PIC16C65A-10/PT - 8-bit OTP MCU 7KB 10MHz TQFP-44 | Microchip
MPN: PIC16C65A-10/PT β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.95 | $6.95 |
| 10 | $6.1 | $61.00 |
| 100 | $5.2 | $520.00 |
| 500 | $4.55 | $2,275.00 |
| 1,000 | $4.1 | $4,100.00 |
PIC16C65A-10/PT Overview
The PIC microcontroller is an 8-bit Harvard-architecture RISC processor family developed by Microchip Technology, widely used in embedded control applications. Microcontrollers (MCUs) integrate a CPU core, program memory, working RAM, and peripheral interfaces on a single silicon die, and they sit at the lowest level of the embedded system hierarchy: MCU -> microcontroller -> embedded controller -> semiconductor IC. Mid-range PIC16C devices like the PIC16C65A add interrupt-driven I/O, on-chip timers, and synchronous/asynchronous serial ports while keeping the instruction set small enough for deterministic real-time control. The 'A' suffix denotes the enhanced silicon revision with bug fixes over the original PIC16C65 silicon, and the 'C' in PIC16C indicates CMOS fabrication for low power consumption.
Key features include four 8-bit I/O ports (PORTA through PORTE, with PORTB/C supporting high-current drive), a 16-bit timer/counter (TMR1) plus two 8-bit timers (TMR0, TMR2), a 10-bit-resolution ADC with 8 input channels (on most PIC16C65A package options), and a watchdog timer for fault recovery. Brown-out-reset, power-on-reset, and an in-circuit serial programming interface are integrated. Operating voltage spans 2.5V to 5.5V (commercial) or 2.5V to 6.0V (industrial, /I suffix) at industrial temperature range -40C to +85C.
The PIC16C65A uses Microchip's mid-range 14-bit instruction set and shares peripheral architecture with the PIC16C63 and PIC16C64 families, enabling code portability across the family. The Harvard bus structure separates program and data memory for single-cycle instruction fetch, and the 8-level hardware stack supports nested subroutine calls. Sleep mode current is typically < 1 uA, making the part suitable for battery-powered instruments. Compared to modern PIC16F1xxx flash parts, the OTP-only PIC16C65A is intended for low-to-medium volume production or legacy system replication.
Typical applications include industrial control and automation systems, automotive body and chassis electronics (with automotive-grade /Q suffix variants), HVAC controls, appliance controllers, instrumentation front-ends, and embedded sensor interfaces where the 33 I/O pins directly drive relays, keypads, and LED/LCD panels. The integrated UART also suits legacy point-of-sale terminals and RS-485 networked devices.
When designing with this part, remember that OTP memory cannot be erased electrically; prototypes should be developed on the pin-compatible PIC16F877A flash part, then moved to PIC16C65A for production. A 4 MHz to 10 MHz crystal or ceramic resonator is required on OSC1/OSC2, and decoupling capacitors must be placed within 5 mm of VDD/VSS pins for noise immunity.
This page synthesizes distributor pricing, drop-in alternatives within the PIC16C family, and practical design notes not consolidated in the manufacturer datasheet.
Drop-in alternatives for PIC16C65A-10/PT β 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 PIC16C65A-10/PT (same form factor and footprint) β differing in Operating Temperature Range, Program Memory Size, Program Memory Type, Timers.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C65A-04/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C65A-20/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C64A-10/PT
β Drop-Inβ In Stock
$2.97 / Unit
View Datasheet βPIC16F877A-10/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16F877A-20/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C65A-10/PT Maximum Ratings & Electrical Characteristics
| Core Processor | PIC |
| Core Architecture | 8-bit RISC (Harvard) |
| Maximum Clock Frequency | 10 MHz |
| Program Memory Size | 7 KB (4K x 14) OTP |
| RAM Size | 192 bytes |
| Number of I/O Pins | 33 |
| Package Type | 44-pin TQFP |
| Mounting Type | Surface Mount |
| Supply Voltage Range | 2.5 V to 5.5 V (commercial) |
| Operating Temperature Range | 0C to +70C (commercial) / -40C to +85C (industrial, -I suffix) |
| Instruction Set Width | 14 bits |
| Connectivity | I2C (MSSP), SPI, USART (RS-232/RS-485) |
| Timers | 3 (TMR0 8-bit, TMR1 16-bit, TMR2 8-bit) |
| Watchdog Timer | Yes (WDT with dedicated RC oscillator) |
| Program Memory Type | One-Time Programmable (OTP) |
| Stack Depth | 8 levels (hardware) |
PIC16C65A-10/PT Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (reset) input / 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 / VREF- |
| Pin 6 | RA4/T0CKI β PORTA bit 4 / TMR0 clock input |
| Pin 7 | RA5/AN4/SS β PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 8 | OSC2/CLKOUT β Oscillator output / clock output |
| Pin 9 | OSC1/CLKIN β Oscillator input / external clock in |
| Pin 10 | VSS β Ground |
| Pin 11 | VDD β Positive supply |
| Pin 12 | RC0/T1OSO/T1CKI β PORTC bit 0 / TMR1 oscillator output / TMR1 clock input |
| Pin 13 | RC1/T1OSI/CCP2 β PORTC bit 1 / TMR1 oscillator input / CCP2 output |
| Pin 14 | RC2/CCP1 β PORTC bit 2 / CCP1 PWM output |
| Pin 15 | RC3/SCK/SCL β PORTC bit 3 / SPI clock / I2C clock |
| Pin 16 | RC4/SDI/SDA β PORTC bit 4 / SPI data in / I2C data |
| Pin 17 | RC5/SDO β PORTC bit 5 / SPI data out |
| Pin 18 | RC6/TX/CK β PORTC bit 6 / USART TX / USART clock |
| Pin 19 | RC7/RX/DT β PORTC bit 7 / USART RX / USART data |
| Pin 20 | VSS β Ground |
| Pin 21 | VDD β Positive supply |
| Pin 22 | RB0/INT β PORTB bit 0 / external interrupt |
| Pin 23 | RB1 β PORTB bit 1 |
| Pin 24 | RB2 β PORTB bit 2 |
| Pin 25 | RB3/PGM β PORTB bit 3 / low-voltage programming |
| Pin 26 | RB4 β PORTB bit 4 |
| Pin 27 | RB5 β PORTB bit 5 |
| Pin 28 | RB6/PGC β PORTB bit 6 / ICSP clock |
| Pin 29 | RB7/PGD β PORTB bit 7 / ICSP data |
| Pin 30 | VSS β Ground |
| Pin 31 | VDD β Positive supply |
| Pin 32 | RD0 β PORTD bit 0 |
| Pin 33 | RD1 β PORTD bit 1 |
| Pin 34 | RD2 β PORTD bit 2 |
| Pin 35 | RD3 β PORTD bit 3 |
| Pin 36 | RD4 β PORTD bit 4 |
| Pin 37 | RD5 β PORTD bit 5 |
| Pin 38 | RD6 β PORTD bit 6 |
| Pin 39 | RD7 β PORTD bit 7 |
| Pin 40 | VSS β Ground |
| Pin 41 | VDD β Positive supply |
| Pin 42 | RE0/RD β PORTE bit 0 / parallel slave port read |
| Pin 43 | RE1/WR β PORTE bit 1 / parallel slave port write |
| Pin 44 | RE2/CS β PORTE bit 2 / parallel slave port chip select |
Typical Applications
PIC16C65A-10/PT is suitable for 6 applications: Industrial Control and Automation, HVAC and Building Automation, Appliance Control (White Goods), Point-of-Sale Terminals and Legacy RS-232 Devices, Automotive Body and Chassis Electronics, Embedded Sensor and Instrumentation Front-Ends.
Industrial Control and Automation
The PIC16C65A-10/PT is well-suited for industrial control panels, conveyor controllers, and machine-tool interfaces because its 33 digital I/O pins directly drive relays, solenoids, and optocouplers without external buffers. The 10 MHz instruction cycle supports deterministic 1 ms scan-loop timing, while the integrated USART and MSSP peripherals handle RS-485 multidrop and SPI sensor links. Brown-out-reset and watchdog-timer features protect against the brown-out and ESD transients typical of factory-floor 24V rails. The 44-pin TQFP surface-mount package withstands industrial vibration when paired with proper PCB staking.
Recommended
HVAC and Building Automation
The PIC16C65A-10/PT fits HVAC zone controllers, thermostat heads, and building-automation nodes thanks to its wide 2.5V-5.5V supply range and low 1 uA sleep current that suits battery-backed thermostats. The 192-byte RAM comfortably holds scheduler state and sensor history, while the integrated I2C bus connects to temperature/humidity sensors and the SPI channel drives graphical LCDs. Three timers (TMR0, TMR1, TMR2) deliver PWM outputs for damper and valve actuators. Industrial -40C to +85C variants handle outdoor rooftop unit enclosures.
Recommended
Appliance Control (White Goods)
Washing machines, dishwashers, and microwave-oven controllers benefit from the PIC16C65A-10/PT's 33 high-current I/O pins that can source 25 mA per pin to directly drive LED indicators, triac optocouplers, and seven-segment displays without external drivers. The 10 MHz MIPS performance handles fuzzy-logic wash-cycle algorithms and inverter compressor control loops. The OTP memory and visible pricing make the part attractive for cost-sensitive high-volume appliance production. The watchdog timer protects against lockup from motor EMI.
Recommended
Point-of-Sale Terminals and Legacy RS-232 Devices
The PIC16C65A-10/PT's integrated RS-232-capable USART and 10 MHz instruction rate suit legacy point-of-sale terminals, barcode scanners, and serial-connected cash-drawer controls. The 192-byte RAM buffers packetized RS-232 frames while the MSSP peripheral interfaces with mag-stripe readers in SPI mode. Brown-out-reset prevents corrupted transactions during power glitches typical of retail register environments. The TQFP-44 surface-mount package enables compact PCB layouts in space-constrained POS enclosures.
Recommended
Automotive Body and Chassis Electronics
Automotive body controllers, instrument clusters, and lighting modules are classic applications for the PIC16C65A family because the 44-pin TQFP provides enough I/O for switch-scanning matrices, lamp drivers, and CAN/lin gateway logic. The 10 MHz clock handles switch debouncing and PWM headlamp-leveling algorithms within tight interrupt latency budgets. Industrial-temperature variants rated to -40C to +85C cover most cabin and under-hood locations. The OTP memory locks firmware against unauthorized reflashing in deployed ECUs.
Recommended
Embedded Sensor and Instrumentation Front-Ends
Laboratory instruments, data-loggers, and process-meter front-ends use the PIC16C65A-10/PT as a low-cost supervisory controller that aggregates analog sensor data via its ADC inputs and forwards it through the USART to a host PC or display. The 10 MHz instruction rate comfortably handles 9600-115200 baud serial streams without UART overrun. The 7KB OTP program memory stores calibration tables and command interpreters for standalone instrumentation operation. The wide supply range accepts unregulated 5V or 3.3V rails typical of benchtop equipment.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65A-10/PT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65A-04/PT | PIC16C65A-20/PT | PIC16C64A-10/PT | PIC16F877A-10/PT | PIC16F877A-20/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin TQFP | 44-pin TQFP - same | 44-pin TQFP - same | 44-pin TQFP - same | 44-pin TQFP - same | 44-pin TQFP - same |
| Maximum Clock Frequency | 10 MHz | 4 MHz | 20 MHz | 10 MHz | 10 MHz | 20 MHz |
| Program Memory Type | OTP (7KB) | OTP (7KB) | OTP (7KB) | OTP (3.5KB) | Flash (7KB) | Flash (7KB) |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 128 bytes | 368 bytes | 368 bytes |
| EEPROM | 0 bytes | 0 bytes | 0 bytes | 0 bytes | 256 bytes | 256 bytes |
| Number of I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| Connectivity | I2C, SPI, USART | I2C, SPI, USART | I2C, SPI, USART | I2C, SPI, USART | I2C, SPI, USART + PSP | I2C, SPI, USART + PSP |
| Lifecycle Status | NRND | NRND | NRND | NRND | Active | Active |
| Approx Unit Price (qty-1, USD) | 6.95 | 6.50 | 7.20 | 6.40 | 5.50 | 5.80 |
Key Differentiators
- Higher clock-speed headroom within same package (vs PIC16C65A-04/PT)
- More program memory than sibling PIC16C64A (vs PIC16C64A-10/PT)
- Larger RAM and EEPROM than OTP predecessor (vs PIC16F877A-10/PT)
Design Notes
PIC16C65A uses One-Time Programmable (OTP) program memory - once a bit is programmed to '0' it cannot be erased or restored to '1'. Always develop and debug firmware on the flash-based PIC16F877A (same 44-pin TQFP footprint, same mid-range instruction set), then perform production programming on PIC16C65A only after firmware is fully validated. A single bug in production firmware can scrap an entire OTP wafer lot.
Place the 4 MHz to 10 MHz crystal or ceramic resonator within 5 mm of the OSC1 (pin 9) and OSC2 (pin 8) pins to minimize parasitic capacitance. Add 22-33 pF load capacitors from each oscillator pin to VSS, matched within 10% to maintain duty cycle symmetry. Use a ground guard ring around the oscillator traces to block digital switching noise from corrupting the clock waveform. Decoupling: place 100 nF ceramic + 10 uF tantalum bulk cap within 5 mm of every VDD/VSS pair (pins 11/10, 21/20, 31/30, 41/40) - four separate VDD/VSS pin pairs require independent decoupling.
Brown-out-reset (BOR) and power-on-reset (POR) must be enabled in the configuration word for reliable field operation - the PIC16C65A datasheet indicates BOR adds approximately 50-100 uA quiescent current. For battery-backed applications, the watchdog timer (WDT) with its dedicated internal RC oscillator (~18 ms nominal, postscaler adjustable to 2.25 s) provides fault recovery without external components. Sleep mode current is typically < 1 uA at 3V, suitable for battery-powered instrumentation when the MCU is duty-cycled.
PORTB pins RB0-RB7 have software-controlled weak pull-ups (single transistor, ~50-100 kohm) that are enabled by clearing the RBPU bit in the OPTION register - use these for switch-matrix inputs without external resistors, but note they cannot source more than 200 uA and are unsuitable for driving LEDs. PORTC high-current pins (RC0-RC7) can source/sink up to 25 mA per pin but total package dissipation is limited to 800 mW - derate to 20 mA per pin across multiple outputs simultaneously.
The 44-pin TQFP package has a thermal resistance of approximately 50-60 C/W (junction to ambient, per Microchip package thermal data) - at full 10 MHz operation with all I/O pins toggling, internal dissipation reaches 100-150 mW, well within the package rating. For sealed enclosures without airflow, ensure copper pour area on PCB reaches at least 1 square inch of continuous ground plane on the top layer for adequate heat spreading. Industrial-temperature variants (-I suffix) are rated -40C to +85C and should be specified for outdoor or under-hood installations.
Compliance Information
Lifecycle status is NRND per Microchip's 2026 product catalog. AEC-Q100 qualification not applicable - this is a general-purpose industrial/commercial MCU, not automotive-qualified. RoHS, REACH, lead-free, halogen-free, and conflict-minerals status not explicitly stated in the Verified Web Data and require manufacturer datasheet or compliance certificate review.
