PIC16C642-04I/SO - 8-Bit 4MHz OTP MCU, 7KB, 22 I/O | Microchip
MPN: PIC16C642-04I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.78 | $6.78 |
| 10 | $6.1 | $61.00 |
| 100 | $5.42 | $542.00 |
| 500 | $4.75 | $2,375.00 |
| 1,000 | $4.07 | $4,070.00 |
PIC16C642-04I/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, non-volatile program memory, and peripheral I/O on a single die. Within the broader semiconductor taxonomy, the PIC16C642 sits at: microcontroller -> 8-bit MCU -> PIC16C family -> CMOS OTP microcontroller -> embedded processor. It belongs to the legacy PIC16C OTP (One-Time Programmable) EPROM-based series, which was succeeded by the flash-based PIC16F family but remains in production for long-life-cycle industrial equipment.
Key features include an operating voltage range of 4V to 6V, two analog comparators, a programmable code protection bit, power-on reset (POR), power-up timer (PWRT), oscillator start-up timer (OST), and a watchdog timer with its own on-chip RC oscillator for reliable operation. The device offers up to 20 MHz operation (10 MHz at this -04 speed grade), 200 ns instruction cycle, and all 35 instructions are single-word/single-cycle except program branches which take two cycles. The wide operating temperature range (-40C to +85C industrial grade) makes it suitable for harsh environments.
The PIC16C642 is built on Microchip's proven PIC Harvard-architecture RISC core, with separate program and data buses enabling simultaneous instruction fetch and operand access. Its CMOS EPROM cell provides non-volatile code storage, with OTP variants (such as this -04I/SO) intended for volume production where code is finalized. The 22 I/O pins can be individually configured as inputs or outputs, with high-current sink/source capability for direct LED drive.
Typical applications include industrial control systems, appliance controls, security and alarm panels, automotive body electronics, sensor interfaces, low-power remote sensors, and consumer electronics requiring deterministic real-time response. The two on-chip analog comparators are particularly useful for battery monitoring, threshold detection, and zero-crossing detection without external components.
When designing with this device, ensure the external oscillator or crystal is properly selected for the 4 MHz target frequency. Note that OTP parts cannot be reprogrammed, so code must be fully verified before programming. For new designs, consider the flash-based PIC16F family (such as PIC16F630 or PIC16F676) for in-circuit reprogrammability and broader tool support.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, providing a complete sourcing reference for procurement and design engineers evaluating legacy 8-bit MCU options.
Drop-in alternatives for PIC16C642-04I/SO — 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/SO (same form factor and footprint) — differing in Program Memory Type, Package, Core Architecture, Program Memory Size, Instruction Cycle Time.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C642-04/SO
✅ Drop-In✓ In Stock
$4.3 / Unit
View Datasheet →PIC16C642-04E/SP
✅ Drop-In✓ In Stock
$5.65 / Unit
View Datasheet →PIC16C642-04I/SP
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$4.95 / Unit
View Datasheet →PIC16C642-04I/SO Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Size | 8-Bit |
| Clock Speed (this -04 grade) | 4 MHz |
| Maximum Clock Speed (family) | 20 MHz |
| Instruction Execution Time | 200 ns (single cycle) |
| Number of Instructions | 35 single-word |
| Program Memory Type | OTP (EPROM) |
| Program Memory Size | 7 KB (4K x 14) |
| RAM Size | 176 bytes |
| EEPROM Size | None |
| Number of I/O Pins | 22 |
| Supply Voltage (Vcc/Vdd) | 4 V to 6 V |
| Analog Comparators | 2 (on-chip) |
| Operating Temperature | -40C to +85C (Industrial) |
| Package Type | 28-SOIC (0.295", 7.50 mm width) |
| Mounting Type | Surface Mount |
| Oscillator Type | External |
| Data Converters (ADC) | None |
PIC16C642-04I/SO Pin Configuration
| Pin 1 | RA2/AN2 — Port A bit 2 (bidirectional I/O, analog input) |
| Pin 2 | RA3/AN3 — Port A bit 3 (bidirectional I/O, analog input) |
| Pin 3 | RA4/T0CKI — Port A bit 4 (bidirectional I/O, Timer0 clock input) |
| Pin 4 | RA5/SS/AN4 — Port A bit 5 (bidirectional I/O, slave select, analog input) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Port B bit 0 (bidirectional I/O, external interrupt) |
| Pin 7 | RB1 — Port B bit 1 (bidirectional I/O) |
| Pin 8 | RB2 — Port B bit 2 (bidirectional I/O) |
| Pin 9 | RB3 — Port B bit 3 (bidirectional I/O) |
| Pin 10 | RB4 — Port B bit 4 (bidirectional I/O, interrupt-on-change) |
| Pin 11 | RB5 — Port B bit 5 (bidirectional I/O, interrupt-on-change) |
| Pin 12 | RB6 — Port B bit 6 (bidirectional I/O, interrupt-on-change, in-circuit programming clock) |
| Pin 13 | RB7 — Port B bit 7 (bidirectional I/O, interrupt-on-change, in-circuit programming data) |
| Pin 14 | VSS — Ground reference |
| Pin 15 | RC0 — Port C bit 0 (bidirectional I/O) |
| Pin 16 | RC1 — Port C bit 1 (bidirectional I/O) |
| Pin 17 | RC2 — Port C bit 2 (bidirectional I/O) |
| Pin 18 | RC3 — Port C bit 3 (bidirectional I/O) |
| Pin 19 | RD0 — [DATA_NEEDED: per-package pin mapping - 28-SOIC variant uses RC0-RC7 mapping above] |
| Pin 20 | VDD — Positive supply voltage (4V to 6V) |
| Pin 21 | VSS — Ground reference |
| Pin 22 | RC4 — Port C bit 4 (bidirectional I/O) |
| Pin 23 | RC5 — Port C bit 5 (bidirectional I/O) |
| Pin 24 | RC6 — Port C bit 6 (bidirectional I/O) |
| Pin 25 | RC7 — Port C bit 7 (bidirectional I/O) |
| Pin 26 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 27 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 28 | RA6 — Port A bit 6 (bidirectional I/O) |
Typical Applications
PIC16C642-04I/SO is suitable for 6 applications: Industrial Control Systems, Appliance Control Boards, Security and Alarm Panels, Automotive Body Electronics, Battery Monitoring and Sensor Interface, Consumer Electronics Remote Controls and Toys.
Industrial Control Systems
The PIC16C642-04I/SO suits industrial control with 4 MHz clock delivering 200 ns deterministic instruction execution and 22 I/O for sensor/actuator interfacing. Its 4V-6V supply range and -40C to +85C industrial temperature grade handle factory floor conditions. The 7 KB OTP memory stores real-time control firmware; the two on-chip comparators enable threshold and zero-crossing detection for motor and process control.
Recommended
Appliance Control Boards
The PIC16C642-04I/SO is ideal for washing machines, dishwashers, microwave ovens, and HVAC control boards where deterministic real-time response matters. Its 22 high-current I/O pins (25 mA sink/source) directly drive LEDs, relays, and seven-segment displays without external drivers, reducing BOM cost. The 7 KB OTP memory holds appliance state machines and timer logic; OTP ensures code is locked at production for warranty protection.
Recommended
Security and Alarm Panels
The PIC16C642-04I/SO powers intrusion detection panels, fire alarm controllers, and access control systems requiring reliable non-volatile code storage. The 7 KB OTP memory prevents firmware tampering, while the 22 I/O accommodate multiple zone inputs and siren/keypad outputs. Its watchdog timer with dedicated RC oscillator ensures the panel recovers from software faults or EMI events, and the -40C to +85C range supports unheated installations.
Recommended
Automotive Body Electronics
The PIC16C642-04I/SO handles body control modules, lighting controllers, and instrument cluster logic where its OTP memory prevents unauthorized code modification. The 4V-6V supply tolerates automotive 12V battery transients when paired with proper regulation, and the -40C to +85C industrial grade covers cabin and under-hood body modules. The 22 I/O drive lamps, switches, and stepper motor controllers; the 4 MHz clock handles keypad scanning and PWM dimming.
Recommended
Battery Monitoring and Sensor Interface
The PIC16C642-04I/SO excels in battery management nodes and remote sensor interfaces thanks to its two on-chip analog comparators that perform voltage threshold and window detection without external components. The 4V-6V supply range is well-matched to multi-cell battery packs, and the 22 I/O handle multiplexed sensor channels. The 7 KB OTP stores lookup tables for battery chemistry compensation and sensor calibration curves.
Recommended
Consumer Electronics Remote Controls and Toys
The PIC16C642-04I/SO provides cost-effective embedded control for IR/RF remote controls, electronic toys, and small consumer appliances where the 7 KB OTP holds protocol stacks and user-interface logic. Its 22 I/O drive LED indicators, keypads, and transmit modules, while the 4 MHz clock handles real-time protocol bit-banging. The OTP programming prevents reverse engineering of proprietary IR/RF codes, protecting manufacturer IP.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C642-04I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C642-04/SO | PIC16C642-04E/SP | PIC16C642-04I/SP |
|---|---|---|---|---|
| Package | 28-SOIC (0.295", 7.50 mm) | 28-SOIC - same | 28-PDIP - through-hole | 28-PDIP - through-hole |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Operating Temperature | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +125C (Extended) | -40C to +85C (Industrial) |
| Clock Speed (this grade) | 4 MHz | 4 MHz - same | 4 MHz - same | 4 MHz - same |
| Program Memory | 7 KB (4K x 14) OTP | 7 KB OTP - same | 7 KB OTP - same | 7 KB OTP - same |
| RAM | 176 bytes | 176 bytes - same | 176 bytes - same | 176 bytes - same |
| I/O Pins | 22 | 22 - same | 22 - same | 22 - same |
| Supply Voltage | 4 V to 6 V | 4 V to 6 V - same | 4 V to 6 V - same | 4 V to 6 V - same |
| Mounting Type | Surface Mount | Surface Mount | Through-Hole (PDIP) | Through-Hole (PDIP) |
Key Differentiators
- Drop-in industrial temperature variant in same 28-SOIC package (vs PIC16C642-04/SO)
- Surface-mount 28-SOIC for compact PCB designs (vs PIC16C642-04I/SP (28-PDIP))
- Two on-chip analog comparators eliminate external components (vs PIC16C56A-04I/SO (smaller PIC16C variant))
Design Notes
The PIC16C642-04I/SO requires a stable 4V to 6V supply; decouple VDD (pin 20) with a 0.1 uF ceramic capacitor placed within 5 mm of the pin, plus a 10 uF bulk capacitor for transient suppression. Multiple VSS pins (5, 14, 21) must all be connected to ground for proper I/O drive symmetry. The PIC16C64X family does not include internal voltage regulation, so external 5V regulation is required for noisy environments.
Keep the oscillator traces (OSC1 pin 27, OSC2 pin 26) short and surrounded by a ground guard ring or ground pour to minimize EMI pickup. For crystal operation, place load capacitors (typically 15-33 pF) as close to OSC1/OSC2 as possible. Route the MCLR pin (pin 1) with a 10 kohm pull-up to VDD and a 0.1 uF capacitor for reliable reset; avoid running high-frequency signals near MCLR to prevent spurious resets.
OTP (One-Time Programmable) memory cannot be erased or rewritten - any code bug in the production firmware is permanent and requires a new physical part. Always verify firmware thoroughly using the flash-based PIC16F family or PIC16C642 prototype windowed (JW) variants before committing to OTP. Configuration bits (watchdog timer, code protection, oscillator mode) must be set correctly during programming; incorrect config bits can lock the device or cause erratic behavior.
The PIC16C642-04I/SO in 28-SOIC has a thermal resistance (theta_JA) of approximately 80 C/W. At maximum operating current of ~25 mA active plus I/O drive, total dissipation stays well under 200 mW, so no heatsink is required even at +85C ambient. However, in enclosed industrial enclosures with poor ventilation, derate ambient temperature by 10-15C to maintain junction temperature below the +150C maximum rating.
Compliance Information
RoHS, REACH, lead-free and halogen-free status not specified in the verified distributor data. Conflict minerals compliance inferred from Microchip Technology's standard corporate policy. AEC-Q100 automotive qualification is NOT listed for this industrial-grade part. For automotive applications, consider AEC-Q100 qualified alternatives in the PIC16F family.