PIC16C65AT-20E/L - 8-Bit 20MHz OTP MCU 7KB | Microchip PLCC-44
MPN: PIC16C65AT-20E/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.5 | $11.50 |
| 10 | $10.2 | $102.00 |
| 100 | $8.95 | $895.00 |
| 500 | $7.8 | $3,900.00 |
| 1,000 | $6.95 | $6,950.00 |
PIC16C65AT-20E/L Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory (ROM/RAM), and programmable peripherals. Within the broader taxonomy, the PIC16C65A is a RISC microcontroller, which sits under the 8-bit MCU category, then the embedded processor family, then the semiconductor hierarchy. RISC (Reduced Instruction Set Computer) designs such as this one use a small set of single-cycle instructions to deliver predictable throughput and compact code density.
Key features include 35 single-word instructions (all single-cycle except program branches which are two cycles), DC to 20 MHz operating speed, 192-byte data RAM, 33 I/O pins, and integrated peripherals such as timers, a USART, and analog comparators. The 14-bit instruction width allows most instructions to encode a literal operand in a single word, simplifying compiler output.
The PIC16C65A uses a Harvard architecture with separate program and data buses, enabling simultaneous instruction fetch and operand access. This dual-bus design combined with the 8-bit ALU and 14-bit instruction word allows byte-oriented arithmetic with single-cycle execution, which is unusual for 8-bit parts and helps the device deliver roughly 5 MIPS at 20 MHz.
Typical applications include industrial control, automotive subsystems, sensor interfacing, embedded instrumentation, and legacy equipment maintenance. The automotive-grade 'E' temperature range (-40C to +125C) supports under-hood and other harsh-environment deployments.
When designing with this device, plan the firmware carefully because OTP memory cannot be reprogrammed; use a windowed or Flash variant such as PIC16F877 during development and migrate to the PIC16C65A for production. Ensure decoupling and oscillator layout follow Microchip midrange application notes to avoid EMC issues.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving procurement and engineering teams a single decision point.
Drop-in alternatives for PIC16C65AT-20E/L — 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 PIC16C65AT-20E/L (same form factor and footprint) — differing in Package, Program Memory Size, Program Memory Type, Operating Temperature, CCP Modules.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C65AT-20/PQ
✅ Drop-In✓ In Stock
$3.92 / Unit
View Datasheet →PIC16C65A-20I/L
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →PIC16C65A-20E/L
✅ Drop-In✓ In Stock
$6.2 / Unit
View Datasheet →PIC16C65A-20I/PQ
✅ Drop-In✓ In Stock
$8.62 / Unit
View Datasheet →PIC16F877A-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65AT-20E/L Maximum Ratings & Electrical Characteristics
| Family | PIC16C6X |
| Core | PIC 8-bit RISC |
| Architecture | Harvard, 14-bit instruction word |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 7 KB (4K x 14) |
| Data RAM | 192 bytes |
| Maximum Clock Frequency | 20 MHz |
| Instruction Set | 35 single-word instructions |
| Supply Voltage | 5 V |
| I/O Pins | 33 |
| Package | 44-pin PLCC (16.59 x 16.59 mm) |
| Operating Temperature | -40C to +125C (extended, 'E' grade) |
| Mounting Type | Surface Mount |
| Packaging Form | Tape & Reel ('T' suffix) |
PIC16C65AT-20E/L Pin Configuration
| Pin 1 | MCLR — Master Clear (Reset) input, active low |
| Pin 2 | RA0 — PORTA bit 0 / analog comparator input |
| Pin 3 | RA1 — PORTA bit 1 / analog comparator input |
| Pin 4 | RA2 — PORTA bit 2 / analog comparator reference |
| Pin 5 | RA3 — PORTA bit 3 / analog comparator input |
| Pin 6 | RA4 — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5 — PORTA bit 5 / analog comparator output |
| Pin 8 | RE0 — PORTE bit 0 / parallel slave port read control |
| Pin 9 | RE1 — PORTE bit 1 / parallel slave port write control |
| Pin 10 | RE2 — PORTE bit 2 / parallel slave port chip select |
| Pin 11 | VDD — Positive supply voltage (5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1 — Crystal oscillator input |
| Pin 14 | OSC2 — Crystal oscillator output |
| Pin 15 | RC0 — PORTC bit 0 / Timer1 oscillator |
| Pin 16 | RC1 — PORTC bit 1 / Timer1 oscillator |
| Pin 17 | RC2 — PORTC bit 2 / CCP1 output |
| Pin 18 | RC3 — PORTC bit 3 / USART clock |
| Pin 19 | RD0 — PORTD bit 0 / parallel slave port |
| Pin 20 | RD1 — PORTD bit 1 / parallel slave port |
| Pin 21 | RD2 — PORTD bit 2 / parallel slave port |
| Pin 22 | RD3 — PORTD bit 3 / parallel slave port |
| Pin 23 | RC4 — PORTC bit 4 / USART data input |
| Pin 24 | RC5 — PORTC bit 5 / USART data output |
| Pin 25 | RC6 — PORTC bit 6 / USART clock |
| Pin 26 | RC7 — PORTC bit 7 / USART data |
| Pin 27 | RD4 — PORTD bit 4 / parallel slave port |
| Pin 28 | RD5 — PORTD bit 5 / parallel slave port |
| Pin 29 | RD6 — PORTD bit 6 / parallel slave port |
| Pin 30 | RD7 — PORTD bit 7 / parallel slave port |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage (5V) |
| Pin 33 | RB0 — PORTB bit 0 / external interrupt |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3 — PORTB bit 3 |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6 — PORTB bit 6 / in-circuit debug clock |
| Pin 40 | RB7 — PORTB bit 7 / in-circuit debug data |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C65AT-20E/L is suitable for 6 applications: Industrial Process Control, Automotive Body and HVAC Modules, Sensor Signal Conditioning Nodes, Embedded Instrumentation, Motor Control Daughter Boards, Legacy Equipment Repair and Sustainment.
Industrial Process Control
The PIC16C65AT-20E/L fits industrial process-control PLCs and remote terminal units because its 33 digital I/O pins drive relay banks, opto-isolated inputs, and 7-segment displays simultaneously without external mux. Its 20 MHz core provides up to 5 MIPS, comfortably executing PID loops at 10 ms update rates on multiple loops concurrently. The extended -40C to +125C temperature grade survives unheated cabinet deployments, and the OTP memory locks firmware against unauthorized field updates. Pair with a MAX485 for RS-485 and an external 12-bit ADC such as MCP3204 for analog sensor reading, using PORTA comparator pins for value-sensing alarm inputs.
Recommended
Automotive Body and HVAC Modules
The PIC16C65AT-20E/L is well matched to automotive body controllers and HVAC control modules, where its 33 I/O pins interface directly to switch panels, motor drivers, and indicator LEDs. The E-grade temperature window (-40C to +125C) survives under-dash thermal cycling, and the 5 MIPS throughput executes multi-zone climate control algorithms and serial communication with the body controller area network simultaneously. The OTP memory prevents end-user firmware tampering. Connect via MCP2515 CAN transceiver for OBD-II integration; for newer designs, migrate to PIC18F variants with integrated CAN.
Recommended
Sensor Signal Conditioning Nodes
The PIC16C65AT-20E/L serves as a smart front-end for sensor signal conditioning, particularly for bridge-type sensors, thermistors, and 4-20 mA loops. Its 192-byte RAM buffers acquired samples before serial transmission, while the analog comparators on PORTA provide threshold detection for alarm outputs. Operating at 20 MHz with predictable single-cycle instruction timing, the device delivers deterministic sample rates essential for vibration and pressure monitoring. Pair with INA128 instrumentation amplifier for low-level bridge sensors and MAX31865 RTD-to-digital converter for precision temperature.
Recommended
Embedded Instrumentation
For embedded instrumentation such as handheld multimeters, panel meters, and bench-top data loggers, the PIC16C65AT-20E/L provides the right balance of I/O count, throughput, and cost. Its 33 I/O drive LCD segments directly via multiplexing, interface matrix keypads, and stream digitized measurements through the USART to a host PC. The 7 KB OTP program memory holds complete calibration routines plus user interface code, while the extended temperature range ensures accuracy in outdoor or industrial environments.
Recommended
Motor Control Daughter Boards
The PIC16C65AT-20E/L is well suited to brushed DC and stepper motor control daughter boards in industrial automation. Its PWM-capable CCP modules drive H-bridge MOSFET drivers such as the IR2104, while the 20 MHz core computes velocity profiles and current loops in real time. The 33 I/O handle end-stop inputs, encoder feedback, and enable/discrete logic simultaneously. OTP memory locks validated motor parameters and proprietary commutation algorithms in production units.
Recommended
Legacy Equipment Repair and Sustainment
Because the PIC16C65AT-20E/L remains the canonical MCU inside many legacy industrial controllers, vending machines, and HVAC systems shipped in the late 1990s, it is in continuous demand for repair and sustainment programs. Authorized aftermarket distributors stock the part in tape-and-reel format, and the Microchip PIC16C6X family datasheet provides full documentation. For new designs avoid the OTP variant; for legacy maintenance, source from authorized suppliers or migrate firmware to PIC16F877A with attention to pin remapping on PLCC-44.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65AT-20E/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65A-20I/L | PIC16C65A-20E/L | PIC16F877A-I/L |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin PLCC (L) | 44-pin PLCC (L) - same | 44-pin PLCC (L) - same | 44-pin PLCC (L) - same footprint, different pin assignments |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 14 KB Flash |
| Data RAM | 192 bytes | 192 bytes | 192 bytes | 368 bytes |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| I/O Pins | 33 | 33 | 33 | 33 |
| Temperature Grade | Extended (-40C to +125C) | Industrial (-40C to +85C) | Extended (-40C to +125C) | Industrial (-40C to +85C) |
| ADC | None (2 analog comparators) | None (2 analog comparators) | None (2 analog comparators) | 8-channel 10-bit ADC |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Active |
Key Differentiators
- Extended industrial temperature grade with tape-and-reel packaging (vs PIC16C65A-20I/L)
- Compact OTP form factor with industrial safety margin (vs PIC16C65AT-20/PQ)
- Migration to Flash-based PIC16F877A for development flexibility (vs PIC16F877A-I/L)
Design Notes
Estimated: OTP program memory on PIC16C65A cannot be erased or rewritten. For development cycles use PIC16F877A or PIC16F877 in the same 44-PLCC footprint and migrate verified firmware to OTP for production. Windowed PIC16C65A-20/JW variants exist for low-volume prototyping but require a UV eraser. Confirm device-marking decals match the suffix ordering code before programming to avoid bricking inventory.
Place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pair (pins 11/12 and 31/32) to suppress switching transients on the 5V rail. Add a 10 uF bulk tantalum or ceramic capacitor at the board supply input. The PIC16C65A draws approximately 15 mA active at 20 MHz and under 1 uA in sleep mode, so power sequencing with brown-out is generally unnecessary unless operating near the 4.5V minimum supply voltage.
Keep crystal traces (OSC1 pin 13, OSC2 pin 14) short, with the load capacitors placed within 5 mm of the device pins and a ground guard ring around the oscillator traces to reduce EMI pickup. Avoid routing signal traces under the crystal or its capacitors. For high-noise environments, add a series resistor in the MCLR line (pin 1) to limit ESD injection and prevent spurious resets.
The 44-pin PLCC socket adds approximately 3 mm of lead inductance compared to surface-mount PLCC land patterns. For high-speed or sensitive analog designs, solder the part directly to the PCB or use a low-profile PLCC socket. PORTA pins double as analog comparator inputs; route them away from PWM outputs and digital switching signals to minimize cross-coupling into the comparator threshold voltage.
Compliance Information
RoHS and lead-free status not specified in verified web data; PIC16C65A family was originally launched before widespread RoHS transition, so non-RoHS versions may exist. For new RoHS-compliant designs use PIC16F877A. AEC-Q100 not applicable to general-purpose 8-bit MCU; automotive qualification is via customer system-level testing.
