PIC16C65AT-20I/PT - 8-Bit OTP MCU, 7KB, 33 I/O | Microchip
MPN: PIC16C65AT-20I/PT ✗ End of LifePIC16C65AT-20I/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory (ROM/RAM), and programmable I/O peripherals. The PIC16C65A belongs to the mid-range PIC family, sitting in the taxonomy of microcontrollers -> embedded controllers -> microprocessors -> semiconductors. OTP memory is field-programmable but not erasable, making the PIC16C65A well-suited for low-cost production runs where firmware stability is verified before mask programming.
Key features include Harvard architecture with separate program and data buses, 35 single-word RISC instructions, DC to 20 MHz operating speed, and an industrial-grade -40C to +85C operating temperature range (the "/I" suffix). Power management is handled via SLEEP mode with multiple wake-up sources. The 44-pin TQFP (PT) package provides a compact 10 mm x 10 mm footprint suitable for space-constrained designs.
Typical applications include industrial control logic, motor control front-ends, sensor interfacing boards, HVAC controls, automotive body electronics (non-safety), and embedded instrumentation. The integrated A/D converter and USART simplify designs that previously required external glue logic.
When designing with this part, account for OTP memory limitations - firmware must be fully validated before programming because the device cannot be re-programmed. Use the parallel slave port for high-speed data acquisition and the USART for asynchronous serial communication with a host processor.
Drop-in alternatives for PIC16C65AT-20I/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 PIC16C65AT-20I/PT (same form factor and footprint) — differing in Core Architecture, RAM Size, Program Memory Size, Program Memory Type, ADC.
PIC16F877A-I/PT
✅ Drop-InContact for price
View Datasheet →PIC16C65A-20I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65AT-20/PT
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →PIC16C65AT-20E/PT
✅ Drop-InContact for price
View Datasheet →PIC16F874A-I/PT
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC16C65B-20I/PT
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →PIC16C65AT-20I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC mid-range |
| Family | PIC16C6X |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 x 8 bytes |
| Number of I/O | 33 |
| Maximum Clock Frequency | 20 MHz |
| Instruction Set | 35 single-word RISC instructions |
| ADC | 8-bit, 8 channels |
| Timers | 2 x 8-bit, 1 x 16-bit |
| Communication | USART, SSP (SPI/I2C) |
| Parallel Slave Port | 8-bit |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 44-pin TQFP (PT), 10x10 mm |
| Mounting Type | Surface Mount |
PIC16C65AT-20I/PT 44-pin tqfp (pt), 10x10 mm Pin Configuration Guide
Pin configuration for PIC16C65AT-20I/PT (44-pin tqfp (pt), 10x10 mm package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for PIC16C65AT-20I/PT.
Refer to the datasheet for full pin configuration.
Typical Applications
PIC16C65AT-20I/PT is suitable for 6 applications: Industrial Control Logic, Motor Control Front-End, HVAC Control Systems, Sensor Interfacing Boards, Automotive Body Electronics, Embedded Instrumentation.
Industrial Control Logic
The PIC16C65AT-20I/PT fits industrial control logic boards because its 33 I/O pins, 8-channel 8-bit ADC, and 20 MHz RISC core handle multiple sensor inputs and actuator outputs in a single chip. The integrated USART and SSP enable networking with industrial protocols like Modbus RTU. Industrial temperature grade (-40C to +85C) suits factory floor environments.
Recommended
Motor Control Front-End
The PIC16C65AT-20I/PT drives motor control front-ends with its Timer1 (16-bit) module for precise PWM generation and 8-bit ADC for current sensing feedback. The 44-pin TQFP package provides ample I/O for multiple MOSFET gate drivers, encoder inputs, and fault detection signals. The /I suffix ensures operation in motor-drive ambient temperatures.
Recommended
HVAC Control Systems
The PIC16C65AT-20I/PT is suitable for HVAC control boards, reading temperature sensors via its 8-channel ADC and driving relays, fan controls, and valve actuators through its 33 I/O pins. The USART interfaces with display modules and remote thermostats. The wide industrial temperature range supports attic and outdoor HVAC equipment.
Recommended
Sensor Interfacing Boards
The PIC16C65AT-20I/PT serves as the main processor in sensor interfacing boards where its integrated 8-bit ADC, multiple timers, and SSP/I2C peripherals simplify designs. The 7 KB OTP memory fits deterministic sensor processing firmware. Parallel slave port enables fast data transfer to host processors in data acquisition systems.
Recommended
Automotive Body Electronics
The PIC16C65AT-20I/PT is used in non-safety automotive body modules like seat controllers, mirror adjusters, and lighting controllers where its -40C to +85C operating range covers automotive cabin temperatures. The OTP memory prevents unauthorized firmware tampering. The 33 I/O pins support multiple switch inputs and PWM-controlled loads.
Recommended
Embedded Instrumentation
The PIC16C65AT-20I/PT powers embedded instrumentation such as digital panel meters, data loggers, and bench instruments. Its USART provides serial data output to PCs, the ADC reads measurement signals, and the parallel slave port enables high-speed parallel data capture. The 20 MHz instruction rate supports real-time DSP-like filtering routines.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65AT-20I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F877A-I/PT | PIC16C65A-20I/PT | PIC16C65AT-20E/PT | PIC16F874A-I/PT | PIC16C65B-20I/PT |
|---|---|---|---|---|---|---|
| Package | 44-pin TQFP (PT) | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Size | 7 KB OTP | 14 KB Flash | 7 KB OTP | 7 KB OTP | 7 KB Flash | 7 KB OTP |
| Program Memory Type | OTP | Flash (re-programmable) | OTP | OTP | Flash (re-programmable) | OTP |
| RAM Size | 192 bytes | 368 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C | -40C to +85C | -40C to +125C (extended) | -40C to +85C | -40C to +85C |
| Lifecycle Status | Obsolete | Active | Obsolete | Obsolete | Active | Obsolete |
Key Differentiators
- Lower cost vs flash-based equivalent (vs PIC16F877A-I/PT)
- Industrial temperature range standard (vs PIC16C65AT-20/PT)
- Drop-in compatible flash replacement available (vs PIC16F877A-I/PT)
Design Notes
OTP (One-Time Programmable) memory cannot be erased or rewritten. Once the PIC16C65AT-20I/PT is programmed, the firmware is permanent. Engineers must fully verify firmware on a flash-based development equivalent (e.g., PIC16F877A) before programming production units. Misprogramming results in scrapped parts and significant cost.
The PIC16C65AT-20I/PT requires stable Vdd decoupling. Place a 100 nF ceramic capacitor as close as possible to each Vdd/Vss pin pair, plus a bulk 10 uF tantalum or electrolytic capacitor on the main supply rail. Brown-out detection must be enabled in the configuration word to prevent code corruption during supply dips below the operating threshold.
The 44-pin TQFP (PT) package has a 0.8 mm lead pitch requiring careful PCB layout. Use 4 mil trace/space rules minimum, and consider micro-via fanouts for inner pads. The exposed thermal pad (if present in this package variant) should be soldered to a copper pour to improve thermal dissipation, although the PIC16C65A has modest power consumption.
The PIC16C65AT-20I/PT oscillator circuit is sensitive to noise and capacitive loading. Use a crystal with the load capacitance specified in the datasheet (typically 15-33 pF) and place the crystal within 5 mm of the OSC1/OSC2 pins. For high-noise environments (motor control), use a 4-layer PCB with a dedicated ground plane beneath the oscillator traces.
Compliance Information
Compliance status not explicitly stated in verified data. PIC16C6X OTP family pre-dates widespread RoHS compliance documentation. Marked [DATA_NEEDED] in specs.