PIC16C74A-20/L - 8-Bit 20MHz OTP MCU 7KB | Microchip | PLCC-44
MPN: PIC16C74A-20/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.2 | $11.20 |
| 10 | $9.95 | $99.50 |
| 100 | $8.75 | $875.00 |
| 500 | $7.8 | $3,900.00 |
| 1,000 | $7.1 | $7,100.00 |
PIC16C74A-20/L Overview
A PIC microcontroller is a compact programmable processor based on a Harvard RISC architecture that separates program and data memory for deterministic, single-cycle instruction execution. PIC16C-series MCUs sit in the hierarchy: microcontroller -> 8-bit MCU -> embedded controller -> semiconductor. They are widely used in cost-sensitive embedded designs where deterministic timing, low power consumption, and easy programmability outweigh the need for large memory or modern peripherals.
Key features include 35 single-word instructions (all single-cycle except two-cycle program branches), high sink/source current capability of 25 mA/25 mA per pin suitable for direct LED or relay drive, integrated analog peripherals, and three hardware timer/counter modules. The PIC16C74A-20/L also provides a USART, MSSP (SPI/I2C) port, 8-channel 8-bit ADC, capture/compare/PWM modules, and a programmable brown-out reset.
The PIC16C74A architecture uses an 8-level deep hardware stack and separate instruction/data buses. The OTP program memory is one-time programmable - once written it cannot be erased, distinguishing it from UV-erasable CERDIP variants in the family. Power consumption is exceptionally low: 15 uA typical at 5 V / 4 MHz and 1 uA typical standby at 3 V / 32 kHz.
Typical applications include industrial control logic, appliance controllers, automotive subsystems, sensor signal conditioning front-ends, and low-cost embedded products. The wide operating voltage range (2.5 V-6.0 V per family datasheet) and broad temperature grades make it suitable for both commercial and extended-environment designs.
When designing with this part, note that OTP memory cannot be re-programmed - use the CERDIP/JW windowed variant for prototype development. The A newer Flash-based PIC16F74 is pin-compatible and recommended for new designs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C74A-20/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 PIC16C74A-20/L (same form factor and footprint) — differing in Mounting Type, Data EEPROM, Package, Core Architecture, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F74-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C74B-20/L
✅ Drop-In✓ In Stock
$8.2 / Unit
View Datasheet →PIC16C74A-20I/L
✅ Drop-In✓ In Stock
$8.75 / Unit
View Datasheet →PIC16C74A-10/L
✅ Drop-In✓ In Stock
$8.4 / Unit
View Datasheet →PIC16C74A-04I/P
✅ Drop-In✓ In Stock
$7.5 / Unit
View Datasheet →PIC16C74A-20/L Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC16C RISC (Harvard) |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14) |
| RAM Size | 192 bytes |
| Data EEPROM | None (external emulation not supported) |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns (4 clock cycles per instruction) |
| Supply Voltage | 4.0 V to 5.5 V |
| Operating Temperature Range | 0C to +70C (Commercial, per /L suffix) |
| I/O Pins | 33 |
| Package | 44-pin PLCC (J-Lead), 16.59 x 16.59 mm |
| Mounting Type | Surface Mount |
| Timers | 3 (Timer0, Timer1, Timer2) |
| ADC | 8-channel, 8-bit |
| Communication Peripherals | USART (SCI), MSSP (SPI / I2C) |
| PWM Modules | 2 (CCP1, CCP2) |
| I/O Sink/Source Current | 25 mA / 25 mA per pin |
| Active Current (5 V / 4 MHz) | 15 uA typical |
| Standby Current (3 V / 32 kHz) | 1 uA typical |
| Instruction Set Size | 35 single-word instructions |
| Hardware Stack Depth | 8 levels |
| Watchdog Timer | Yes |
| Brown-out Reset | Programmable |
PIC16C74A-20/L Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (Reset) input / Programming voltage input |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / Analog input channel 3 / ADC voltage reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input 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 bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / CCP1 output |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK — PORTC bit 6 / USART asynchronous transmit / synchronous clock |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / USART asynchronous receive / synchronous data |
| Pin 18 | VSS — Ground reference |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (4.0 V to 5.5 V) |
| Pin 21 | VDD — Positive supply voltage (4.0 V to 5.5 V) |
| Pin 22 | RB0/INT — PORTB bit 0 / External interrupt input |
| Pin 23 | RB1 — PORTB bit 1 |
| Pin 24 | RB2 — PORTB bit 2 |
| Pin 25 | RB3 — PORTB bit 3 |
| Pin 26 | RB4 — PORTB bit 4 |
| Pin 27 | RB5 — PORTB bit 5 |
| Pin 28 | RB6/PGC — PORTB bit 6 / ICSP clock input |
| Pin 29 | RB7/PGD — PORTB bit 7 / ICSP data input/output |
| Pin 30 | VSS — Ground reference |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage (4.0 V to 5.5 V) |
| Pin 33 | VDD — Positive supply voltage (4.0 V to 5.5 V) |
| Pin 34 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port data bit 0 |
| Pin 35 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port data bit 1 |
| Pin 36 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port data bit 2 |
| Pin 37 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port data bit 3 |
| Pin 38 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port data bit 4 |
| Pin 39 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port data bit 5 |
| Pin 40 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port data bit 6 |
| Pin 41 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port data bit 7 |
| Pin 42 | VSS — Ground reference |
| Pin 43 | RE0/RD — PORTE bit 0 / Parallel Slave Port read control |
| Pin 44 | RE1/WR — PORTE bit 1 / Parallel Slave Port write control |
Typical Applications
PIC16C74A-20/L is suitable for 6 applications: Industrial Control Logic, Appliance Controllers, Automotive Body Electronics, Sensor Signal Conditioning, Consumer Electronics Embedded Control, Educational and Development Platforms.
Industrial Control Logic
The PIC16C74A-20/L is well-suited for industrial control logic applications such as motor controllers, conveyor sequencing, and PLC front-end logic. Its 20 MHz instruction cycle delivers 200 ns deterministic response times required for real-time control loops, while the 8-channel 8-bit ADC provides integrated sensor signal acquisition without external components. The 25 mA sink/source I/O capability can directly drive relays, solenoids, and opto-isolators - eliminating external driver stages. The wide 4.0-5.5 V supply range tolerates noisy industrial 24V-derived rails after regulation, and the 33 I/O pins accommodate multi-axis machines or sensor arrays. Brown-out reset and watchdog timer provide fault recovery needed for unattended factory installations. Drop-in compatibility with PIC16F74-I/L enables migration to flash memory when in-circuit firmware updates become necessary for deployed equipment.
Recommended
Appliance Controllers
The PIC16C74A-20/L serves as an effective controller in home appliances such as washing machines, dishwashers, microwave ovens, and HVAC zone controllers. Its low power consumption (15 uA active at 5V/4 MHz, 1 uA standby) enables energy-efficient designs meeting Energy Star requirements. The integrated USART supports communication with display modules and external sensors, while the MSSP peripheral handles I2C EEPROM storage for user settings. The 2 CCP/PWM modules can directly drive brushless DC motor control signals or TRIAC phase-angle dimming circuits. The 192 bytes RAM accommodates real-time operating system kernels managing user interface, sensor sampling, and actuator drive concurrently. OTP memory suits high-volume appliance production where firmware is finalized and per-unit programming cost matters more than field updates.
Recommended
Automotive Body Electronics
The PIC16C74A-20/L targets automotive body electronics subsystems including seat controllers, mirror positioners, window lift modules, and lighting controllers. The wide operating voltage tolerance and built-in brown-out reset handle automotive load-dump transients and cold-crank events common on 12V vehicle buses. The 8-bit ADC monitors battery voltage, current sense, and position feedback from potentiometers without external converters. PWM outputs drive LED tail-light brightness control or proportional valve actuation. The 25 mA I/O drives automotive-grade relays directly, simplifying BOM. Industrial temperature grade (-40C to +85C) variants like PIC16C74A-20I/L meet under-hood and cabin thermal requirements. The 33 I/O pins handle multi-channel sensor inputs (door switches, position sensors) plus multi-output actuator drive within a single MCU, reducing ECU count and harness complexity.
Recommended
Sensor Signal Conditioning
The PIC16C74A-20/L is used as a smart sensor front-end conditioning unit for thermocouples, RTDs, strain gauges, pressure transducers, and flow meters. The 8-channel 8-bit ADC with multiplexed inputs scans multiple sensor types in sequence, while CCP modules generate excitation signals for bridge sensors. The integrated USART streams processed data to a host controller over RS-232/RS-485, eliminating the need for external signal conditioning ASICs. The 35-instruction RISC architecture executes linearization algorithms (Steinhart-Hart for thermistors, polynomial compensation for thermocouples) with deterministic cycle counts - critical for real-time process control loops. Low standby current (1 uA at 3V/32 kHz) enables battery-powered wireless sensor nodes with multi-year lifetime. The 20 MHz clock achieves adequate oversampling for 12-bit equivalent effective resolution after averaging.
Recommended
Consumer Electronics Embedded Control
The PIC16C74A-20/L serves as a cost-effective control MCU in consumer electronics such as remote-controlled toys, electronic learning aids, fitness equipment, and small kitchen appliances. The OTP memory suits high-volume products where per-unit firmware is locked at production and the lowest possible unit cost is mandatory. The RISC architecture's deterministic 200 ns instruction execution at 20 MHz provides responsive user-interface handling without jitter. The integrated 8-bit ADC reads potentiometers, light sensors, and battery monitoring without external components. The 192-byte RAM hosts simple state machines and menu navigation buffers. PWM outputs drive motor speed control, LED brightness, or audio tone generation. Hardware peripherals (USART, I2C/SPI) allow connection to LCD displays, audio DACs, or wireless modules for connected consumer products. Industrial temp variants support outdoor fitness and garden equipment.
Recommended
Educational and Development Platforms
The PIC16C74A-20/L (and its PIC16C74B-20/L successor) is used in university embedded systems courses and professional development training to teach microcontroller fundamentals. The 44-pin PLCC package fits standard IC sockets in training kits and breadboard adapters, simplifying lab exercises. The 35-instruction RISC ISA is approachable for first-time embedded programmers - all single-cycle except program branches, allowing students to count clock cycles accurately. OTP memory in commercial demonstration units forces students to verify code thoroughly before programming, building good engineering discipline. The complete PIC16C7X family datasheet (document 30412D) provides extensive register-level documentation and assembly examples suitable for textbook study. Migration to PIC16F74-I/L with flash memory allows iterative lab development, making these parts ideal for teaching both legacy OTP concepts and modern flash-based MCU design.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74A-20/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F74-I/L | PIC16C74B-20/L | PIC16C74A-20I/L | PIC16C74A-10/L | PIC16C74A-04I/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | PLCC-44 (J-Lead) | PLCC-44 (J-Lead) - same | PLCC-44 (J-Lead) - same | PLCC-44 (J-Lead) - same | PLCC-44 (J-Lead) - same | PLCC-44 (J-Lead) - same |
| Program Memory Type | OTP EPROM (7 KB) | Flash (7 KB, 1000+ erase cycles) | OTP EPROM (7 KB) | OTP EPROM (7 KB) | OTP EPROM (7 KB) | OTP EPROM (7 KB) |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 10 MHz | 4 MHz |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| ADC Channels | 8 channels, 8-bit | 8 channels, 8-bit | 8 channels, 8-bit | 8 channels, 8-bit | 8 channels, 8-bit | 8 channels, 8-bit |
| Operating Temperature | 0C to +70C (Commercial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) |
| Recommended Status | NRND (use PIC16F74) | Active (recommended replacement) | NRND | NRND | NRND | NRND |
Key Differentiators
- Manufacturer-recommended flash replacement available with identical pinout (vs PIC16F74-I/L)
- Improved silicon revision with bug fixes (vs PIC16C74B-20/L)
- Industrial temperature range variant for harsh environments (vs PIC16C74A-20I/L)
- Lower clock grade variants available for power-sensitive designs (vs PIC16C74A-10/L)
Design Notes
Decouple VDD pins (4 of them on PLCC-44: pins 20, 21, 32, 33) with 100 nF ceramic capacitors placed as close as possible to the package - each VDD pin requires its own decoupling capacitor, plus a bulk 10 uF tantalum or aluminum electrolytic at the regulator output. The four VSS pins (18, 19, 30, 31, 42) must all be connected to ground to provide adequate current return paths and reduce ground bounce during high-current I/O switching (25 mA sink/source).
OTP EPROM memory cannot be erased or re-programmed - once you write a bad firmware image to PIC16C74A-20/L, that device is bricked. For development and prototype work, use the CERDIP (windowed) variant PIC16C74A-20/JW with UV-erasable EPROM, or migrate to the flash-based PIC16F74-I/L which is pin-compatible and supports in-circuit reprogramming via ICSP. Never attempt to program production units until firmware has been fully validated on JW-windowed or PIC16F74 parts.
The PLCC-44 package requires a socket for prototype work and field serviceability - solder directly to PCB only for high-volume production where field replacement is not anticipated. Keep the crystal/oscillator traces short (under 10 mm) and surround with a ground guard ring to reduce EMI susceptibility. The MCLR/VPP pin (pin 1) should have a 10-100 kohm pull-up to VDD and a 100 nF cap to ground for proper reset behavior; do not leave MCLR floating as it can cause spurious resets or program-mode entry.
Estimated: at maximum operating frequency of 20 MHz with all I/O pins sourcing 25 mA simultaneously, the PIC16C74A-20/L can dissipate up to approximately 400-500 mW in PLCC-44 (theta_JA typically ~50 C/W for PLCC packages), yielding a junction temperature rise of 25C above ambient at room temperature. For sealed enclosures without airflow, derate I/O drive strength or limit concurrent active I/O to maintain junction temperature below 125C maximum rating.
Compliance Information
PIC16C74A is NRND. RoHS/REACH/lead-free status not explicitly confirmed in verified web data; check Microchip product page for current compliance documentation. Industrial -40C to +85C variants (PIC16C74A-20I/L) are available but not AEC-Q100 qualified.