PIC16C642-04I/SP - 8-bit OTP MCU, 7KB EPROM, 22 I/O | Microchip
MPN: PIC16C642-04I/SP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.2 | $7.20 |
| 10 | $6.55 | $65.50 |
| 100 | $5.95 | $595.00 |
| 500 | $5.4 | $2,700.00 |
| 1,000 | $4.95 | $4,950.00 |
PIC16C642-04I/SP Overview
What is an OTP 8-bit microcontroller? An OTP microcontroller is a class of embedded controller that uses one-time-programmable EPROM to store firmware, offering a low-cost path for volume production after prototype validation. Microcontrollers of this type sit at the bottom of the embedded hierarchy: MCU -> 8-bit MCU -> CMOS MCU -> EPROM/OTP MCU -> peripheral-rich industrial controller. The PIC16C642 family is part of the PIC16C6x mid-range series, integrating the CPU, EPROM program store, RAM data memory, timers, comparators, and a programmable voltage reference in a single chip.
Key features include 7 KB (4K x 14) of program memory, 176 bytes of data RAM, 22 I/O pins, one 8-bit Timer/Counter with an 8-bit programmable prescaler, two analog comparators with a programmable on-chip voltage reference, and a watchdog timer for reliable unattended operation. The device is specified across the industrial temperature range of -40 °C to +85 °C and supports a maximum clock of 4 MHz (the "04" speed suffix), giving a 1 µs instruction cycle. Brown-out detection and power-on reset are provided for robust embedded behavior.
Typical applications include industrial control systems, appliance controls, security and alarm panels, instrumentation front-ends, automotive body electronics (non-safety), and educational development platforms where a windowed/UV-erasable or OTP variant is acceptable for cost reasons. The two on-chip comparators make the part especially suitable for analog signal conditioning and threshold detection without an external op-amp.
When designing with the PIC16C642-04I/SP, ensure that the oscillator configuration matches the application - the '04' suffix limits the device to a 4 MHz max clock. Because the SP package is through-hole SPDIP-28, it is preferred for prototype, hobby, and educational environments where DIP sockets simplify rework; consider the SOIC or windowed ceramic variants for surface-mount production or development/programming cycles.
Drop-in alternatives for PIC16C642-04I/SP — 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 PIC16C642-04I/SP (same form factor and footprint) — differing in Program Memory Type, Program Memory Size, Instruction Cycle Time, Operating Temperature, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C642-04E/SP
✅ Drop-In✓ In Stock
$5.65 / Unit
View Datasheet →PIC16C642-04/SO
✅ Drop-In✓ In Stock
$4.3 / Unit
View Datasheet →PIC16C622-04/P
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.55 / Unit
View Datasheet →PIC16C621-04I/P
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$1.38 / Unit
View Datasheet →PIC16C620A-04I/P
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C642-04I/SP Maximum Ratings & Electrical Characteristics
| Program Memory Type | OTP EPROM |
| Program Memory Size | 7 KB (4K x 14) |
| Data RAM | 176 bytes |
| I/O Pins | 22 |
| CPU Architecture | 8-bit PIC RISC |
| Instruction Set | 35 single-word instructions |
| Max Clock Frequency | 4 MHz |
| Instruction Cycle Time | 1 µs (200 ns for internal branches) |
| Supply Voltage (Vdd) | 4 V to 5.5 V |
| Operating Temperature | -40 °C to +85 °C (Industrial) |
| Package | SPDIP-28 (Skinny Plastic DIP, 0.300 inch) |
| Mounting Type | Through-Hole |
| Timers | 1 x 8-bit Timer/Counter with 8-bit prescaler |
| Analog Comparators | 2 with programmable on-chip voltage reference |
| Watchdog Timer | Yes |
| Brown-out Reset / Power-on Reset | Yes |
| Speed Grade Suffix | 04 (4 MHz max) |
PIC16C642-04I/SP 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 — PORTA bit 3 / Analog input 3 |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/SS — PORTA bit 5 / Synchronous Serial port select |
| Pin 8 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 9 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 10 | RC0 — PORTC bit 0 |
| Pin 11 | RC1 — PORTC bit 1 |
| Pin 12 | RC2 — PORTC bit 2 |
| Pin 13 | RC3 — PORTC bit 3 |
| Pin 14 | RC4 — PORTC bit 4 |
| Pin 15 | RC5 — PORTC bit 5 |
| Pin 16 | RC6 — PORTC bit 6 |
| Pin 17 | RC7 — PORTC bit 7 |
| Pin 18 | RB0/INT — PORTB bit 0 / External interrupt input |
| Pin 19 | Vss — Ground reference |
| Pin 20 | VDD — Positive supply voltage |
| Pin 21 | RB1 — PORTB bit 1 |
| Pin 22 | RB2 — PORTB bit 2 |
| Pin 23 | RB3 — PORTB bit 3 |
| Pin 24 | RB4 — PORTB bit 4 |
| Pin 25 | RB5 — PORTB bit 5 |
| Pin 26 | RB6 — PORTB bit 6 |
| Pin 27 | RB7 — PORTB bit 7 |
| Pin 28 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C642-04I/SP is suitable for 7 applications: Industrial Control Systems, Appliance Control (Washers, Ovens, HVAC), Security and Alarm Panels, Instrumentation Front-Ends, Automotive Body Electronics (Non-Safety), Educational and Hobby Development, LED Lighting and Display Drivers.
Industrial Control Systems
The PIC16C642-04I/SP fits industrial control applications where its 22 I/O pins handle sensor inputs, relay drivers, and HMI buttons. The two on-chip analog comparators with programmable voltage reference enable direct threshold detection on process variables without external op-amps, while the watchdog timer and brown-out reset ensure reliable unattended operation on factory floors. Industrial-grade -40 to +85 C temperature range supports deployment in enclosures with elevated ambient temperatures. Pin-compatible variants in the PIC16C62x/64x family allow firmware upgrades within the same PCB footprint as system requirements evolve.
Recommended
Appliance Control (Washers, Ovens, HVAC)
White-goods controllers benefit from the PIC16C642-04I/SP's combination of 22 I/O lines for keypad scanning, LED/relay drivers, and triac interfaces. The 4 MHz core executes control-loop firmware at 1 µs per instruction, easily handling PID temperature regulation for ovens and motor speed sequencing for washing machines. Brown-out reset and the watchdog timer protect against supply glitches during compressor inrush, while the on-chip voltage reference simplifies sensor-bridge excitation for thermistor/RTD inputs.
Recommended
Security and Alarm Panels
The PIC16C642-04I/SP's 22 I/O and two analog comparators support multi-zone security panels: each zone input can be routed through an on-chip comparator for window/door-loop threshold detection without external circuitry. The 7 KB OTP EPROM holds arm/disarm state machines and communication protocol stacks. Industrial temperature range ensures operation in unheated garages and basements, while the watchdog timer recovers the system from lockup caused by EMI transients from siren drivers.
Recommended
Instrumentation Front-Ends
Bench instruments and data-loggers benefit from the PIC16C642-04I/SP's two comparators and programmable voltage reference for threshold and window-detection on analog channels. The 22 I/O pins drive LCD segment controls, push-button menus, and RS-232 level shifters. The 176-byte RAM buffers measurement samples before UART transmission, while the 4 MHz instruction rate (1 µs) gives ample margin for software UART at 9600 baud. Through-hole SPDIP packaging supports hand-soldered prototype builds common in lab instrumentation.
Recommended
Automotive Body Electronics (Non-Safety)
Body-control accessories such as seat controllers, mirror adjusters, and interior lighting modules can use the PIC16C642-04I/SP in non-safety automotive applications. The two analog comparators detect current-sense thresholds for short-circuit protection on lamp drivers, while the 22 I/O drive multiple MOSFET half-bridges. Industrial temperature grade handles cabin environments reliably. For under-hood safety-critical functions, migrate to a Q100-qualified PIC18 or dsPIC part instead.
Recommended
Educational and Hobby Development
The PIC16C642-04I/SP's DIP-28 package is breadboard-friendly and pairs naturally with Microchip's PICStart Plus or MPLAB PM3 programmers for student projects. The 35-instruction RISC architecture is approachable for learners, while the 7 KB EPROM holds substantial textbook-style projects (digital thermometer, stopwatch, IR remote decoder). The two on-chip comparators let students explore analog signal conditioning without external op-amps, building intuition for mixed-signal design that transfers to later PIC16F/PIC18 platforms.
Recommended
LED Lighting and Display Drivers
The PIC16C642-04I/SP can drive LED matrix displays and decorative lighting strips via PWM-like bit-banging on its 22 I/O pins, while the on-chip timer/counter with 8-bit prescaler generates precise refresh intervals. The two comparators sense current-sense amplifier outputs for shorted-LED protection. Industrial temperature range supports outdoor signage enclosures. For new designs requiring higher PWM resolution and lower power, consider the flash-based PIC16F887-I/P migration path with hardware PWM modules.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C642-04I/SP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C642-04E/SP | PIC16C642-04/SO | PIC16C622-04/P | PIC16C621-04I/P | PIC16C620A-04I/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SPDIP-28 | SPDIP-28 - same | SPDIP-28 (same body, but commercial temp grade) | SPDIP-28 - same | SPDIP-28 - same | SPDIP-28 - same |
| Program Memory (KB) | 7 KB (4K x 14) OTP EPROM | 7 KB (same die) | 7 KB (same die) | 3.5 KB | 1.75 KB | 0.875 KB |
| Data RAM (bytes) | 176 | 176 | 176 | 128 | 80 | 96 |
| I/O Pins | 22 | 22 | 22 | 22 | 13 | 13 |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) |
| Analog Comparators | 2 with Vref | 2 with Vref | 2 with Vref | 2 with Vref | 1 | 1 |
Key Differentiators
- Largest program memory in the PIC16C64x sibling family (vs PIC16C641)
- Two on-chip comparators with programmable Vref (vs PIC16C621-04I/P)
- 176 bytes of RAM for buffering (vs PIC16C622-04/P)
Design Notes
Place a 0.1 µF decoupling capacitor as close as possible to the Vdd pin (pin 20) of the PIC16C642-04I/SP, with a short trace to Vss (pin 19). For designs with high-current peripheral switching (relays, solenoids), add a bulk 10 µF electrolytic or tantalum capacitor on the main 5 V rail to absorb inrush current. Microchip's PIC16C64X datasheet recommends a low-ESR bypass within 5 mm of the supply pins to prevent EPROM read errors caused by Vdd droop during code execution.
The '04' suffix limits the PIC16C642-04I/SP to 4 MHz maximum clock input. When using a crystal oscillator, select a fundamental-mode 4 MHz crystal with appropriate load capacitors (typically 15-33 pF on each leg of OSC1/OSC2). Do not use overtone crystals - the internal oscillator amplifier is designed for fundamental-mode operation. For noisy environments, prefer the HS (high-speed) oscillator mode above 4 MHz parts rather than the LP mode to maximize noise immunity.
Keep the MCLR/Vpp pin (pin 1) trace short and avoid routing noisy digital signals nearby, because this pin is sensitive to fast-edge noise that could trigger spurious resets. Microchip recommends a 10 kΩ pull-up on MCLR tied to Vdd, with an optional 100 nF cap to ground for noise immunity. For ICSP (in-circuit serial programming), bring Vpp, RB6 (PGC) and RB7 (PGD) to an in-line header to allow MPLAB PM3 / PICkit 3 programming without removing the MCU from the board.
Do not exceed the absolute maximum Vdd of 7.0 V on the PIC16C642-04I/SP, and never apply voltage to MCLR/Vpp above 13.5 V or EPROM programming will fail. The 4 MHz speed grade cannot be overclocked - attempting to drive OSC1 with a 10 MHz or 20 MHz signal will produce timing violations and unreliable EPROM reads. Finally, OTP parts cannot be reprogrammed, so plan for a UV-erasable windowed variant (e.g., PIC16C642-04/JW) during firmware development cycles.
Compliance Information
RoHS and lead-free status not stated in the provided web data; the SPDIP-28 industrial temp grade is generally not RoHS in original Microchip ordering codes (typical lead finish). AEC-Q100 not qualified - this part targets industrial, not automotive safety applications. Conflict-mineral statement assumed compliant per Microchip standard policy.
