PIC16C65A-04E/PT - 8-bit PIC MCU 7KB OTP 4MHz 44-TQFP | Microchip
MPN: PIC16C65A-04E/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.2 | $162.00 |
| 100 | $13.85 | $1,385.00 |
| 500 | $11.95 | $5,975.00 |
| 1,000 | $10.4 | $10,400.00 |
PIC16C65A-04E/PT Overview
The PIC16C65A belongs to the 8-bit microcontroller (MCU) category, a class of single-chip microcontrollers that integrate CPU core, program memory, data RAM, peripherals and I/O into one package. Within that hierarchy the part sits under 8-bit MCU -> microcontroller -> embedded processor -> semiconductor. PIC16C-series devices target low-cost, deterministic embedded control and remain popular where engineers need rapid interrupt response, simple instruction set, and decades of mature toolchain support from MPLAB IDE, MPASM assembler, and Hi-Tech C compilers.
Key features include 192 bytes of general-purpose RAM, 33 digital I/O pins, a programmable code-protection scheme, an 8-bit timer/counter, a watchdog timer, and on-chip power-on reset / brown-out reset circuitry. Peripherals include USART, parallel slave port, capture/compare/PWM modules, and synchronous serial port hardware. The architecture supports direct, indirect and relative addressing modes plus a hardware multiply assist, giving the PIC16C65A strong interrupt latency performance for real-time control.
Typical applications include industrial process control, instrumentation front-ends, motor control front-ends, building automation, low-power sensor hubs, and legacy embedded systems that require an OTP-programmed controller with extended-temperature qualification. Designers migrating from windowed EPROM parts often choose PIC16C65A-04E variants (E = extended temperature) for harsh-environment deployments.
When designing with this device, note that the '04' suffix denotes 4 MHz maximum clock and the 'E' suffix denotes the extended -40C to +125C temperature grade. The PT suffix marks the 44-pin TQFP (10x10 mm) package, which requires 1.0 mm PCB pad pitch. The PIC16C65A-04E/PT is OTP, so firmware must be fully validated before programming; windowed JW-package variants exist for prototype development.
This page synthesizes distributor stock, drop-in 44-TQFP pin-compatible alternatives, application circuit guidance, and lifecycle notes not found in the manufacturer datasheet alone, providing a single reference for engineers evaluating PIC16C65A-04E/PT for new designs or maintenance of legacy systems.
Drop-in alternatives for PIC16C65A-04E/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 PIC16C65A-04E/PT (same form factor and footprint) — differing in Operating Temperature Range, RAM Size, Package, Program Memory Size, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C64A-04E/PT
✅ Drop-In✓ In Stock
$7.35 / Unit
View Datasheet →PIC16C64AT-04E/PT
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →PIC16C64AT-10E/PT
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC16C64AT-20E/PT
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC16C65A-04/P
✅ Drop-In✓ In Stock
$8.1 / Unit
View Datasheet →PIC16C65A-04E/PT Maximum Ratings & Electrical Characteristics
| Series | PIC16C |
| Core | 8-bit PIC16 RISC |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14) |
| RAM Size | 192 x 8 bytes |
| Number of I/O Pins | 33 |
| Supply Voltage (Vcc/Vdd) | 4 V to 6 V |
| Maximum Clock Frequency | 4 MHz |
| Instruction Execution Time | 200 ns |
| Number of Instructions | 35 single-word |
| Operating Temperature Range | -40C to +125C (Extended, 'E' suffix) |
| Package | 44-pin TQFP (10x10 mm, 'PT' suffix) |
| Mounting Type | Surface Mount |
| Peripherals | USART, PSP, SSP, PWM, 8-bit Timer, WDT, BOR |
PIC16C65A-04E/PT Pin Configuration
| Pin 1 | RA0/AN0 — Port A bit 0 / Analog input 0 |
| Pin 2 | RA1/AN1 — Port A bit 1 / Analog input 1 |
| Pin 3 | RA2/AN2 — Port A bit 2 / Analog input 2 |
| Pin 4 | RA3/AN3/VREF — Port A bit 3 / Analog input 3 / VREF |
| Pin 5 | RA4/T0CKI — Port A bit 4 / Timer 0 clock input |
| Pin 6 | RA5/AN4/SS — Port A bit 5 / Analog input 4 / Slave select |
| Pin 7 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 8 | OSC2/CLKOUT — Oscillator output |
| Pin 9 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer 1 oscillator out / T1 clock in |
| Pin 10 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer 1 oscillator in / CCP2 |
| Pin 11 | RC2/CCP1 — Port C bit 2 / Capture-Compare-PWM 1 |
| Pin 12 | RC3/SCK/SCL — Port C bit 3 / SPI SCK / I2C SCL |
| Pin 13 | RC4/SDI/SDA — Port C bit 4 / SPI SDI / I2C SDA |
| Pin 14 | RC5/SDO — Port C bit 5 / SPI SDO |
| Pin 15 | RC6/TX/CK — Port C bit 6 / USART TX / USART CK |
| Pin 16 | RC7/RX/DT — Port C bit 7 / USART RX / USART DT |
| Pin 17 | GND — Ground |
| Pin 18 | VDD — Positive supply |
| Pin 19 | RB0/INT — Port B bit 0 / External interrupt |
| Pin 20 | RB1 — Port B bit 1 |
| Pin 21 | RB2 — Port B bit 2 |
| Pin 22 | RB3/PGM — Port B bit 3 / LVP programming |
| Pin 23 | RB4 — Port B bit 4 |
| Pin 24 | RB5 — Port B bit 5 |
| Pin 25 | RB6/PGC — Port B bit 6 / ICSP clock |
| Pin 26 | RB7/PGD — Port B bit 7 / ICSP data |
| Pin 27 | RD0/PSP0 — Port D bit 0 / Parallel slave port bit 0 |
| Pin 28 | RD1/PSP1 — Port D bit 1 / Parallel slave port bit 1 |
| Pin 29 | RD2/PSP2 — Port D bit 2 / Parallel slave port bit 2 |
| Pin 30 | RD3/PSP3 — Port D bit 3 / Parallel slave port bit 3 |
| Pin 31 | RD4/PSP4 — Port D bit 4 / Parallel slave port bit 4 |
| Pin 32 | RD5/PSP5 — Port D bit 5 / Parallel slave port bit 5 |
| Pin 33 | RD6/PSP6 — Port D bit 6 / Parallel slave port bit 6 |
| Pin 34 | RD7/PSP7 — Port D bit 7 / Parallel slave port bit 7 |
| Pin 35 | RE0/RD — Port E bit 0 / Parallel port read strobe |
| Pin 36 | RE1/WR — Port E bit 1 / Parallel port write strobe |
| Pin 37 | RE2/CS — Port E bit 2 / Parallel port chip select |
| Pin 38 | VSS — Ground (TQFP analog/digital) |
| Pin 39 | VDD — Positive supply |
| Pin 40 | NC — Not connected |
| Pin 41 | NC — Not connected |
| Pin 42 | NC — Not connected |
| Pin 43 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 44 | NC — Not connected |
Typical Applications
PIC16C65A-04E/PT is suitable for 6 applications: Industrial Process Control, Instrumentation Front-End, Motor Control Front-End, Building Automation Controller, Low-Power Sensor Hub, Legacy Embedded Systems Maintenance.
Industrial Process Control
The PIC16C65A-04E/PT fits industrial process control applications because of its 33 digital I/O lines, USART and parallel slave port peripherals, 192 bytes of RAM, and extended -40C to +125C temperature grade. The 7 KB OTP program memory holds typical PID-loop, valve-actuator, and sensor-multiplexing firmware. Deterministic 200 ns instruction execution at 4 MHz gives predictable interrupt latency for closed-loop control cycles, while on-chip power-on reset and brown-out reset protect against supply transients on factory floors.
Recommended
Instrumentation Front-End
The PIC16C65A-04E/PT works as an instrumentation front-end controller thanks to its parallel slave port for high-speed ADC interfacing, 8-bit timer/counter for precise sample timing, and USART for digital telemetry output. Its 35 single-word instruction set keeps firmware compact within 7 KB of OTP, allowing scan routines, calibration tables, and LCD driver code on a single chip. The extended temperature rating supports bench, laboratory, and outdoor measurement environments where consumer-grade parts fail.
Recommended
Motor Control Front-End
The PIC16C65A-04E/PT handles motor control front-end tasks such as PWM generation, Hall-sensor input decoding, and current-loop feedback processing. The on-chip capture/compare/PWM module generates brushed-DC and unipolar stepper drive waveforms, while 33 I/O lines accommodate multiple sensor inputs and bridge-driver control signals. Its deterministic 200 ns instruction execution at 4 MHz keeps PWM jitter within tolerance, and the extended -40C to +125C grade suits motor enclosures that experience thermal stress.
Recommended
Building Automation Controller
The PIC16C65A-04E/PT fits building automation controllers such as HVAC zone controllers, lighting panels, and access-control nodes. Its 192 bytes of RAM holds scheduling tables and active-zone state machines, while the USART interfaces with central management networks. The PIC RISC architecture's deterministic interrupt response ensures clean timing for relay de-bouncing, occupancy-sensor polling, and TRIAC zero-crossing control, with 7 KB of OTP accommodating typical automation firmware.
Recommended
Low-Power Sensor Hub
The PIC16C65A-04E/PT operates as a low-power sensor hub in remote monitoring applications where its 33 I/O lines multiplex multiple analog and digital sensors and its USART outputs telemetry. The 4 MHz clock keeps dynamic power dissipation low, and the 4-6 V supply range supports battery and bus-powered deployments. PIC16C-series OTP devices are well-suited to sensor hubs that must remain in service for decades without firmware updates.
Recommended
Legacy Embedded Systems Maintenance
The PIC16C65A-04E/PT is used to maintain legacy embedded systems that were originally built on this exact part. Maintenance, repair, and overhaul activities benefit from the extended -40C to +125C temperature rating, proven PIC RISC architecture, and identical pinout across the PIC16C6X family. Engineers sustaining field-deployed equipment use the same development tools (MPLAB IDE, MPASM assembler, Hi-Tech C compiler) that were used when the system was originally designed.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65A-04E/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C64A-04E/PT | PIC16C64AT-04E/PT | PIC16C64AT-10E/PT |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin TQFP | 44-pin TQFP - same | 44-pin TQFP - same | 44-pin TQFP - same |
| Core | 8-bit PIC16 RISC | 8-bit PIC16 RISC | 8-bit PIC16 RISC | 8-bit PIC16 RISC |
| Program Memory | 7 KB OTP (4K x 14) | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| RAM Size | 192 bytes | 128 bytes (-33%) | 128 bytes (-33%) | 128 bytes (-33%) |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 10 MHz (+150%) |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C |
| I/O Pins | 33 | 33 | 33 | 33 |
Key Differentiators
- Highest RAM in 44-TQFP PIC16C6X family (vs PIC16C64A-04E/PT)
- More peripherals than PIC16C64A family (vs PIC16C64AT-04E/PT)
- Lower maximum clock than newer T-suffix variants (vs PIC16C64AT-10E/PT)
Design Notes
PIC16C65A-04E/PT is OTP (one-time programmable), so any firmware bug becomes permanent after programming. Verify code in a windowed PIC16C65A-JW prototype before committing to OTP. Also note: the /PT (TQFP) pinout differs from the /P (PDIP) variant - never assume pin numbers are interchangeable between the two packages. Confirm VDD/VSS pair count: the 44-TQFP has two VDD and two VSS pins, all of which must be decoupled for stable operation.
Place a 100 nF decoupling capacitor close to each VDD/VSS pair (4 total on 44-TQFP) plus a single 10 uF bulk capacitor on the supply rail. The PIC16C65A draws up to 25 mA at 4 MHz / 5 V; reserve 50 mA supply headroom for I/O switching transients. For battery-powered designs, use the PIC16C65A's SLEEP instruction and watchdog timer to drop quiescent current below 4 uA typical. Brown-out reset should be enabled in configuration fuses for industrial deployments.
Route the 4 MHz crystal traces symmetrically with short, equal-length paths and a ground guard ring to minimize EMI. Place the MCLR pull-up (typically 10 kOhm) within 5 mm of pin 1 to avoid spurious resets. The 33 I/O lines can drive up to 20 mA per pin (sink/source, but not simultaneously); cluster high-current drivers (relays, LEDs) near the supply pins to minimize ground bounce. Keep analog inputs RA0-RA5 away from switching signals for clean ADC readings.
Compliance Information
RoHS/REACH status must be verified from lot-specific manufacturer documentation because PIC16C65A-04E/PT was released before industry-wide RoHS adoption. The PT (TQFP) lead-free finish is typically compliant but date-code sensitive.
