PIC16C64A-20/PQ - 20MHz 8-bit CMOS MCU 3.5KB EPROM | Microchip
MPN: PIC16C64A-20/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.6 | $6.60 |
| 10 | $6.2 | $62.00 |
| 100 | $5.85 | $585.00 |
| 500 | $5.5 | $2,750.00 |
| 1,000 | $5.2 | $5,200.00 |
PIC16C64A-20/PQ Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program memory, RAM, and programmable peripherals. It belongs to the product hierarchy: microcontroller -> embedded processor -> integrated circuit -> semiconductor. The PIC16C6X family specifically targets cost-sensitive embedded applications requiring deterministic instruction execution, low power consumption, and compact code density. The PIC16C64A combines this RISC CPU with parallel ports, timers, and a USART, suitable for control loops, sensor interfacing, and human-machine interface designs.
Key features include a 20 MHz maximum operating frequency, wide 2.5 V to 6.0 V supply range, low-power consumption (15 uA typical at 5 V / 4 MHz and 1 uA at 3 V / 32 kHz), and fully static design that allows the clock to be stopped without losing register state. Program memory is 3.5 KB OTP EPROM, providing one-time field programmability through Microchip's standard device programmers. The 33 I/O pins support digital I/O with individual direction control, while on-chip peripherals include timers and a synchronous/asynchronous serial port (USART/SCI).
The architecture employs a Harvard-style separate program and data buses, with a 14-bit instruction word and 8-bit data path. The 8-level deep hardware stack supports subroutines and interrupts without external memory, while the 2K x 14 instruction-word program memory (3.5 KB total with configuration bits) maps directly to the device's 35-instruction opcode set, enabling very compact assembly code and predictable real-time response.
Typical applications include industrial control systems, automotive body electronics, appliance controllers, security and access control panels, and sensor-based measurement instruments. The device is widely used in legacy designs and replacement scenarios where proven PIC16C6X firmware is preserved without redevelopment. The -20 speed grade and /PQ package make this variant particularly suited for surface-mount manufacturing lines where commercial temperature grade (0C to +70C) and 20 MHz throughput are required.
When designing with this device, note that OTP EPROM cannot be erased in-circuit; for prototyping or code-iteration workflows, a windowed CERDIP package variant (such as PIC16C64A-20/P) is preferable. The 44-pin MQFP package requires careful PCB layout with adequate ground plane and short trace lengths to the crystal and decoupling capacitors. Operating voltage should be maintained within 2.5 V to 6.0 V, with Vdd decoupling placed within 1 cm of the supply pin per Microchip's recommended layout practices.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone. The content below is curated for component engineers evaluating the PIC16C64A-20/PQ for new designs, lifecycle substitution, or maintenance of legacy systems.
Drop-in alternatives for PIC16C64A-20/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 PIC16C64A-20/PQ (same form factor and footprint) — differing in Operating Temperature Range, Package, Timers, Program Memory Size, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C65B-20/PQ
✅ Drop-In✓ In Stock
$7.32 / Unit
View Datasheet →PIC16C64A-20I/PQ
✅ Drop-In✓ In Stock
$12.2 / Unit
View Datasheet →PIC16C64A-20E/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C64A-04I/PQ
✅ Drop-In✓ In Stock
$6.4 / Unit
View Datasheet →PIC16C64A-10I/PT
✅ Drop-In✓ In Stock
$5.85 / Unit
View Datasheet →PIC16C64A-20/PQ Maximum Ratings & Electrical Characteristics
| Product Family | PIC16C6X |
| Core Architecture | 8-bit RISC PIC |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 3.5 KB |
| RAM Size | 128 bytes |
| Data EEPROM | Not present (program EPROM only) |
| Maximum Clock Frequency | 20 MHz |
| Supply Voltage Range | 2.5 V to 6.0 V |
| I/O Pins | 33 |
| Package | 44-pin MQFP (PQ) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | 0C to +70C (Commercial) |
| Instruction Set Size | 35 instructions |
| Hardware Stack Depth | 8 levels |
| Timers | 3 (Timer0, Timer1, Timer2) |
| Serial Interface | USART/SCI |
| ADC | Not present |
| RoHS Status | Non-compliant (contains lead) |
| Peripherals (Other) | Parallel Slave Port, Capture/Compare/PWM |
PIC16C64A-20/PQ Pin Configuration
| Pin 1 | MCLR/VPP/RA5 — Master Clear (reset) input / Programming voltage / PORTA bit 5 |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input 0 (not used on this part) |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input 1 (not used on this part) |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input 2 (not used on this part) |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / Analog input 3 / Voltage reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/SS/AN4 — PORTA bit 5 / SPI slave select / Analog input 4 |
| Pin 8 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 9 | OSC2/CLKOUT — Oscillator crystal 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 |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK — PORTC bit 6 / USART transmit / clock |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / USART receive / data |
| Pin 18 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 19 | RB1 — PORTB bit 1 |
| Pin 20 | RB2 — PORTB bit 2 |
| Pin 21 | RB3 — PORTB bit 3 |
| Pin 22 | RB4 — PORTB bit 4 |
| Pin 23 | RB5 — PORTB bit 5 |
| Pin 24 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 25 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 26 | VSS — Ground reference |
| Pin 27 | VDD — Positive supply voltage |
| Pin 28 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 29 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 30 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 31 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 32 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 33 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 34 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 35 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 36 | RE0/RD/AN5 — PORTE bit 0 / Read control / Analog 5 |
| Pin 37 | RE1/WR/AN6 — PORTE bit 1 / Write control / Analog 6 |
| Pin 38 | RE2/CS/AN7 — PORTE bit 2 / Chip select / Analog 7 |
| Pin 39 | NC — Not connected (per datasheet) |
| Pin 40 | NC — Not connected (per datasheet) |
| 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
PIC16C64A-20/PQ is suitable for 6 applications: Industrial Control Systems, Appliance Control Panels, Security and Access Control, Automotive Body Electronics, Sensor Measurement Instruments, Legacy Embedded System Maintenance.
Industrial Control Systems
The PIC16C64A-20/PQ fits industrial control applications requiring deterministic 8-bit processing and a wide 2.5 V to 6.0 V supply tolerance for noisy factory environments. Its 20 MHz RISC core executes the 35-instruction set in single instruction cycles (200 ns at full speed), enabling fast PID control loops and sensor polling. The 33 digital I/O lines support direct drive of relays, solenoids, and indicator LEDs without external logic, while the USART interfaces with RS-232/485 transceivers for PLC comms. At 15 uA typical active current, the device suits battery-backed sensor nodes. The MQFP package allows compact PCB layouts in DIN-rail controllers. Recommended companion parts: PIC16C64A-20I/PQ for -40C industrial temperature environments.
Recommended
Appliance Control Panels
The PIC16C64A-20/PQ is well-suited for appliance controllers such as washing machines, dishwashers, and microwave ovens where cost-effective 8-bit processing drives keypads, displays, and motor controls. Its 3.5 KB OTP EPROM holds the entire appliance control algorithm, while 128 bytes RAM suffices for state machine variables and timer accumulators. The 33 I/O lines directly scan 4x4 keypads and drive 7-segment or LCD character displays. Capture/Compare/PWM peripherals control motor speed and triac-fired heater elements. At 1 uA typical current at 3 V / 32 kHz, the device supports standby operation between user inputs. Commercial temperature grade 0C to +70C covers indoor appliance use cases. Recommended companions: PIC16C64A-04I/PQ for cost-sensitive low-speed variants.
Recommended
Security and Access Control
The PIC16C64A-20/PQ serves security alarm panels, access controllers, and keypad entry systems where deterministic real-time response and low standby power are critical. Its 20 MHz core handles keypad debounce, code verification, and tamper monitoring within tight timing windows. The 128-byte RAM stores user codes and event logs, while 3.5 KB OTP EPROM holds the encryption and access control logic. The USART interfaces with RFID readers and serial keypads. At 1 uA at 3 V standby, the device extends battery life in wireless sensor nodes. The 33 I/O directly drive piezo buzzers, status LEDs, and relay outputs for magnetic locks. Recommended companions: PIC16C64A-20/P for prototype development in CERDIP windowed package.
Recommended
Automotive Body Electronics
The PIC16C64A-20/PQ powers legacy automotive body modules such as seat controllers, mirror adjusters, and interior lighting drivers where proven PIC16 firmware is preserved across vehicle platforms. Its 2.5 V to 6.0 V supply tolerance handles 12 V automotive bus transients when paired with external voltage regulation. The 33 I/O directly drive small relays and LED arrays for dashboard indicators, while the USART interfaces with body control modules via LIN or K-Line transceivers. The 20 MHz RISC core runs multiple software state machines concurrently for window lift, sunroof, and lock sequencing. For under-hood applications, the extended -40C to +125C variant PIC16C64A-20E/PQ is required. Recommended companions: PIC16C64A-20E/PQ for engine compartment modules.
Recommended
Sensor Measurement Instruments
The PIC16C64A-20/PQ serves handheld and benchtop measurement instruments including multimeters, thermometers, and data loggers where its 8-bit RISC performance and low-power operation balance accuracy with battery life. The 20 MHz core executes ADC sequencing and averaging algorithms on external 12-bit or 16-bit ADCs connected via parallel PORTC/PORTD. The 128-byte RAM buffers measurement samples between USART transmissions to a host PC or display module. The 33 I/O drive LCD segments, pushbutton inputs, and mode-selector switches. At 1 uA standby current, the device supports months of battery life in intermittent-use instruments. Recommended companions: PIC16C64A-10/PT for lower-power portable variants.
Recommended
Legacy Embedded System Maintenance
The PIC16C64A-20/PQ is the factory-qualified replacement for original PIC16C64A silicon in field-deployed systems where PCB redesign is not feasible. It maintains identical pinout, peripherals, and instruction timing to the original part, allowing firmware binaries to be reused without recompilation in many cases. Customers maintaining industrial PLCs, elevator controls, HVAC thermostats, and textile machinery can substitute PIC16C64A-20/PQ into existing MQFP footprints. The Not Recommended for New Designs (NRND) status is specifically intended to support this maintenance use case while encouraging new designs to migrate to PIC16C65B or modern PIC16F/PIC18 Flash parts. Recommended companions: PIC16C65B for new designs on the same footprint.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C64A-20/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65B-20/PQ | PIC16C64A-20I/PQ | PIC16C64A-20E/PQ | PIC16C64A-04I/PQ |
|---|---|---|---|---|---|
| Package | 44-pin MQFP (PQ) | 44-pin MQFP (PQ) - same | 44-pin MQFP (PQ) - same | 44-pin MQFP (PQ) - same | 44-pin MQFP (PQ) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 3.5 KB OTP EPROM | 7 KB OTP EPROM | 3.5 KB OTP EPROM | 3.5 KB OTP EPROM | 3.5 KB OTP EPROM |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 4 MHz |
| Temperature Range | 0C to +70C (Commercial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) |
| RAM | 128 bytes | 192 bytes | 128 bytes | 128 bytes | 128 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Lifecycle Status | NRND (Not Recommended for New Designs) | NRND (recommended successor) | NRND | NRND | NRND |
Key Differentiators
- Drop-in upgrade with double program memory (vs PIC16C65B-20/PQ)
- Industrial temperature variant for harsh environments (vs PIC16C64A-20I/PQ)
- Extended temperature range for automotive/under-hood (vs PIC16C64A-20E/PQ)
- Lower-cost 4 MHz speed grade for cost-sensitive designs (vs PIC16C64A-04I/PQ)
Design Notes
The PIC16C64A-20/PQ operates from 2.5 V to 6.0 V with typical active current of 15 uA at 5 V / 4 MHz and standby current of 1 uA at 3 V / 32 kHz. Place a 100 nF decoupling capacitor within 1 cm of the VDD pin (pin 27) and a 10 uF bulk capacitor on the supply rail. For battery operation, switching from 20 MHz active mode to 32 kHz sleep mode can reduce average current to under 5 uA, enabling multi-year battery life in sensor nodes. The wide supply tolerance allows direct connection to regulated 5 V rails without additional regulators.
Layout the 44-pin MQFP package with a continuous ground plane beneath the IC to reduce EMI and provide thermal spreading. Crystal traces (OSC1 pin 2, OSC2 pin 3) must be short (< 1 cm) and symmetric to avoid duty-cycle distortion. Place load capacitors (typically 15-33 pF for 20 MHz crystal) directly at the oscillator pins. The MCLR pin (pin 1) requires a 10 kohm pull-up to VDD; do not leave floating. For noisy environments, add a 100 nF capacitor between MCLR and VDD for improved reset noise immunity per Microchip AN588.
OTP EPROM cannot be erased in-circuit: once programmed, the PIC16C64A-20/PQ cannot be reprogrammed. For prototype or firmware-iteration workflows, use the windowed CERDIP variant PIC16C64A-20/P. Configuration bits (oscillator selection, watchdog timer, code protection) must be set correctly during programming or the part will fail to start. The PIC16C64A has NO analog-to-digital converter; applications requiring ADC must add an external ADC. Modern Flash-based alternatives like PIC16F877A-I/PT provide A/D converters and in-circuit reprogramming but require PCB redesign.
The PIC16C64A-20/PQ's parallel slave port (PORTD pins 28-35 plus PORTE pins 36-38) supports high-speed parallel bus communication with external memory or peripherals. When using PSP mode, add 100 ohm series termination resistors on PORTD lines to dampen ringing on long PCB traces. The USART pins (RC6/RC7) require RS-232 transceiver ICs (such as MAX232) for voltage level translation; do not connect directly to RS-232 signals which swing to +/-12 V and will damage the PIC16C64A's CMOS inputs.
Compliance Information
PIC16C64A-20/PQ uses lead-based MQFP package terminations, making it non-RoHS compliant. All variants in the PIC16C64A-20 family share the same MQFP lead content. For RoHS-compliant designs, migrate to PIC16F or PIC18 Flash-based microcontrollers in TQFP packages.
