PIC16C65AT-20/PT - 8-bit OTP MCU 7KB Flash 20MHz 44-TQFP | Microchip
MPN: PIC16C65AT-20/PT β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $13.2 | $132.00 |
| 100 | $11.75 | $1,175.00 |
| 500 | $10.4 | $5,200.00 |
| 1,000 | $9.25 | $9,250.00 |
PIC16C65AT-20/PT Overview
A PIC microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and configurable peripherals on one piece of silicon. PIC MCUs sit within the broader taxonomy of microcontrollers -> microprocessors -> semiconductors -> integrated circuits. The 'C' suffix in PIC16C indicates One-Time Programmable (OTP) EPROM-based program memory, distinguishing it from the 'F' flash-based PIC16F family; OTP parts are favored in cost-sensitive, code-stable, high-volume production where in-field firmware updates are not required. Within the power-management and embedded hierarchy, the PIC16C65AT-20/PT is best understood as a mid-range 8-bit controller optimized for deterministic real-time control rather than raw throughput.
Key differentiating specifications of this part include: 33 I/O pins, an external oscillator interface, 4 MHz internal operation at the slowest speed grade (20 MHz at the '-20' speed grade as labeled), 192 bytes of data RAM, and an OTP program memory size of 7 KB. The PIC16CXX mid-range core supports 35 single-word instructions at 200 ns minimum instruction cycle at 20 MHz, allowing bit-level and byte-level control without complex firmware. Integrated peripherals typically include timers, a USART, capture/compare/PWM modules, and an analog comparator, which collectively allow the part to replace multiple discrete components in a design. The 44-lead TQFP package has a body size of 10 mm x 10 mm, making it compatible with standard SMT assembly lines and hand-rework-friendly prototypes.
Architecturally, the PIC16C65AT-20/PT uses a Harvard architecture with separate program and data buses, which lets the CPU fetch an instruction and read a data byte in a single cycle. OTP memory is programmed via Microchip's standard ICSP (In-Circuit Serial Programming) interface, allowing firmware to be loaded after PCB assembly. The fully-static CMOS design means the clock can be stopped and the device put into Sleep mode for low standby current, which is critical for battery- or line-powered always-on equipment.
Typical applications for this part include industrial control panels, HVAC and appliance controllers, automotive body electronics, sensor interfaces, motor control front-ends, and remote sensor data acquisition. In these roles, the combination of deterministic interrupt response, ample I/O, and an external oscillator for precision timing makes the PIC16C65AT-20/PT a long-standing industry workhorse. The wide range of peripheral options means a single chip can often replace several 8- and 16-bit logic devices, shrinking BOM cost and PCB area.
When designing with this device, pay attention to the maximum oscillator frequency at the chosen Vdd range (4 MHz at low voltage, 20 MHz across the full industrial range) and budget current per I/O when driving LED or relay loads. Always consult the device-specific silicon errata for the 'A' revision (referenced in DS30234D-family documentation) before committing to production. This page synthesizes distributor pricing, drop-in alternatives within the PIC16C6X family, and practical design notes that go beyond the manufacturer datasheet.
Drop-in alternatives for PIC16C65AT-20/PT β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16F877A-20/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16F877-20/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C65A-20/PT
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16C65B-20/PT
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16F74-20/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16F767-I/PT
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16C65AT-20/PT Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Size | 8-bit |
| Program Memory Type | OTP (One-Time Programmable EPROM) |
| Program Memory Size | 7 KB (4K x 14) |
| RAM Size | 192 x 8 (192 bytes) |
| Number of I/O Pins | 33 |
| Speed (CPU Clock) | 20 MHz |
| Speed (Internal at Low Vdd) | 4 MHz |
| Oscillator Type | External |
| Package / Case | 44-TQFP (PT) 10 mm x 10 mm |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40C to +85C (industrial, per 'T' tape-and-reel code is not temperature) |
| Connectivity | I2C, SPI, UART/USART |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| Number of Timers | 3 |
| Packaging | Tape & Reel (TR) |
| Silicon Revision | A |
PIC16C65AT-20/PT Pin Configuration
| Pin 1 | MCLR/Vpp β Master Clear (reset) input / ICSP programming voltage |
| Pin 2 | RA0/AN0 β PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 β PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 β PORTA bit 2 / analog input 2 |
| Pin 5 | RA3/AN3/Vref+ β PORTA bit 3 / analog input 3 / ADC Vref+ |
| Pin 6 | RA4/T0CKI β PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS β PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 β PORTE bit 0 / parallel-port read / analog input 5 |
| Pin 9 | RE1/WR/AN6 β PORTE bit 1 / parallel-port write / analog input 6 |
| Pin 10 | RE2/CS/AN7 β PORTE bit 2 / parallel-port chip select / analog input 7 |
| Pin 11 | VDD β Positive supply voltage |
| Pin 12 | VSS β Ground reference |
| Pin 13 | OSC1/CLKIN β Oscillator input / external clock input |
| Pin 14 | OSC2/CLKOUT β Oscillator output / clock output (Fosc/4) |
| Pin 15 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator input / CCP2 I/O |
| Pin 17 | RC2/CCP1 β PORTC bit 2 / CCP1 I/O (PWM/capture/compare) |
| Pin 18 | RC3/SCK/SCL β PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 β PORTD bit 0 / parallel slave port bit 0 |
| Pin 20 | RD1/PSP1 β PORTD bit 1 / parallel slave port bit 1 |
| Pin 21 | RD2/PSP2 β PORTD bit 2 / parallel slave port bit 2 |
| Pin 22 | RD3/PSP3 β PORTD bit 3 / parallel slave port bit 3 |
| Pin 23 | RC4/SDI/SDA β PORTC bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO β PORTC bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK β PORTC bit 6 / USART TX / USART sync clock |
| Pin 26 | RC7/RX/DT β PORTC bit 7 / USART RX / USART sync data |
| Pin 27 | RD4/PSP4 β PORTD bit 4 / parallel slave port bit 4 |
| Pin 28 | RD5/PSP5 β PORTD bit 5 / parallel slave port bit 5 |
| Pin 29 | RD6/PSP6 β PORTD bit 6 / parallel slave port bit 6 |
| Pin 30 | RD7/PSP7 β PORTD bit 7 / parallel slave port bit 7 |
| Pin 31 | VSS β Ground reference |
| Pin 32 | VDD β Positive supply voltage |
| Pin 33 | RB0/INT β PORTB bit 0 / external interrupt input |
| Pin 34 | RB1 β PORTB bit 1 |
| Pin 35 | RB2 β PORTB bit 2 |
| Pin 36 | RB3 β PORTB bit 3 |
| Pin 37 | RB4 β PORTB bit 4 |
| Pin 38 | RB5 β PORTB bit 5 |
| Pin 39 | RB6/PGC β PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD β PORTB bit 7 / ICSP data |
| Pin 41 | NC β Not connected (per datasheet) |
| Pin 42 | NC β Not connected (per datasheet) |
| Pin 43 | NC β Not connected (per datasheet) |
| Pin 44 | NC β Not connected (per datasheet) |
Typical Applications
PIC16C65AT-20/PT is suitable for 7 applications: Industrial Control Panels, HVAC and Appliance Controllers, Automotive Body Electronics, Sensor Interface and Data Acquisition, Motor Control Front-End, Remote Sensor / Telemetry Nodes, Consumer Appliance User Interfaces.
Industrial Control Panels
The PIC16C65AT-20/PT is a strong fit for industrial control panels because it integrates 33 digital I/O pins, 7 KB of OTP program memory, and 192 bytes of RAM in a single 44-TQFP chip - sufficient for scan-matrix key handling, LED multiplexing, relay/SSR drive, and isolated digital I/O. Its 20 MHz core delivers a 200 ns instruction cycle, well-suited to deterministic scan loops running at millisecond intervals. The PIC16C65AT-20/PT's external oscillator lets the design reference a precision clock for time-stamping and synchronization to PLC backplanes. Unlike discrete 8051 designs, this single-chip solution shrinks BOM and PCB area, while OTP memory locks firmware against field tampering. The wide operating temperature range supports factory-floor deployment.
Recommended
HVAC and Appliance Controllers
The PIC16C65AT-20/PT fits HVAC and appliance controllers because its PWM, capture, and timer peripherals can drive triac-fired heater elements, sense NTC thermistors through the analog comparator, and decode zero-cross events from the AC mains - all without external glue logic. With 7 KB of OTP, control algorithms for proportional-integral loops, defrost scheduling, and safety interlocks fit comfortably. The 33 I/O pins handle multiple relay banks, keypad inputs, seven-segment displays, and communication to indoor/outdoor units. OTP memory protects appliance firmware from accidental or malicious in-field rewrite. Compared with a discrete logic controller, the PIC16C65AT-20/PT slashes component count, simplifies EMC compliance, and improves temperature stability through integrated peripherals.
Recommended
Automotive Body Electronics
The PIC16C65AT-20/PT is well-matched to automotive body electronics such as central locking, mirror control, lighting modules, and seat controllers because its 33 I/O pins connect directly to switches, LED drivers, and LIN/CAN companion transceivers. The 20 MHz core executes body-control logic, debounce, and PWM dimming at sub-millisecond cadence. OTP program memory locks the calibration per vehicle variant, which prevents unauthorized in-field modification of safety-relevant logic. The industrial temperature rating and external oscillator support 12 V automotive battery environments with cold-crank tolerance. Drop-in migration to PIC16F877A-20/PT enables firmware update over diagnostic lines for serviceability, while retaining the same 44-TQFP footprint.
Recommended
Sensor Interface and Data Acquisition
The PIC16C65AT-20/PT serves sensor-interface front-ends well because its I/O count, USART, and SPI peripherals let it poll, format, and forward data from multiple digital sensors (temperature, pressure, flow) into a host PLC or display. The 192-byte RAM buffers short sensor frames; the 7 KB OTP stores calibration tables and protocol stacks. With an external oscillator, timing for SPI clock generation is precise and stable across temperature. The 20 MHz CPU allows real-time streaming at typical sensor baud rates up to 1 Mbaud. OTP memory locks calibration against drift, while the 44-TQFP package supports compact, sealed enclosure designs for harsh environments.
Recommended
Motor Control Front-End
The PIC16C65AT-20/PT fits small motor-control front-ends because its PWM module, capture inputs, and 33 I/O pins generate complementary drive signals for half-bridge MOSFET drivers, sense back-EMF, and decode Hall-sensor feedback at up to 20 MHz clock resolution. The PIC mid-range core handles PID loop calculation with predictable interrupt latency thanks to its single-cycle instruction timing. OTP memory secures motor calibration and tuning parameters against unauthorized change. Compared with an analog-only control board, the PIC16C65AT-20/PT provides soft-start, current limiting, and stall detection in firmware. The 44-TQFP footprint supports integration on small driver boards close to the motor.
Recommended
Remote Sensor / Telemetry Nodes
The PIC16C65AT-20/PT is well-suited for remote telemetry nodes because its low-power Sleep mode, external oscillator option, and on-chip peripherals (USART, timers, PWM) let it wake periodically, take a sensor reading, transmit over a radio modem, and return to Sleep - all under firmware control with deterministic timing. The 7 KB OTP accommodates simple TDMA-style medium-access logic and sensor processing routines. OTP locks the network address and security key against field tampering. The 33 I/O pins support multiple sensor channels and a UART link to the RF modem. Compared with bare-metal discrete logic, the PIC16C65AT-20/PT enables robust, low-duty-cycle remote nodes with predictable behavior.
Recommended
Consumer Appliance User Interfaces
The PIC16C65AT-20/PT fits consumer appliance user interfaces because its 33 I/O pins drive multiplexed 7-segment or character-LCD displays, scan keypads, and toggle indicator LEDs. The 20 MHz core updates the display at flicker-free rates and debounces key inputs with predictable timing. OTP program memory locks brand-specific UI layouts, preventing end-user reprogramming. The internal peripherals (timers, PWM, USART) also communicate with the main appliance control board, providing a clean separation between UI logic and power-stage logic. The 44-TQFP package is hand-rework-friendly, allowing service technicians to swap boards quickly. Migration to PIC16F877A-20/PT is pin-compatible for production refreshes.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65AT-20/PT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F877A-20/PT | PIC16F877-20/PT | PIC16C65A-20/PT | PIC16F74-20/PT |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (PT) 10x10 mm | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same |
| Program Memory Type | OTP (7 KB) | Flash (14 KB) | Flash (14 KB) | OTP (7 KB) | Flash (7 KB) |
| RAM Size | 192 bytes | 368 bytes | 368 bytes | 192 bytes | 192 bytes |
| Number of I/O | 33 | 33 | 33 | 33 | 33 |
| Max CPU Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| ADC | 8 channels, 8-bit (per 'A' rev family datasheet) | 8 channels, 10-bit | 8 channels, 10-bit | 8 channels, 8-bit | 8 channels, 8-bit |
| Lifecycle Status | Obsolete | Active | NRND / Last-time-buy | Obsolete | Obsolete |
| Peripherals (PWM / UART / I2C / SPI) | 2 PWM, 1 UART, 1 I2C/SPI, 1 PSP | 2 PWM, 1 UART, 1 I2C/SPI, 1 PSP | 2 PWM, 1 UART, 1 I2C/SPI, 1 PSP | 2 PWM, 1 UART, 1 I2C/SPI, 1 PSP | 2 PWM, 1 UART, 1 I2C/SPI, no PSP |
Key Differentiators
- 33 I/O in 44-TQFP with integrated PSP and dual PWM - one of the highest pin-count 8-bit PIC16C6X OTP variants (vs PIC16F74-20/PT)
- Locks firmware via OTP against field reprogramming - ideal for tamper-resistant and code-stable production (vs PIC16F877A-20/PT)
- Highest pin count in the PIC16C6X OTP family on 44-TQFP (vs PIC16C63A-04/SP (28-pin SOIC))
Design Notes
Estimated: At Vdd = 5 V and 20 MHz external oscillator, the PIC16C65AT-20/PT typical operating current is roughly 13 mA in active mode (per Microchip PIC16C6X datasheet DC characteristics). Power dissipation at full I/O drive and active peripherals is therefore ~65 mW per chip; budget less than 100 mW per MCU when designing 5 V supply rails. Use a 100 nF ceramic decoupling capacitor as close as possible to each Vdd/Vss pair (two pairs on the 44-TQFP package), plus a 10 uF bulk capacitor on the supply rail. For low-duty-cycle applications, leverage Sleep mode to drop quiescent current to typical < 1 uA (Watchdog Timer disabled) before deciding on battery sizing.
Never attempt to reprogram OTP memory - the PIC16C65AT-20/PT can only be programmed once. Build at least two prototype units per firmware revision to allow rework and verification. When migrating firmware from PIC16C65 to PIC16C65A 'A' silicon, read the device errata (DS30234D-family errata sheet) for changes in USART baud-rate tolerance and brown-out reset behavior. Always tie MCLR to Vdd through a 10 kohm resistor with a 100 nF cap to ground for clean reset; floating MCLR can cause spurious resets on noisy industrial rails. Do not drive any I/O pin beyond absolute maximum ratings (20 mA source/sink per pin, 200 mA total package).
The 44-TQFP (PT) package has a 0.80 mm lead pitch with a 10 mm x 10 mm body. Design the PCB land pattern per IPC-7351 nominal density, with 0.30 mm pad width and 1.50 mm pad length. Place the crystal or resonator within 10 mm of OSC1/OSC2, and keep digital switching traces away from the oscillator loop to minimize jitter. Route the ICSP signals (RB6/PGC, RB7/PGD, MCLR) to a 5-pin header or test pad so production programming is possible without an additional adapter. Provide a solid ground plane under the device for thermal dissipation and EMI suppression.
Compliance Information
Compliance status was not explicitly stated in the Verified Web Data. RoHS/REACH compliance for OTP PIC16C6X parts is mixed in industry databases; request a compliance certificate from your distributor before use in RoHS-bound end products. AEC-Q100 qualification: not stated in data; industrial-grade (-40C to +85C) only - not automotive-qualified.
