
Typical Applications
PIC16C74A-20I/L is suitable for 6 applications: Industrial Sensor Monitoring, Appliance Control Board, Automotive Body Electronics, Embedded Data Acquisition Module, Security and Access Control, Hobbyist and Educational Embedded Platform.
Industrial Sensor Monitoring
The PIC16C74A-20I/L's 8-channel 8-bit A/D converter and 33 digital I/O pins make it well-suited for multi-channel industrial sensor monitoring. It can directly sample 8 analog inputs (thermistors, pressure transducers, photo-sensors) while driving indicator LEDs, relays, and operator panel switches through its 25 mA sink/source capable ports. Operating from 2.5 V to 6.0 V at industrial temperatures (-40Ā°C to +85Ā°C), the device handles factory-floor environments without additional conditioning. Its 35-instruction RISC core and 20 MHz clock allow tight control loops for process regulation. The 192-byte RAM is adequate for sensor smoothing buffers. OTP memory ensures firmware stability in field-deployed industrial systems that rarely require code updates.
Recommended
Appliance Control Board
The PIC16C74A-20I/L fits appliance control applications such as washing machines, dishwashers, and HVAC controls where a stable OTP part is preferred for cost reasons. The 33 I/O lines interface directly with mechanical push-buttons, rotary encoders, seven-segment displays, and triac-driven AC loads. Three timer/counters with CCP support precise PWM for motor speed control and proportional valve actuation. The USART enables diagnostics communication with service tools. Operating at 5 V from a simple linear regulator and tolerating up to 6 V, the MCU coexists with noisy relay-driven power stages. OTP memory locks production firmware, preventing field corruption by voltage transients common in white-goods environments.
Recommended
Automotive Body Electronics
The PIC16C74A-20I/L's industrial temperature rating (-40Ā°C to +85Ā°C) and OTP one-time-programmable memory are useful for automotive body electronics such as mirror controllers, seat position modules, and lighting timers. Its 8-channel ADC reads potentiometers and current-sense amplifiers, while 33 I/O drive MOSFET gates, lamps, and H-bridges. The 20 MHz RISC core executes body-controller state machines efficiently, and the SSP supports SPI peripherals such as CAN-transceiver companion chips. Although Microchip's newer PIC16F family is preferred for AEC-Q100 designs, the PIC16C74A remains in production for cost-sensitive legacy body modules where OTP stability and 25 mA I/O drive eliminate external transistors.
Recommended
Embedded Data Acquisition Module
The PIC16C74A-20I/L serves as the CPU in standalone data-acquisition front-ends that log multi-channel analog signals to external EEPROM or SD cards. Its 8-bit successive-approximation ADC samples 8 channels with selectable references, while the SSP SPI port streams data to a serial Flash or SD card. The USART provides an RS-232 service-port for data retrieval and configuration. With 192 bytes of RAM, the MCU buffers acquisition frames before storage, and three timer/counters schedule precise sampling intervals. Operating at 5 V from a regulated supply, the device delivers reliable acquisition in instrumentation, environmental monitoring, and laboratory automation where OTP memory locks validated firmware.
Recommended
Security and Access Control
The PIC16C74A-20I/L is a practical choice for keypad door controllers, RFID readers, and simple alarm panels where 33 I/O lines interface with matrix keypads, magnetic-stripe readers, relay-controlled locks, and sirens. Its 20 MHz RISC core runs the access-control state machine fast enough for real-time PIN validation, while the 192-byte RAM holds the current credential being processed. The SSP/I2C port talks to EEPROM credential storage, and the USART connects to a central monitoring panel. OTP memory prevents firmware tampering ā important for security equipment where code-injection attacks must be impossible. Industrial temperature range permits outdoor mounting in secured enclosures.
Recommended
Hobbyist and Educational Embedded Platform
The PIC16C74A-20I/L is widely used in educational settings and hobbyist electronics projects, particularly with Microchip's MPLAB IDE and PICkit programmers. Its 35-instruction RISC architecture is the canonical teaching example for embedded programming courses, and the 7 KB OTP memory accommodates substantial student projects. The 44-PLCC package fits standard 44-pin PLCC sockets, simplifying breadboarding. With 33 I/O, 8-channel ADC, USART, SPI, I2C, three timers, and CCP PWM, students can implement UART communication, motor control, sensor acquisition, and interrupt-driven design all on one chip. The industrial temperature range allows robust student projects for outdoor demonstrations.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74A-20I/L ā comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F74-I/L | PIC16F74T-I/L | PIC16C74B-20I/L | PIC16C74A-20/L | PIC16C74A-20I/PQ |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-PLCC (J-Lead) | 44-PLCC (J-Lead) | 44-PLCC (J-Lead) | 44-PLCC (J-Lead) | 44-PLCC (J-Lead) | 44-MQFP (PQ) ā different footprint |
| Program Memory Type | OTP 7 KB | Flash 4 KB | Flash 4 KB | OTP 7 KB | OTP 7 KB | OTP 7 KB |
| Program Memory Size | 7 KB (4K x 14) | 4 KB | 4 KB | 7 KB (4K x 14) | 7 KB (4K x 14) | 7 KB (4K x 14) |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Voltage | 2.5 V to 6.0 V | 2.0 V to 6.0 V | 2.0 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 |
| Temperature Range | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) |
| 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 |
| Field Reprogrammable | No (OTP) | Yes (Flash) | Yes (Flash) | No (OTP) | No (OTP) | No (OTP) |
| Approx. Unit Price (USD, as of 2026-09-18) | 13.61 | Lower (Flash, higher volume) | Lower (Flash, tape & reel) | Similar to PIC16C74A | Similar (commercial grade) | Similar (MQFP variant) |
Key Differentiators
- Officially endorsed Flash-based successor with field updates (vs PIC16F74-I/L)
- Industrial temperature range and mature OTP stability (vs PIC16C74A-20/L)
- Direct drop-in silicon revision within OTP family (vs PIC16C74B-20I/L)
Design Notes
Place a 0.1 ĀµF ceramic decoupling capacitor within 1 cm of the VDD pin and a 10 ĀµF bulk capacitor near the MCU power pins to suppress switching noise. The PIC16C74A-20I/L has separate AVdd/AVss pins for the ADC; the analog supply must be filtered with a ferrite bead or small inductor and a dedicated 10 ĀµF + 0.1 ĀµF RC network to prevent digital switching noise from coupling into the ADC readings. Brown-out detection at 4.0 V (BOREN enabled) is recommended for unreliable supply rails to avoid corruption of the OTP program memory.
OTP program memory can be programmed only once; any bug in firmware becomes permanent. Always develop and validate on a PIC16F74-I/L (Flash, same footprint) before committing to PIC16C74A-20I/L for production. Watch the MCLR pin: floating or weak pull-up can cause intermittent resets ā use a 10 kĪ© pull-up to Vdd and a 100 nF capacitor to ground for stable operation. The 8-bit ADC's reference voltage pins (Vref+/Vref-) must be sourced from low-impedance drivers (ā¤10 Ī©) ā using Vdd as reference without buffering introduces 1-2 LSB of ADC error.
The 44-PLCC package should be socketed (e.g., 44-pin PLCC thru-hole or SMT socket) for prototype development, allowing easy swap between PIC16C74A-20I/L (OTP) and PIC16F74-I/L (Flash) during firmware validation. Place the ICSP programming header (Vpp, Vdd, GND, RB6/PGC, RB7/PGD) on a 0.1-inch pitch 5-pin header on the board edge for factory programming access. Keep the 20 MHz crystal traces short and symmetric, with load capacitors (typically 15-33 pF) returned to GND within 5 mm of the OSC1/OSC2 pins to avoid parasitic oscillation modes.
Compliance Information
RoHS and lead-free status confirmed via Microchip product page and distributor listings. The ICE product is not AEC-Q100 qualified; Microchip's newer PIC16F family typically carries automotive grade for body-electronics applications. Conflict-minerals compliance per Microchip corporate policy.
