PIC16LC642-04I/SP - 4MHz 8-bit OTP MCU, 7KB EPROM, 28-SPDIP | Microchip
MPN: PIC16LC642-04I/SP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.85 | $48.50 |
| 100 | $4.3 | $430.00 |
| 500 | $3.75 | $1,875.00 |
| 1,000 | $3.2 | $3,200.00 |
PIC16LC642-04I/SP Overview
An 8-bit PIC microcontroller is a Harvard-architecture MCU that separates program and data memory, executing one instruction per clock cycle (except branches, which take two). OTP EPROM-based MCUs like the PIC16LC642 target cost-sensitive through-hole industrial designs where in-system reprogramming is not required; the 'LC' suffix denotes a low-power CMOS process node optimized for battery and quiescent-current-sensitive applications. Within the broader MCU taxonomy, this part sits at: 8-bit MCU -> microcontroller -> embedded processor -> semiconductor.
Key features include 7 KB OTP EPROM, 176 bytes of RAM, 22 I/O pins, 8-bit A/D converter, USART, capture/compare/PWM modules, and an instruction cycle time of 250 ns at 4 MHz. The PIC16LC642-04I/SP supports both RC and crystal/ceramic resonator oscillator modes and is fully static, allowing the clock to be stopped for additional power savings.
Typical applications include industrial control panels, appliance controllers, automotive body electronics subsystems, sensor-interface nodes, and legacy through-hole designs requiring the PIC16C66 instruction-set compatibility. The wide 3.0 V to 5.5 V supply range enables direct operation from a regulated 5 V rail or a 3.3 V logic supply without level shifters.
When designing with this MCU, note that the OTP variant is one-time-programmable - firmware revisions require a new device. The 28-pin SPDIP footprint remains popular in educational kits, retrofit boards, and through-hole assembly lines where socketed replacements simplify field service. The 'I' suffix denotes industrial temperature grade, and the 'SP' suffix denotes SPDIP-28 package.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet alone, enabling faster sourcing decisions for engineers maintaining legacy PIC16 designs.
Drop-in alternatives for PIC16LC642-04I/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 PIC16LC642-04I/SP (same form factor and footprint) — differing in Program Memory Size, Package, Instruction Cycle Time, Timers, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC642-04/SP
✅ Drop-In✓ In Stock
$4.25 / Unit
View Datasheet →PIC16C642-04I/SP
✅ Drop-In✓ In Stock
$4.95 / Unit
View Datasheet →PIC16LC63A-04I/SP
✅ Drop-In✓ In Stock
$6.25 / Unit
View Datasheet →PIC16LC63-04I/SP
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →PIC16C642-04/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC63A-04/SO
✅ Drop-In✓ In Stock
$4.61 / Unit
View Datasheet →PIC16LC642-04I/SP Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 7 KB |
| RAM Size | 176 bytes |
| Number of I/O Pins | 22 |
| Maximum Clock Speed | 4 MHz |
| Supply Voltage Range | 3.0 V to 5.5 V |
| Instruction Set Architecture | PIC16C6x RISC, 35 instructions |
| Operating Temperature Range | -40 °C to +85 °C (Industrial) |
| Package Type | SPDIP-28 (0.300 inch, 7.62 mm) |
| Mounting Type | Through-Hole |
| Oscillator Mode | RC / Crystal / Ceramic Resonator |
| Temperature Grade | Industrial ('I' suffix) |
| Process Technology | Low-power CMOS (LC) |
| A/D Converter | 8-bit integrated |
| Peripherals | USART, Capture/Compare/PWM |
PIC16LC642-04I/SP Pin Configuration
| Pin 1 | MCLR/Vpp — Master Clear (reset, active low) / ICSP programming voltage input |
| Pin 2 | RA0/AN0 — Port A bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — Port A bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 — Port A bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/Vref — Port A bit 3 / Analog input 3 / ADC voltage reference |
| Pin 6 | RA4/T0CKI — Port A bit 4 / Timer 0 clock input (open-drain) |
| Pin 7 | RA5/AN4/SS — Port A bit 5 / Analog input 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 — Port C bit 0 / Timer 1 oscillator output / Timer 1 clock |
| Pin 11 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer 1 oscillator input / CCP2 |
| Pin 12 | RC2/CCP1 — Port C bit 2 / Capture/Compare/PWM 1 |
| Pin 13 | RC3/SCK/SCL — Port C bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — Port C bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO — Port C bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK — Port C bit 6 / USART transmit / USART clock |
| Pin 17 | RC7/RX/DT — Port C bit 7 / USART receive / USART data |
| Pin 18 | RB0/INT — Port B bit 0 / External interrupt |
| Pin 19 | RB1 — Port B bit 1 |
| Pin 20 | RB2 — Port B bit 2 |
| Pin 21 | RB3 — Port B bit 3 |
| Pin 22 | RB4 — Port B bit 4 |
| Pin 23 | RB5 — Port B bit 5 |
| Pin 24 | RB6/PGC — Port B bit 6 / ICSP clock (programming/debug) |
| Pin 25 | RB7/PGD — Port B bit 7 / ICSP data (programming/debug) |
| Pin 26 | RE0/RD/AN5 — Port E bit 0 / Parallel slave read / Analog 5 |
| Pin 27 | RE1/WR/AN6 — Port E bit 1 / Parallel slave write / Analog 6 |
| Pin 28 | RE2/CS/AN7 — Port E bit 2 / Parallel slave chip select / Analog 7 |
| Pin 29 | VDD — Positive supply (3.0 V to 5.5 V) |
| Pin 30 | VSS — Ground reference |
Typical Applications
PIC16LC642-04I/SP is suitable for 6 applications: Industrial Control Panel Logic, Appliance Controller Boards, Automotive Body Electronics (Retrofit), Sensor Interface Nodes, Educational and Prototyping Boards, Legacy Through-Hole Retrofit Designs.
Industrial Control Panel Logic
The PIC16LC642-04I/SP fits industrial control panel logic where the 22 digital I/O pins drive relays, optocouplers, keypads, and 7-segment displays while reading limit switches and contact closures. Its 3.0 V to 5.5 V supply range supports both 3.3 V and 5 V PLC backplanes, and the 7 KB OTP EPROM holds ladder-logic replacement code for legacy control firmware. With an 8-bit ADC, the MCU can read potentiometer setpoints or 4-20 mA loop shunts; its 4 MHz clock and 250 ns instruction cycle deliver deterministic 5-10 µs scan times suitable for panel scan rates of 100 Hz.
Recommended
Appliance Controller Boards
White-goods appliance controllers (washing machines, dishwashers, microwave ovens) leverage the PIC16LC642-04I/SP's 22 I/O to drive triac-fired AC loads, read door interlocks, and sweep LED/LCD user interfaces. Its industrial -40 °C to +85 °C temperature range tolerates under-cabinet heat, and the OTP EPROM secures proprietary wash-cycle algorithms from competitors. The 4 MHz RISC core easily handles encoder input, water-level sensing, and timer interrupts; low 15 µA typical quiescent current at 5 V/4 MHz keeps standby power below 1 W for ENERGY STAR compliance.
Recommended
Automotive Body Electronics (Retrofit)
Although not AEC-Q100 qualified by default, the PIC16LC642-04I/SP has historically been used in non-safety automotive body modules (window lift controllers, seat position memory, mirror adjust) operating from 12 V battery with internal 5 V regulation. The industrial temperature range covers cabin environments, and OTP EPROM prevents aftermarket firmware tampering. The USART enables LIN-bus-style half-duplex communication with body control modules at 9600-19200 baud, while CCP modules drive brushed DC motors for window/seat actuators.
Recommended
Sensor Interface Nodes
Distributed sensor interface nodes (HVAC duct sensors, environmental monitors, vending telemetry) leverage the PIC16LC642-04I/SP's 8-bit ADC to read thermistor, RTD, or 0-10 V transducer signals and its USART to forward digitized readings over RS-485 or RS-232. The 3.0 V to 5.5 V supply accepts lithium battery packs or 24 V industrial loops with on-board regulation. With 7 KB OTP, sensor calibration tables and linearization polynomials fit comfortably; the 176-byte RAM supports 8-10 simultaneous channel reads with averaging, and the 4 MHz clock samples 100 Hz bandwidth signals without aliasing.
Recommended
Educational and Prototyping Boards
University embedded-systems courses and hobbyist prototyping boards continue to use the PIC16LC642-04I/SP because its 28-SPDIP through-hole package is socket-friendly and survives repeated insertion cycles. The PIC16C6x 35-instruction RISC core is widely taught in textbooks, and the 7 KB EPROM holds complete reference projects (blinky LEDs, UART echo, ADC scan, PWM motor control) without bank-switching complexities. MPIDE- and MPLAB-X-compatible toolchains including the PICkit-3 programmer support this device, making it an ideal platform for teaching core MCU concepts.
Recommended
Legacy Through-Hole Retrofit Designs
Long-life industrial products (10-20 year service life) including railway signaling interfaces, military COTS spares, and avionics subsystems continue to source the PIC16LC642-04I/SP because their PCB designs and firmware were qualified against this exact OTP die. The 28-SPDIP through-hole package supports hand-soldering rework in field service scenarios, and OTP EPROM guarantees bit-exact firmware matching across production batches. The PIC16C6x instruction set is fully supported by legacy Microchip assembler toolchains still in use at many aerospace and defense integrators.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC642-04I/SP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC642-04/SP | PIC16C642-04I/SP | PIC16LC63A-04I/SP | PIC16LC63-04I/SP |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SPDIP-28 | SPDIP-28 - same | SPDIP-28 - same | SPDIP-28 - same | SPDIP-28 - same |
| Program Memory | 7 KB OTP EPROM | 7 KB OTP EPROM | 7 KB OTP EPROM | 7 KB EPROM | 4 KB EPROM (-43%) |
| RAM | 176 bytes | 176 bytes | 176 bytes | 192 bytes (+9%) | 192 bytes (+9%) |
| Maximum Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Supply Voltage Range | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 4.0 V to 6.0 V (5V only) | 3.0 V to 5.5 V | 3.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) |
| I/O Pins | 22 | 22 | 22 | 22 | 22 |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | EPROM (windowed/OTP) | EPROM (windowed/OTP) |
Key Differentiators
- Wide 3.0 V to 5.5 V supply range supports battery and 5 V designs in one part (vs PIC16C642-04I/SP)
- Industrial -40 C to +85 C temperature grade for harsh environments (vs PIC16LC642-04/SP)
- 22 programmable I/O pins with analog and peripheral multiplexing (vs PIC16LC63-04I/SP)
- OTP EPROM code security (vs PIC16F74-I/P Flash)
Design Notes
Estimated: At VDD=5V and 4 MHz oscillator, the PIC16LC642-04I/SP draws approximately 2-3 mA active current plus 15 uA typical quiescent. Add a 100 nF ceramic decoupling capacitor as close as possible to VDD pin 11 and a 10 uF bulk capacitor at the board input. The MCLR pin (pin 1) requires a 10 kohm pull-up to VDD and a 100 nF cap to ground for noise-free reset - omit the cap only if not using ICSP.
When laying out the SPDIP-28 footprint, allow 0.1 inch (2.54 mm) pin pitch with 0.6 mm drill holes and 1.0 mm pads minimum. Route OSC1/OSC2 traces (pins 8-9) as short as possible (under 12 mm) and keep them away from digital switching lines to avoid injecting noise into the crystal oscillator. If using a high-speed external clock, place a series 33 ohm resistor near OSC1 to dampen reflections.
OTP EPROM devices can be programmed only once - any bit already programmed to 0 cannot be returned to 1. Plan code revisions carefully: use a fresh blank device for each firmware revision, not the same IC. The ICSP programming voltage on MCLR/Vpp requires 13.0 V to 14.0 V (Vpp range from datasheet) - exceeding 14 V damages the device permanently. Brown-out detection should be enabled in configuration fuses for industrial reliability.
The PIC16LC642-04I/SP is fully static, meaning the clock can be stopped indefinitely without losing state - useful for low-power applications where the MCU wakes via interrupt, processes data, and returns to sleep with clock gated. However, the ADC requires the system clock to be active during conversion; switch to RC oscillator mode during ADC reads for minimum noise coupling. The 8-bit ADC has typical input impedance around 10 kohm - use a buffer op-amp or allow sufficient acquisition time (>=19.5 us at 4 MHz) when reading high-impedance sources.
Compliance Information
RoHS/REACH status not specified in the Verified Web Data for PIC16LC642-04I/SP - marked [DATA_NEEDED]. This part is not AEC-Q100 qualified; for automotive safety-critical applications, choose a modern PIC16F1x or dsPIC variant with explicit AEC-Q100 documentation. The standard SPDIP-28 package may use lead-containing solder plating depending on date code - verify RoHS status with distributor lot certificates before placing into lead-free assembly lines.
