PIC16LC662-04/PT - 7KB OTP MCU, 33 I/O, 4MHz | Microchip
MPN: PIC16LC662-04/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.95 | $5.95 |
| 10 | $5.36 | $53.60 |
| 100 | $4.76 | $476.00 |
| 500 | $4.29 | $2,145.00 |
| 1,000 | $3.81 | $3,810.00 |
PIC16LC662-04/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (ROM/Flash/OTP), working RAM, and peripheral interfaces such as timers, A/D converters, and digital I/O. PIC microcontrollers from Microchip use a Harvard architecture with a separate instruction bus and data bus, plus a RISC-style instruction set of only 35 instructions - one of the smallest instruction sets in the industry. Within the power-management and embedded hierarchy, MCUs sit between simple logic ICs and full microprocessors, providing programmable control for sensors, displays, motors, and communication interfaces.
Key features of the PIC16LC662-04/PT include the 35-instruction RISC core, single-cycle 200 ns execution (except branches), 33 digital I/O pins, an external oscillator interface, integrated peripherals (timers, capture/compare, A/D - per datasheet), and an operating temperature range typical of industrial-grade PIC parts. The 40-pin DIP package is one of the most assembly-friendly form factors, supporting both prototype breadboard work and legacy through-hole production lines that have not transitioned to surface mount.
Typical applications include industrial control panels, appliance controls, motor-control signal conditioning, HVAC controllers, instrumentation front-ends, and low-power remote sensor nodes. The 33 I/O count is generous for a 40-pin device and supports keypad scanning, LED matrix driving, and parallel LCD interfaces. The 4 MHz speed grade limits instruction throughput to 5 MIPS, which is appropriate for control loops and slow communication protocols rather than high-bandwidth signal processing.
When designing with this part, verify the exact peripheral set against the latest Microchip datasheet (the LC662 sub-family has subtle differences from the LC66/LC67). The OTP memory means firmware is permanently written at programming time - no field updates. Designers targeting longer product lifecycles should evaluate Flash-based PIC16F equivalents in the same pinout. The 40-pin DIP footprint is also widely supported by Flash PIC16F877A-style derivatives for direct replacement consideration.
This page synthesizes distributor pricing, drop-in alternatives sourced from Microchip cross-reference tools, and practical design notes not collated in the manufacturer datasheet, including package-specific PCB layout guidance and a parametric comparison against the PIC16LC662T-04/PT tape-and-reel variant and several Flash-based PIC16F derivatives.
Drop-in alternatives for PIC16LC662-04/PT — 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 PIC16LC662-04/PT (same form factor and footprint) — differing in Mounting Type, Program Memory Size, RAM Size, Operating Temperature, Package / Case.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16LC662T-04/PT
✅ Drop-In✓ In Stock
$5.65 / Unit
View Datasheet →PIC16LC662-04/L
✅ Drop-In✓ In Stock
$4.95 / Unit
View Datasheet →PIC16F877A-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F874A-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16LC662-04/PT Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Size | 8-bit |
| Program Memory Size | 7 KB (4K x 14) |
| Program Memory Type | OTP (One-Time-Programmable) |
| RAM Size | 176 x 8 bytes |
| Number of I/O | 33 |
| Package / Case | 40-DIP (0.600", 15.24 mm) |
| Mounting Type | Through-Hole |
| Speed (Clock Input) | 4 MHz |
| Instruction Cycle | 200 ns (single-cycle, except branches) |
| Number of Instructions | 35 |
| Oscillator Type | External |
| Series | PIC 16C |
| Packaging | Tube |
| Product Status | Obsolete |
PIC16LC662-04/PT Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage input |
| Pin 2 | RA0/AN0 — Port A bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 — Port A bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2 — Port A bit 2 / Analog input 2 |
| Pin 5 | RA3/AN3/VREF — Port A bit 3 / Analog input 3 / Voltage reference |
| Pin 6 | RA4/T0CKI — Port A bit 4 / Timer 0 clock input |
| Pin 7 | RA5/AN4/SS — Port A bit 5 / Analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — Port E bit 0 / Parallel port read control |
| Pin 9 | RE1/WR/AN6 — Port E bit 1 / Parallel port write control |
| Pin 10 | RE2/CS/AN7 — Port E bit 2 / Parallel port chip select |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer 1 oscillator output / Timer 1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer 1 oscillator input / Capture-Compare-PWM 2 |
| Pin 17 | RC2/CCP1 — Port C bit 2 / Capture-Compare-PWM 1 |
| Pin 18 | RC3/SCK/SCL — Port C bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — Port D bit 0 / Parallel Slave Port bit 0 |
| Pin 20 | RD1/PSP1 — Port D bit 1 / Parallel Slave Port bit 1 |
| Pin 21 | RD2/PSP2 — Port D bit 2 / Parallel Slave Port bit 2 |
| Pin 22 | RD3/PSP3 — Port D bit 3 / Parallel Slave Port bit 3 |
| Pin 23 | RC4/SDI/SDA — Port C bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — Port C bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — Port C bit 6 / USART transmit / USART clock |
| Pin 26 | RC7/RX/DT — Port C bit 7 / USART receive / USART data |
| Pin 27 | RD4/PSP4 — Port D bit 4 / Parallel Slave Port bit 4 |
| Pin 28 | RD5/PSP5 — Port D bit 5 / Parallel Slave Port bit 5 |
| Pin 29 | RD6/PSP6 — Port D bit 6 / Parallel Slave Port bit 6 |
| Pin 30 | RD7/PSP7 — Port D bit 7 / Parallel Slave Port bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RB0/INT — Port B bit 0 / External interrupt input |
| Pin 34 | RB1 — Port B bit 1 |
| Pin 35 | RB2 — Port B bit 2 |
| Pin 36 | RB3/PGM — Port B bit 3 / LVP programming input |
| Pin 37 | RB4 — Port B bit 4 |
| Pin 38 | RB5 — Port B bit 5 |
| Pin 39 | RB6/PGC — Port B bit 6 / ICD clock (PGC) |
| Pin 40 | RB7/PGD — Port B bit 7 / ICD data (PGD) |
Typical Applications
PIC16LC662-04/PT is suitable for 6 applications: Industrial Control Panels, Appliance Control (White Goods), HVAC and Building Automation Controllers, Instrumentation and Data Acquisition Front-Ends, Educational and Development Boards, Remote Sensor Nodes (Battery-Powered).
Industrial Control Panels
The PIC16LC662-04/PT fits industrial control panel designs where 33 digital I/O pins are sufficient to scan keypads, drive status LEDs, and read limit switches without external I/O expanders. Its 4 MHz clock input and 5 MIPS instruction throughput comfortably handle scan-loop logic at 1-10 ms intervals typical of operator-interface tasks. The 40-pin DIP through-hole package survives vibration-prone panel-mount environments better than fine-pitch SMD MCUs, and the LC low-voltage variant runs on 24 V industrial rails stepped down to 5 V or 3.3 V. Note that for new panel designs the Flash-based PIC16F877A-I/P is preferred, but the LC662-04/PT remains in legacy panels in production since the 1990s.
Recommended
Appliance Control (White Goods)
White-goods appliances such as washing machines, dishwashers, and microwave ovens traditionally use PIC16 mid-range MCUs because of their low cost, ruggedness, and proven long-term reliability. The PIC16LC662-04/PT's 33 I/O pins drive 7-segment displays, keypads, relay coils, and triac interfaces for motor and heater control. The 4 MHz clock and 35-instruction RISC set are sufficient for state-machine-based wash-cycle or cook-cycle logic. The OTP memory prevents firmware tampering in the field, which is sometimes a regulatory requirement for safety-certified appliances. For new appliance designs migrate to PIC16F1939 or PIC16F18855 successors.
Recommended
HVAC and Building Automation Controllers
HVAC controllers use PIC16 MCUs to read temperature sensors (via external ADC or thermistor voltage divider), drive triacs for fan-speed control, and switch relays for compressor and valve actuation. The PIC16LC662-04/PT's 33 I/O pins support multi-zone thermostats with up to 8 relay outputs and 8 sensor inputs simultaneously. The wide operating voltage of the LC family (typically 2.5 V to 6.0 V) accepts 5 V or 3.3 V regulated supplies common in HVAC boards. The external oscillator allows precise timing for line-frequency zero-crossing detection (50/60 Hz) used to phase-control triacs. Obsolescence of this part means new HVAC designs should specify PIC16F1765 or PIC16F18855.
Recommended
Instrumentation and Data Acquisition Front-Ends
Low-speed instrumentation front-ends, including weighing scales, multimeters, and process controllers, use the PIC16LC662-04/PT to sequence measurements, drive LCDs, and communicate via UART. The 4 MHz clock provides adequate throughput for sigma-delta ADC readouts at 10 Hz update rates. The 33 I/O support 4x4 keypads, 7-segment or character LCDs, and isolated UART or SPI links to upstream PCs. Note that this part lacks an integrated ADC, so external ADC ICs (such as MCP3201) must be added for analog measurements - a key limitation vs the PIC16F877A which integrates a 10-bit ADC.
Recommended
Educational and Development Boards
The PIC16LC662-04/PT's 40-pin DIP package makes it ideal for breadboard-based education - the through-hole leads are easy to insert into solderless breadboards, and the wide 0.1 inch pitch tolerates repeated insertion cycles. University courses on embedded systems and assembly programming have used PIC16C66x parts since the 1990s. The 35-instruction RISC set is small enough to teach the entire assembly language in a single semester. The external oscillator interface lets students experiment with different crystal frequencies. Although obsolete for production, thousands of these parts remain in legacy training kits and university inventory, justifying continued stock availability.
Recommended
Remote Sensor Nodes (Battery-Powered)
Battery-powered remote sensor nodes benefit from the LC low-voltage variant of the PIC16LC662 family. Operating down to 2.5 V allows the use of two AA alkaline cells in series (3.0 V nominal, drooping to 2.0 V at cutoff). Sleep-mode current in the LC family is in the microamp range, extending battery life to multi-year deployments. The 33 I/O pins accommodate multiple sensor channels (temperature, humidity, contact closure) and a low-power RF link via SPI. The 4 MHz clock allows rapid wake-measure-transmit-sleep cycles. The OTP memory prevents accidental firmware corruption that would brick a remote node.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC662-04/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC662T-04/PT | PIC16LC662-04/L | PIC16F877A-I/P | PIC16F874A-I/P |
|---|---|---|---|---|---|
| Package | 40-DIP (0.600") | 40-DIP - same | 40-DIP (ceramic windowed) - same footprint | 40-DIP - same | 40-DIP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Active | Active |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB EPROM (windowed) | 14 KB Flash | 7 KB Flash |
| RAM | 176 bytes | 176 bytes | 176 bytes | 368 bytes | 192 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Max Clock | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz |
| Integrated ADC | No (external required) | No | No | 8-channel 10-bit | 8-channel 10-bit |
| Operating Voltage (LC vs F) | 2.5 V to 6.0 V (LC) | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 4.0 V to 5.5 V (F standard) | 4.0 V to 5.5 V (F standard) |
Key Differentiators
- Low-voltage LC variant supports 2.5 V to 6.0 V operation (vs PIC16F877A-I/P (standard 4.0 V to 5.5 V F variant))
- External oscillator supports custom frequency selection (vs PIC16F628 with internal oscillator)
- 40-pin DIP through-hole package survives vibration (vs PIC16F877A-I/SP in SPDIP)
Design Notes
The PIC16LC662-04/PT OTP memory is one-time programmable - firmware errors cannot be corrected without replacing the device. Always program a freshly erased or new part for development, and use a windowed PIC16LC662-04/L (or Flash PIC16F877A-I/P equivalent) for iterative development. The OTP variant is intended only for production runs where firmware is finalized.
Estimated: at 4 MHz clock and 5 V VDD, the PIC16LC662-04/PT typical active current is approximately 2-5 mA depending on peripheral activity. Add a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 11 or 32) and a bulk 10 uF tantalum or ceramic on the supply rail. The LC variant's 2.5 V minimum allows 2xAA battery operation but verify brown-out reset behavior at the low-voltage cutoff.
The 40-pin DIP package has 0.1 inch (2.54 mm) pin pitch and through-hole leads suitable for breadboard prototyping. For PCB layout, allow at least 0.6 inch (15.24 mm) row-to-row spacing to clear the package body. Place the oscillator crystal (or resonator) within 1 cm of OSC1 (pin 13) and OSC2 (pin 14) with short, symmetric traces to minimize stray capacitance. Add a 1 MOhm parallel resistor across the crystal to bias the inverter into its linear region.
Obsolescence risk: PIC16LC662-04/PT is marked Obsolete by Octopart with lifecycle confirmation in 2026-09. Source from authorized distributors only (DigiKey, Mouser, OMO) to avoid counterfeit parts. For new designs, migrate to PIC16F877A-I/P (Flash, same 40-pin DIP) or PIC16F1939-I/P (newer peripherals, active lifecycle). Maintain a last-time-buy buffer if continued production is required.
The MCLR/VPP pin (pin 1) is shared between reset and high-voltage programming modes. Add a 10-100 kOhm pull-up to VDD and a 0.1 uF capacitor to ground to form an RC reset delay. Avoid long traces on MCLR to prevent noise-induced resets. For in-circuit debugging, route the PGC (pin 39) and PGD (pin 40) lines to a 5-pin ICSP header with 100 Ohm series resistors to limit inrush during programming.
Compliance Information
Compliance data not explicitly stated in the verified distributor listings. The PIC16LC662 family was originally released in the 1990s when lead-free compliance was not universal; check date code and finish for specific RoHS status. Microchip cross-reference tool should be consulted for the latest compliance declaration.
