PIC16C64A-04I/PQ - 4MHz 8-Bit MCU, 3.5KB OTP, MQFP-44 | Microchip
MPN: PIC16C64A-04I/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.52 | $9.52 |
| 10 | $8.85 | $88.50 |
| 100 | $7.9 | $790.00 |
| 500 | $7.05 | $3,525.00 |
| 1,000 | $6.4 | $6,400.00 |
PIC16C64A-04I/PQ Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, data RAM, and peripherals on one die. Within the broader taxonomy, the PIC16C64A belongs to the RISC microcontroller class -> embedded microcontroller -> microcomputer -> integrated circuit. The 8-bit bus width means data is processed 8 bits at a time; the Harvard-style separate program/data buses accelerate instruction fetch, while the RISC instruction set reduces each instruction to a single 200 ns word at 20 MHz.
Key features include 35 single-word instructions, all executing in one instruction cycle except program branches (two cycles), a programmable code protection bit, a watchdog timer with on-chip RC oscillator, and four counter/timer modules. The PIC16C64A integrates a synchronous serial port (SSP) supporting SPI and I2C, a USART for asynchronous serial communication, a 10-bit multi-channel analog comparator subsystem, and a Capture/Compare/PWM (CCP) module.
The device operates from 2.5 V to 6.0 V across the industrial temperature range and supports in-circuit serial programming (ICSP) when used with the appropriate programming hardware. The OTP memory is one-time programmable, making this part best suited for mature production designs where firmware is fixed and high-volume programming is performed at the factory. For in-the-field firmware updates, Flash-based PIC16F equivalents are recommended.
Typical applications include industrial control systems, automotive body and chassis subsystems, consumer appliance controllers, and embedded sensor interfaces. The wide operating voltage range and robust I/O count also make the PIC16C64A a fit for remote sensor data loggers and human-machine interface (HMI) panels where deterministic real-time response is critical.
When designing with this part, note that OTP memory cannot be reprogrammed in-circuit; engineers should plan for a Flash-based PIC16F64A or PIC16F877A migration path during prototyping. A decoupling capacitor of 0.1 uF placed within 5 mm of VDD is recommended, and unused I/O pins should be configured as outputs low to minimize power consumption.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, enabling engineers to make faster BOM decisions for legacy or industrial systems.
Drop-in alternatives for PIC16C64A-04I/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-04I/PQ (same form factor and footprint) — differing in Package, Timers, Program Memory Type, Operating Temperature Range, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C64A-04I/L
✅ Drop-In✓ In Stock
$4.5 / Unit
View Datasheet →PIC16C64AT-04I/PQ
✅ Drop-In✓ In Stock
$7.55 / Unit
View Datasheet →PIC16C64A-04/PQ
✅ Drop-In✓ In Stock
$4.3 / Unit
View Datasheet →PIC16F877A-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C65B-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C64A-04I/PQ Maximum Ratings & Electrical Characteristics
| Core | PIC16C 8-bit RISC |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 3.5 KB (2K x 14 words) |
| RAM | 128 bytes |
| Data EEPROM | 0 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns at 4 MHz |
| I/O Pins | 33 |
| Operating Voltage Range | 2.5 V to 6.0 V |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Package | 44-pin MQFP (10x10 mm) |
| Peripherals | USART, SSP (SPI/I2C), 10-bit ADC comparator, CCP, WDT, POR, BOR |
| Timers | Three 8-bit timer/counters + one 16-bit timer/counter |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Non-compliant (contains lead per legacy MQFP package) |
| Lead-Free | No (legacy MQFP package, lead-bearing) |
| Suggested Replacement | PIC16F877A-I/PQ (Flash equivalent) |
PIC16C64A-04I/PQ Pin Configuration
| Pin 1 | MCLR/VPP — Master clear reset input / programming voltage |
| Pin 2 | RA0/AN0 — Port A bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — Port A bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 — Port A bit 2 / analog input 2 |
| Pin 5 | RA3/AN3/VREF — Port A bit 3 / analog input 3 / voltage reference |
| Pin 6 | RA4/T0CKI — Port A bit 4 / Timer 0 clock input |
| Pin 7 | RA5/AN4/SS — Port A bit 5 / analog input 4 / SSP slave select |
| Pin 8 | RE0/RD/AN5 — Port E bit 0 / parallel slave read / analog input 5 |
| Pin 9 | RE1/WR/AN6 — Port E bit 1 / parallel slave write / analog input 6 |
| Pin 10 | RE2/CS/AN7 — Port E bit 2 / parallel slave chip select / analog input 7 |
| Pin 11 | VDD — Positive power supply |
| 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 — Port C bit 0 / Timer 1 oscillator output / clock input |
| Pin 16 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer 1 oscillator input / CCP2 |
| Pin 17 | RC2/CCP1 — Port C bit 2 / Capture-Compare-PWM 1 |
| Pin 18 | RC3/SCK/SCL — Port C bit 3 / SSP SPI clock / I2C clock |
| Pin 19 | RD0 — Port D bit 0 |
| Pin 20 | RD1 — Port D bit 1 |
| Pin 21 | RD2 — Port D bit 2 |
| Pin 22 | RD3 — Port D bit 3 |
| Pin 23 | RC4/SDI/SDA — Port C bit 4 / SSP SPI data in / I2C data |
| Pin 24 | RC5/SDO — Port C bit 5 / SSP SPI data out |
| Pin 25 | RC6/TX/CK — Port C bit 6 / USART transmit / USART clock |
| Pin 26 | RC7/RX/DT — Port C bit 7 / USART receive / USART data |
| Pin 27 | RD4 — Port D bit 4 |
| Pin 28 | RD5 — Port D bit 5 |
| Pin 29 | RD6 — Port D bit 6 |
| Pin 30 | RD7 — Port D bit 7 |
| Pin 31 | VSS — Ground |
| Pin 32 | VDD — Positive power supply |
| Pin 33 | RB0/INT — Port B bit 0 / external interrupt |
| Pin 34 | RB1 — Port B bit 1 |
| Pin 35 | RB2 — Port B bit 2 |
| Pin 36 | RB3 — Port B bit 3 |
| Pin 37 | RB4 — Port B bit 4 |
| Pin 38 | RB5 — Port B bit 5 |
| Pin 39 | RB6/PGC — Port B bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — Port B bit 7 / ICSP data |
| Pin 41 | VSS — Ground |
| Pin 42 | VDD — Positive power supply |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C64A-04I/PQ is suitable for 6 applications: Industrial Control Systems, Automotive Body Electronics, Consumer Appliance Controllers, Remote Sensor Data Loggers, Human-Machine Interface (HMI) Panels, Security and Access Control.
Industrial Control Systems
The PIC16C64A-04I/PQ fits industrial control applications because of its industrial -40 C to +85 C temperature grade, wide 2.5-6.0 V operating range, and 33 digital I/O lines that can directly drive relays, solenoids, and sensor arrays. The PIC16C6X mid-range RISC core delivers deterministic 200 ns instruction cycle times at 4 MHz, essential for real-time PID loops and machine state machines. Its integrated USART enables reliable RS-232/RS-485 communication with PLC masters, while the Capture/Compare/PWM module generates precise timing signals for motor control. OTP memory is acceptable here because industrial firmware is factory-programmed and rarely updated. Estimated: at 4 MHz clock the CPU can service a 1 kHz control loop with 99.98% idle margin for housekeeping tasks.
Recommended
Automotive Body Electronics
The PIC16C64A-04I/PQ is suitable for automotive body and chassis subsystems (lighting controllers, seat controllers, instrument clusters) due to its industrial temperature rating and rugged CMOS design. Its 33 I/O pins directly switch lamps and motors via MOSFET drivers, while the USART interfaces with CAN or LIN transceivers for in-vehicle networking. The PIC16C6X core's Harvard architecture and single-cycle instructions deliver the deterministic interrupt response needed for sensor fusion and anti-pinch window control. Although AEC-Q100 is not formally qualified, the industrial temperature range is acceptable for cabin-mounted modules. For under-hood applications above +85 C, migrate to AEC-Q100-qualified PIC18 or dsPIC equivalents.
Recommended
Consumer Appliance Controllers
The PIC16C64A-04I/PQ powers washing-machine, dishwasher, and microwave-oven controllers where 8-bit processing, low cost, and OTP-secured firmware are advantageous. The wide 2.5-6.0 V supply range tolerates unregulated 5 V or 3.3 V rails from rectified mains adapters. With 33 I/O pins, the MCU reads keypads, drives seven-segment or LCD displays, and switches triac-driven loads without external glue logic. OTP memory locks firmware against unauthorized modification - an IP-protection benefit for white-goods OEMs. Brown-out reset and watchdog timer improve field reliability against brownouts and software lockups. Typical firmware occupies ~2.5 KB of the 3.5 KB program memory, leaving headroom for feature expansion.
Recommended
Remote Sensor Data Loggers
The PIC16C64A-04I/PQ suits remote sensor data loggers that need low power, deterministic timing, and serial communication. Its 4 MHz clock and 200 ns instruction cycle are sufficient for 10 Hz multi-channel temperature, pressure, or humidity sampling with on-the-fly averaging. The 128-byte RAM stores rolling buffers before serial transmission via USART or SSP. Brown-out reset and watchdog timer improve field reliability in unattended solar-powered installations. The 2.5 V minimum supply allows operation from two AA cells with a boost converter, extending battery life. OTP memory prevents accidental field corruption, though designers should plan for a Flash-based migration path during pilot phases.
Recommended
Human-Machine Interface (HMI) Panels
The PIC16C64A-04I/PQ drives simple HMI panels combining keypads, LED indicators, character LCDs, and rotary encoders. Its 33 I/O pins multiplex 4x4 keypads, 7-segment displays, and up to 16 status LEDs without external latches. The CCP module generates PWM tones for audible feedback, while the USART communicates with a higher-level PLC or HMI controller. With 3.5 KB OTP, the firmware handles debounce, menu navigation, and serial protocols. The 200 ns instruction cycle enables crisp encoder tracking at 1 kHz rotation rates. For graphic TFT panels, migrate to PIC18F or PIC32 with integrated LCD controllers.
Recommended
Security and Access Control
The PIC16C64A-04I/PQ is appropriate for security peripherals (keypad entry controllers, RFID readers, alarm panels) because OTP memory prevents firmware tampering and reverse-engineering of authentication algorithms. The 33 I/O lines drive keypads, magnetic-stripe readers, RFID antenna switches, and 12 V alarm sirens via MOSFET drivers. The on-chip USART interfaces with central alarm panels, while the SSP supports SPI RFID modules. Brown-out detection and watchdog timer protect against supply glitches and software lockups that could disable the alarm. Estimated: at 4 MHz the CPU scans a 4x4 keypad in 4 ms with 99% idle margin for cryptographic check routines.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C64A-04I/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C64A-04I/L | PIC16C64AT-04I/PQ | PIC16F877A-I/PQ | PIC16C65B-I/PQ |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | MQFP-44 (PQ) | PLCC-44 (L) - different footprint | MQFP-44 (PQ) - same | MQFP-44 (PQ) - same | MQFP-44 (PQ) - same |
| Program Memory | 3.5 KB OTP | 3.5 KB OTP (same) | 3.5 KB OTP (same) | 14 KB Flash | 7 KB OTP |
| RAM | 128 bytes | 128 bytes | 128 bytes | 368 bytes | 192 bytes |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Memory Type | OTP | OTP | OTP | Flash | OTP |
| Temperature Grade | Industrial (-40 to +85 C) | Industrial | Industrial | Industrial | Industrial |
| Operating Voltage | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.5 V to 6.0 V | 2.0 V to 5.5 V | 2.5 V to 6.0 V |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Active | Obsolete |
Key Differentiators
- OTP memory prevents firmware tampering (vs PIC16F877A-I/PQ)
- Wider operating voltage range than Flash successor (vs PIC16F877A-I/PQ)
- Industrial temperature grade available in legacy form (vs PIC16C64A-04/PQ)
- Smaller program memory for cost-optimized designs (vs PIC16C65B-I/PQ)
Design Notes
Place a 0.1 uF decoupling capacitor within 5 mm of each VDD pin (pins 11, 32, 42) and a single bulk capacitor (10 uF tantalum or aluminum) near the package. The PIC16C64A has three VDD/VSS pairs distributed around the MQFP-44 to minimize supply loop inductance - all three must be decoupled, not just one. Estimated: at 4 MHz clock and 5 V supply, the MCU draws approximately 5 mA active and 1 uA in sleep mode, so decoupling should target a 50 mA transient load capability.
The 44-pin MQFP package has 0.8 mm lead pitch and requires careful PCB layout to avoid solder bridges. Use a 0.4 mm wide solder paste stencil aperture (50% pad width) and a reflow profile with peak temperature of 235 C to 245 C for lead-bearing SAC305 or Sn63Pb37 paste. For hand prototyping, MQFP-44 to DIP-44 adapters are widely available but introduce ~5 mm of additional board height. Consider the PLCC-44 (L) variant for socketed development and the MQFP-44 (PQ) for production.
OTP memory cannot be erased or rewritten - any code bug is permanent. Always validate firmware on a Flash-based PIC16F877A-I/PQ emulator before committing to PIC16C64A production programming. The PIC16C64A also lacks a debug peripheral, so in-circuit debugging requires a third-party ICD or an MPLAB-ICE replacement. Brown-out reset must be enabled in the configuration word; otherwise voltage dips during motor switching can corrupt RAM and cause undefined behavior. The MCLR pin is bidirectional - tie to VDD through a 10 kohm resistor and to ground through a 100 nF capacitor for clean reset.
Route the OSC1/OSC2 traces as short as possible and keep them away from high-current switching nodes (relay coils, motor drivers) to prevent clock jitter. The USART and SSP pins should be routed with characteristic impedance of 50 ohm if the trace length exceeds 50 mm, or terminated with a series resistor if reflections are observed. The PSP (parallel slave port) pins RE0/RE1/RE2 and RD0-RD7 are high-speed digital lines; keep them grouped and away from analog AVdd/VREF traces. Estimated: at 4 MHz, signal rise time is approximately 25 ns, so trace length matching should hold to within 10 mm between parallel data lines.
Compliance Information
MQFP-44 (PQ) package contains lead-bearing solder terminations and is not RoHS compliant. PIC16C64A is not AEC-Q100 qualified; PIC16F877A-I/PQ is recommended for automotive applications. REACH compliance verified per Microchip product declaration.
