PIC16C65A-10/PQ - 8-bit OTP MCU 7KB 33 I/O | Microchip
MPN: PIC16C65A-10/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.5 | $9.50 |
| 10 | $8.55 | $85.50 |
| 100 | $7.65 | $765.00 |
| 500 | $6.8 | $3,400.00 |
| 1,000 | $6.1 | $6,100.00 |
PIC16C65A-10/PQ Overview
A microcontroller (MCU) is an integrated circuit that combines a CPU core, program memory, RAM, and programmable peripheral I/O into a single chip, forming the lowest-tier decision-making element of an embedded system. Within the broader semiconductor taxonomy, an MCU belongs to integrated circuits > microcontrollers > 8-bit microcontrollers > CMOS RISC microcontrollers. OTP variants like the PIC16C65A are typically used in volume production where the firmware is fixed and re-programming is unnecessary, while EPROM/flash variants are reserved for development. The PIC16C65A sits in Microchip's mid-range PIC16 family, between PIC16C6X baseline and PIC16C7X enhanced peripherals.
Key features of the PIC16C65A-10/PQ include a power-on reset, brown-out detection (BOD), watchdog timer (WDT) with on-chip RC oscillator, code-protection bit, programmable code-protection, and four hardware interrupt sources. It provides three timer/counter modules (Timer0, Timer1, Timer2) supporting capture/compare/PWM operation, a USART serial port, and an 8-bit parallel slave port. The 33 I/O pins are grouped into five ports (PORTA through PORTE) with programmable direction registers, supporting direct LED drive, key matrix scanning, and analog comparator inputs via PORTE.
The PIC16C65A core implements a Harvard architecture with separate program and data buses, enabling simultaneous instruction fetch and operand access. Its CMOS process yields typical active current around 5 mA at 10 MHz and standby current below 5 uA, suitable for battery-backed industrial and consumer products. The OTP memory is programmed using Microchip's PM3 universal programmer or compatible gang programmers; once written, the bit cannot be erased, so OTP parts are final-state production parts.
Typical applications include industrial process controllers, motor drive front-ends, HVAC fan/pump controls, appliance controllers, automotive body modules, instrumentation front panels, and security alarm panels. The 33 I/Os allow direct keypad + LCD interface without external glue logic, while the USART enables RS-232/RS-485 communication with an external transceiver.
When designing with the PIC16C65A-10/PQ, ensure the supply stays within 4.0V-6.0V (this part is not 3.3V tolerant) and add a 100 nF decoupling capacitor close to VDD. Because this is an OTP device, a parallel production programmer strategy must be planned early to avoid scrapped PCBs if firmware revisions occur late in the design cycle.
This page synthesizes distributor pricing, drop-in alternatives within the same 44-pin QFP package, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16C65A-10/PQ — 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/PQ (same form factor and footprint) — differing in Package, RoHS Status, Timers, Program Memory Type, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C65A-10I/PQ
✅ Drop-In✓ In Stock
$5.2 / Unit
View Datasheet →PIC16C65A-10E/PQ
✅ Drop-In✓ In Stock
$9.75 / Unit
View Datasheet →PIC16C65A-04/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65A-20/PQ
✅ Drop-In✓ In Stock
$4.61 / Unit
View Datasheet →PIC16C64A-10/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65A-04I/P
✅ Drop-In✓ In Stock
$5.25 / Unit
View Datasheet →PIC16C65A-10/PQ Maximum Ratings & Electrical Characteristics
| Product Family | PIC16C6X (mid-range 8-bit MCU) |
| Core Architecture | 8-bit RISC, Harvard |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 bytes |
| Data EEPROM | 0 bytes (not present on PIC16C65A) |
| Maximum CPU Clock Frequency | 10 MHz |
| Instruction Throughput | 10 MIPS (1 instruction per clock cycle) |
| Supply Voltage (VDD) | 4.0 V to 6.0 V |
| Number of I/O Pins | 33 |
| Number of Timers | 3 (Timer0, Timer1, Timer2) |
| Capture/Compare/PWM Modules | 1 (CCP) |
| Serial Communication | USART (SCI) |
| Parallel Slave Port | Yes, 8-bit |
| Interrupts | 4 hardware sources |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Brown-Out Detection | Yes |
| Reset Sources | POR, BOR, WDT, MCLR |
| Instruction Set Size | 35 single-word instructions |
| Operating Temperature | 0C to +70C (commercial grade) |
| Package | 44-pin QFP (MQFP) |
| Terminal Form | GULL WING |
| Package Code | QFP, square |
| Mounting Type | Surface Mount |
PIC16C65A-10/PQ Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage input |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / analog input 3 / ADC reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 8 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 9 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 12 | VSS — Ground reference |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / CCP1 output |
| Pin 14 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 16 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 21 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 22 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 23 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 24 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 25 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 26 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 27 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 28 | VSS — Ground reference |
| Pin 29 | RE0/RD/AN5 — PORTE bit 0 / Parallel Slave Port read control / analog input 5 |
| Pin 30 | RE1/WR/AN6 — PORTE bit 1 / Parallel Slave Port write control / analog input 6 |
| Pin 31 | RE2/CS/AN7 — PORTE bit 2 / Parallel Slave Port chip select / analog input 7 |
| Pin 32 | VDD — Positive supply voltage (+5V) |
| Pin 33 | RB0/INT — PORTB bit 0 / external interrupt input |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3/PGM — PORTB bit 3 / low-voltage programming input |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock input |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data input/output |
| Pin 41 | VDD — Positive supply voltage (+5V) |
| Pin 42 | VSS — Ground reference |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C65A-10/PQ is suitable for 7 applications: Industrial Process Controllers, HVAC Fan and Pump Motor Control, Home Appliance Control Boards, Automotive Body and Accessory Modules, Security and Alarm Panel Controllers, Instrumentation Front Panels, LED Display and Sign Controllers.
Industrial Process Controllers
The PIC16C65A-10/PQ's 33 digital I/O pins and 4.0-6.0 V operation make it a strong fit for industrial process controllers driving relays, solenoids, and indicator lamps. With 7 KB of OTP program memory, the firmware can implement PID loop logic, keypad scanning, and 7-segment multiplexed displays without external glue logic. The USART interfaces to an external RS-485 transceiver for multi-drop industrial networks, while the 8-bit parallel slave port allows connection to a host PLC or HMI panel. The 10 MIPS instruction throughput ensures sub-millisecond control loop execution, critical for closed-loop temperature or pressure regulation. Brown-out detection and watchdog timer provide field reliability against supply transients common on factory floors.
Recommended
HVAC Fan and Pump Motor Control
In HVAC variable-speed fan and pump controllers, the PIC16C65A-10/PQ provides Timer0/Timer1/Timer2 plus a CCP module to generate PWM drive commands to an external IGBT/MOSFET driver. Its 33 I/O handle tachometer feedback, thermistor inputs, mode-switch buttons, and triac trigger outputs. The 4.0-6.0 V operation tolerates 5 V analog sensor rails common in HVAC boards. Because the device is OTP, firmware is locked at production and cannot be field-updated, fitting appliance OEMs that ship fixed-function controllers. The 192-byte RAM is sufficient for ramp tables and PID state, while 7 KB of code space supports state-machine plus soft-start logic.
Recommended
Home Appliance Control Boards
Washing machines, dishwashers, microwave ovens, and induction cooktops historically shipped with PIC16C65A-class controllers because the 33 I/O directly interface with keypads, LCD modules, motor drivers, and buzzer indicators. The 7 KB OTP holds menu logic, sensor filtering, and safety interlocks, while the parallel slave port supports a daughter keypad/touch board in modular appliance architectures. The commercial 0C to +70C range covers indoor kitchen environments, and the 5 mA active current keeps wall-adapter power budget comfortable. The PIC16C65A's 35-instruction RISC core compiles to extremely tight code, minimizing OTP size and per-unit cost in mass-production appliances.
Recommended
Automotive Body and Accessory Modules
The PIC16C65A-10/PQ appears in 1990s automotive body controllers, seat/window modules, and instrument cluster sub-controllers where its 33 I/O connect to switch matrix, lamp drivers, and stepper motor windings. The extended-temperature -10E/PQ variant is rated -40C to +125C and survives under-dash thermal stress. However, automotive designers today must migrate to AEC-Q100-qualified parts such as PIC16F877A-I/PQ or PIC18F46K22-I/PQ for new programs. The USART links the body controller to the vehicle's central gateway over LIN/CAN through an external transceiver, and the watchdog timer catches software lockups on noisy automotive buses.
Recommended
Security and Alarm Panel Controllers
Alarm control panels benefit from the PIC16C65A-10/PQ's 33 I/O to scan 8-16 zone inputs, drive a keypad, sound a siren driver, and communicate with a central station modem via the USART. The 7 KB OTP holds zone-trip logic, dialer sequences, and tamper-detection algorithms that are immutable in the field - ideal for UL-listed alarm panels where code tampering is a regulatory concern. The brown-out detector prevents lockup when backup batteries engage during AC loss, and the watchdog timer recovers from ESD-induced software hangs. The OTP also prevents easy reverse engineering of proprietary alarm protocols by competitors.
Recommended
Instrumentation Front Panels
Laboratory instruments and test equipment use the PIC16C65A-10/PQ as a front-panel controller handling rotary encoders, push buttons, multiplexed 7-segment displays, and the GPIB/RS-232 host interface. The 33 I/O easily cover a 32-key keypad matrix, the parallel slave port attaches to a host DSP or ASIC, and the USART links to a PC for SCPI command exchange. With 7 KB of OTP, the firmware holds state machines, calibration tables, and menu logic. The PIC16C65A's 10 MIPS throughput keeps display refresh and encoder debouncing responsive, and the 5 V tolerant I/O directly drives standard bipolar LED displays without level translation.
Recommended
LED Display and Sign Controllers
Moving-message signs and large LED matrix displays use the PIC16C65A-10/PQ to handle character ROM storage, scrolling algorithms, and row/column multiplexing. The 33 I/O pins can drive a small 5x7 LED matrix directly through external ULN2003 drivers, while the parallel slave port accepts bitmap data from an upstream PC or video processor. The 7 KB OTP holds fixed font tables and canned animation sequences that are immutable for warranty protection. With 10 MIPS throughput, the controller can refresh a 16-row display at 100+ Hz with no visible flicker. The PIC16C65A's OTP memory prevents unauthorized firmware cloning of OEM display content.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65A-10/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65A-10I/PQ | PIC16C65A-10E/PQ | PIC16C65A-04/PQ | PIC16C65A-20/PQ | PIC16C64A-10/PQ | PIC16C65A-04I/P |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin QFP (MQFP) | 44-pin QFP (MQFP) - same | 44-pin QFP (MQFP) - same | 44-pin QFP (MQFP) - same | 44-pin QFP (MQFP) - same | 44-pin QFP (MQFP) - same | 44-pin QFP (MQFP) - same |
| Program Memory (KB) | 7 | 7 | 7 | 7 | 7 | 3.5 | 7 |
| RAM (bytes) | 192 | 192 | 192 | 192 | 192 | 128 | 192 |
| Max CPU Clock (MHz) | 10 | 10 | 10 | 4 | 20 | 10 | 4 |
| Operating Temperature | 0C to +70C | -40C to +85C | -40C to +125C | 0C to +70C | 0C to +70C | 0C to +70C | -40C to +85C |
| I/O Pin Count | 33 | 33 | 33 | 33 | 33 | 33 | 33 |
| Parallel Slave Port | Yes (8-bit) | Yes | Yes | Yes | Yes | No | Yes |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM |
| Supply Voltage (V) | 4.0 to 6.0 | 4.0 to 6.0 | 4.0 to 6.0 | 4.0 to 6.0 | 4.0 to 6.0 | 4.0 to 6.0 | 4.0 to 6.0 |
Key Differentiators
- OTP memory type prevents field firmware tampering and reverse engineering (vs PIC16F877A-I/PQ)
- 33 I/O pins with integrated 8-bit parallel slave port (vs PIC16C64A-10/PQ)
- Mid-range PIC16 core with full USART and CCP peripherals (vs PIC16C62B-04/SO)
Design Notes
Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD pins (32 and 41 on the 44-pin QFP). The PIC16C65A has two VDD and three VSS pins; both VDD pins must be tied together on the PCB and both VSS pins to ground. Brown-out detection must be enabled in the configuration word for reliable reset behavior under supply droops. Operating voltage is 4.0-6.0 V; do NOT power from a 3.3 V rail as logic-high thresholds and ADC references will fail.
Because this is an OTP (One-Time Programmable) device, code cannot be erased or re-programmed after the first write. Always program a small batch of pre-production units and verify end-to-end functionality in-system before committing to volume programming - any firmware bug becomes a permanent scrapped PCB. Configuration word bits (oscillator type, watchdog enable, code protection, brown-out enable) MUST be set correctly during programming as they cannot be changed later. Use Microchip PM3 or MPLAB ICD2 with OTP adapter for programming.
Keep the 44-pin QFP oscillator traces (OSC1/OSC2) short and surrounded by ground guard ring to avoid EMC radiation. Place decoupling capacitors on every VDD pin with traces under 5 mm. PORTE pins used as analog inputs (RE0-RE2 / AN5-AN7) should be bypassed with 100 nF capacitors if switching noise is present, because these pins share the ADC mux. RB3 is shared with low-voltage programming - if used as output, ensure no driver contention during ICSP programming.
The PIC16C65A-10/PQ has no internal thermal sensor and is rated for commercial 0C to +70C ambient. The 44-pin QFP package has a thermal resistance of approximately 60 C/W - acceptable for typical 5 mA active / 5 uA standby operation. In enclosed industrial cabinets without airflow, derate junction temperature calculation: Tj = Ta + (Pd x theta_JA). At 5 mA x 5 V = 25 mW, self-heating is negligible but ensure ambient stays within spec for reliable brown-out and ADC reference behavior.
Compliance Information
Compliance information not present in Verified Web Data. The PIC16C65A is a legacy 1990s-era product; modern RoHS/REACH documentation may not be published. For automotive applications use the -10E/PQ variant which is rated to -40C to +125C but is NOT AEC-Q100 qualified - new automotive designs should use PIC16F877A-I/PQ or PIC18F46K22 with AEC-Q100.
