PIC16C65A-04/P - 8-Bit 4MHz 7KB OTP MCU 40-PDIP | Microchip
MPN: PIC16C65A-04/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.19 | $12.19 |
| 10 | $11.45 | $114.50 |
| 100 | $10.18 | $1,018.00 |
| 500 | $9.05 | $4,525.00 |
| 1,000 | $8.1 | $8,100.00 |
PIC16C65A-04/P Overview
What is an OTP microcontroller? An OTP (one-time-programmable) microcontroller is a class of embedded controller in which the on-chip program memory can be written only once by the user. OTP MCUs sit in the hierarchy of microcontrollers between mask-ROM parts (factory-programmed, lowest cost at high volume) and Flash-based parts (rewritable in-circuit). Because they require no quartz window for UV erasure, OTP packages are cheaper to produce and physically smaller, which is why PIC16C65A-04/P is offered in the low-cost plastic PDIP-40 form factor. In the modern product hierarchy, OTP parts are a subset of one-time-programmable memory MCUs, which themselves sit under microcontrollers -> embedded controllers -> semiconductor ICs.
Key specifications of the PIC16C65A-04/P include 4 MHz maximum clock (the -04 speed grade), 200 ns instruction cycle, 35 single-word RISC instructions, 8-level deep hardware stack, 14-bit instruction word, 8-bit data path, 8-channel 8-bit ADC, two 8-bit timers plus one 16-bit timer, USART, SSP, and two CCP modules. Power supply range is 2.5 V to 6.0 V; the device operates across commercial (0 °C to +70 °C) and industrial (-40 °C to +85 °C) temperature ranges, with typical supply current of <2 mA at 5 V / 4 MHz and less than 1 µA in sleep mode.
Architecture-wise, the PIC16C65A is built on a Harvard RISC core that fetches instructions in a single cycle (except program branches, which take two cycles). This is the same family as the PIC16C66 and PIC16C67, sharing peripheral set and pinout in the 40-pin PDIP package, with the -A silicon revision adding improvements in oscillator robustness and ADC linearity versus the original PIC16C65. The -04 speed grade is the 4 MHz part, complemented by -10 (10 MHz) and -20 (20 MHz) grades in the same family.
Typical applications include industrial control logic, motor drive interfacing, instrumentation front-ends, HVAC controllers, security and access panels, automotive body electronics, embedded data acquisition, and any 8-bit control loop that needs ADC, PWM, and serial communication on a single low-cost chip. The 40-pin PDIP form factor makes it convenient for through-hole prototyping, breadboarding, educational kits, and legacy maintenance designs where the same socket pattern must be preserved across product revisions.
A key design consideration: because this is an OTP part, firmware bugs cannot be patched in the field - designers must validate code on a windowed (JW) or Flash sibling (PIC16F77) before committing to the OTP build. Also note the A-suffix in PIC16C65A denotes the second die revision, which has minor register differences versus the original PIC16C65 (revocation of the PCON<POR> bit and revised oscillator startup).
This page synthesizes distributor pricing, verified same-family and cross-family drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C65A-04/P — 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-04/P (same form factor and footprint) — differing in Package, RoHS Status, Timers, ADC, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F74-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F77-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65A-04E/P
✅ Drop-In✓ In Stock
$4.85 / Unit
View Datasheet →PIC16C65A-10/P
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →PIC16C65A-20/P
✅ Drop-In✓ In Stock
$3.85 / Unit
View Datasheet →PIC16C65A/JW
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C65A-04/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 8-bit RISC |
| Program Memory Size | 7 KB (4K x 14) OTP |
| RAM Size | 192 bytes |
| EEPROM Data Memory | 0 bytes (none on die) |
| Maximum CPU Clock | 4 MHz |
| Instruction Cycle | 200 ns |
| Instruction Word Width | 14 bits |
| Supply Voltage Range | 2.5 V to 6.0 V |
| I/O Pins | 33 |
| Timers | Timer0 (8-bit), Timer1 (16-bit), Timer2 (8-bit) |
| ADC | 8-bit, 8 channels |
| Communication Peripherals | USART, SSP (SPI / I2C) |
| CCP Modules | 2 |
| Operating Temperature Range | 0 °C to +70 °C (commercial) / -40 °C to +85 °C (industrial) |
| Package | 40-PDIP (0.600 in, 15.24 mm) |
| Mounting Type | Through-Hole |
| MSL Level | 1 (unlimited) |
| RoHS Status | Compliant |
PIC16C65A-04/P Pin Configuration
| Pin 1 | MCLR/VPP — Master clear (reset) input / programming voltage |
| 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 VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input (open-drain) |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / parallel-port read / analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / parallel-port write / analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / parallel-port chip select / analog input 7 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground |
| Pin 13 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 (PWM/capture/compare) |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — PORTD bit 0 / parallel slave port bit 0 |
| Pin 20 | RD1/PSP1 — PORTD bit 1 / parallel slave port bit 1 |
| Pin 21 | RD2/PSP2 — PORTD bit 2 / parallel slave port bit 2 |
| Pin 22 | RD3/PSP3 — PORTD bit 3 / parallel slave port bit 3 |
| Pin 23 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / parallel slave port bit 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / parallel slave port bit 5 |
| Pin 29 | RD6/PSP6 — PORTD bit 6 / parallel slave port bit 6 |
| Pin 30 | RD7/PSP7 — PORTD bit 7 / parallel slave port bit 7 |
| Pin 31 | VSS — Ground |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3/PGM — PORTB bit 3 / low-voltage programming |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC16C65A-04/P is suitable for 6 applications: Industrial Control Logic, HVAC and Building Automation, Security and Access Control Panels, Educational Microcontroller Trainer Boards, Motor Drive and PWM Control, Embedded Data Acquisition Front-End.
Industrial Control Logic
The PIC16C65A-04/P is well matched to industrial control panels because it combines 33 digital I/O, two CCP modules for PWM motor control, an 8-channel 8-bit ADC for sensor reading, and a USART for host communication in a single 40-PDIP chip. At 5 V and 4 MHz it dissipates roughly 10 mW, which is acceptable inside sealed enclosures, and the industrial temperature grade (-40 °C to +85 °C) covers factory-floor environments. The OTP memory and through-hole package make it a cost-effective, single-sourced solution for high-volume conveyor, valve, and pump controllers where firmware is locked at production time.
Recommended
HVAC and Building Automation
HVAC controller boards benefit from PIC16C65A-04/P's combination of three timers, two CCP PWM channels, and an 8-bit ADC for reading thermistor temperature sensors. The 4 MHz clock is sufficient for slow control loops such as fan-speed PWM and damper actuation, while the USART links to a network of slave sensors or a building-management gateway. With supply current under 2 mA at 5 V and less than 1 µA in sleep, this part suits mains-powered thermostat and zone-controller designs that prioritize standby efficiency. The 40-PDIP form factor allows hand-repair in field-installed equipment.
Recommended
Security and Access Control Panels
Security alarm panels and access-control keypads need reliable 8-bit processing for keypad scanning, magnetic-door sensor monitoring, siren-driver PWM, and serial reporting. The PIC16C65A-04/P's 33 I/O pins handle a 4x4 matrix keypad plus reed-switch inputs without external mux chips, and its USART interfaces to dialer or GSM modules. OTP memory prevents firmware tampering and reverse-engineering of secure code, an advantage over Flash parts in security deployments. The industrial temperature range and the 2.5 V to 6.0 V supply tolerance cover battery-backup transients during AC brown-out.
Recommended
Educational Microcontroller Trainer Boards
Universities and training centers have standardized on the PIC16C65A-04/P 40-PDIP package because the through-hole form factor is breadboard-friendly and can be socketed, allowing students to swap chips between labs. The 35-instruction RISC core and 4 MHz clock are slow enough that students can step through assembly code on an emulator and observe peripheral register changes, while the integrated ADC, USART, and PWM modules expose the full PIC16C6x peripheral set in a single part. OTP forces good engineering discipline: code is locked, students must revalidate before re-programming.
Recommended
Motor Drive and PWM Control
The two CCP modules on PIC16C65A-04/P generate complementary PWM outputs suitable for low-side or half-bridge DC motor drivers up to a few hundred Hz, while Timer2 provides the PWM time base. At 5 V and 4 MHz the PWM resolution is roughly 8 bits, which is more than enough for fan speed, pump flow, and solenoid duty-cycle control in white-goods and small-appliance products. The integrated 8-channel ADC reads back motor current via shunt amplifiers, and the USART reports telemetry to a host controller. OTP locking prevents field firmware modification, locking in safety-approved control algorithms.
Recommended
Embedded Data Acquisition Front-End
Cost-sensitive data loggers and instrumentation front-ends use the PIC16C65A-04/P to digitize up to 8 analog channels at 8-bit resolution, timestamp the samples with one of the three on-chip timers, and stream the results over USART to a host PC or industrial network. The 4 MHz clock supports ADC conversion rates up to ~50 ksps aggregate when the ADC clock is set to the recommended Fosc/16. OTP locking suits fixed-function instruments that ship with the same calibration firmware for years, and the 40-PDIP socket is convenient for field-replacement maintenance.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65A-04/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F74-I/P | PIC16F77-I/P | PIC16C65A-04E/P | PIC16C65A-10/P |
|---|---|---|---|---|---|
| Package | 40-PDIP (0.600 in) | 40-PDIP (0.600 in) - same | 40-PDIP (0.600 in) - same | 40-PDIP (0.600 in) - same | 40-PDIP (0.600 in) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | OTP (7 KB / 4K x 14) | Flash (7 KB) | Flash (14 KB) | OTP (7 KB) | OTP (7 KB) |
| Maximum CPU Clock | 4 MHz | 20 MHz | 20 MHz | 4 MHz | 10 MHz |
| RAM | 192 B | 192 B | 368 B | 192 B | 192 B |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Temperature Grade | Commercial 0 °C to +70 °C | Industrial -40 °C to +85 °C | Industrial -40 °C to +85 °C | Extended -40 °C to +125 °C | Commercial 0 °C to +70 °C |
| Field Reprogrammable | No (OTP) | Yes (Flash, ICSP) | Yes (Flash, ICSP) | No (OTP) | No (OTP) |
| Estimated Unit Price @ 1 pc | $12.19 | approximately $7-9 | approximately $9-11 | approximately $14-16 | approximately $13-15 |
Key Differentiators
- Flash-based in-circuit reprogrammability (vs PIC16C65A-04/P (self))
- Extended temperature range for harsh environments (vs PIC16C65A-04E/P)
- Higher speed grade for timing-sensitive loops (vs PIC16C65A-20/P)
Design Notes
Estimated: do not migrate code from PIC16C65 to PIC16C65A-04/P without reviewing the PCON register. According to the Microchip PIC16C65A datasheet errata, the POR (power-on-reset) bit semantics on the A-revision differ from the original PIC16C65. Code that polls the POR flag may need adjustment. Also, because the part is OTP, bugs in production firmware cannot be patched in the field - always validate on a windowed PIC16C65A/JW or Flash sibling PIC16F77 before committing the OTP build.
The PIC16C65A-04/P's analog supply (VDD) and digital supply share the same pin on the 40-PDIP package, so place a 100 nF decoupling capacitor within 5 mm of pin 11 and pin 32, with a bulk 10 µF tantalum on the VDD rail. AVSS and VSS are tied together internally; for ADC accuracy, route the analog inputs (RA0-RA5, RE0-RE2) on a separate analog ground pour that joins the digital ground at a single point near the VDD pin. The ADC's reference voltage defaults to VDD, so if the supply is noisy, add a 4.096 V MCP1541 reference to RA3/VREF+ for improved conversion linearity.
Estimated: at 4 MHz oscillator and TTL-level loading, keep OSC1/OSC2 traces shorter than 12 mm and shield them with a ground guard ring to avoid EMI pickup that can shift the USART baud rate. The MCLR/VPP pin (pin 1) should have a 10 kΩ pull-up to VDD and a 100 nF capacitor to ground to form the standard Microchip reset circuit; the MCLR trace should not be routed near high-current switching nodes. PORTB internal weak pull-ups are enabled by clearing the RBPU bit, which lets you drive switch inputs without external resistors.
The PIC16C65A-04/P in 40-PDIP is a low-power CMOS device dissipating well under 100 mW even at full 4 MHz / 5 V operation, so thermal management is rarely a concern. However, in enclosed industrial cabinets with ambient above 70 °C, derate supply voltage to 4.5 V and switch the oscillator to a slower 1 MHz resonator to keep junction temperature below the +125 °C absolute maximum.
Compliance Information
RoHS and REACH compliance per DigiKey and Mouser product pages. AEC-Q100 is not applicable for a commercial 8-bit MCU - for AEC-Q100 qualified alternatives, see PIC16F77-I/P industrial-grade variant. Conflict-minerals compliance per Microchip supplier declaration.
