PIC16C64AT-20/PQ - 8-Bit 20MHz OTP MCU 3.5KB | Microchip
MPN: PIC16C64AT-20/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.95 | $6.95 |
| 10 | $6.2 | $62.00 |
| 100 | $5.5 | $550.00 |
| 500 | $4.95 | $2,475.00 |
| 1,000 | $4.45 | $4,450.00 |
PIC16C64AT-20/PQ Overview
An 8-bit microcontroller (MCU) is a single-chip processor that integrates CPU core, program memory, working RAM, and peripheral interfaces on one die. PIC microcontrollers use a Harvard RISC architecture that decouples program and data buses, executes one instruction per clock cycle (except branches), and supports only 35 single-word instructions. Within the broader taxonomy, the PIC16C64A sits between 8-bit MCUs and the wider PIC16 mid-range family, which itself belongs to the microcontroller hierarchy of the semiconductor category.
Key features of the PIC16C64AT-20/PQ include a 200 ns instruction cycle at 20 MHz, two 8-bit and one 16-bit timer/counter, a synchronous serial port (SSP) supporting SPI and I2C, a parallel slave port, and a USART. The 33 I/O pins can drive source/sink currents up to 25 mA per pin, simplifying direct interface to relays, LEDs, and bipolar transistors. The OTP program memory allows low-cost prototyping with stable firmware retention, while the 14-bit instruction word supports immediate and literal operations.
Architecturally, the PIC16C64A uses a 14-bit program word and an 8-bit data path, with an 8-level hardware stack for subroutine calls and a programmable watchdog timer for safe recovery from code lockups. The MQFP-44 package offers ample I/O for motor, display, and instrumentation applications, while commercial temperature grade (0 °C to +70 °C) targets consumer and industrial environments. The 'T' suffix denotes tape-and-reel packaging for high-volume assembly, and the 'PQ' package code designates the plastic MQFP form factor.
Typical applications include motor control, industrial automation, HVAC controllers, security and access systems, and instrumentation front-ends. The deterministic instruction timing makes the part effective for closed-loop control where predictable interrupt latency is required.
When designing with this device, plan for an external oscillator (crystal or resonator) since no internal RC is provided on the PIC16C64A, and ensure the brown-out reset configuration matches the application supply profile. The OTP memory requires pre-programming before PCB assembly for production units.
This page synthesizes current distributor pricing, parametric drop-in alternatives from the same PIC16C family, and practical design notes not found in the standalone datasheet.
Drop-in alternatives for PIC16C64AT-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 PIC16C64AT-20/PQ (same form factor and footprint) — differing in Package, Timers, Mounting Type, ADC, Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C64A-20/PQ
✅ Drop-In✓ In Stock
$5.2 / 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)
PIC16C64AT-20E/PQ
✅ Drop-In✓ In Stock
$7.2 / Unit
View Datasheet →PIC16F877A-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C64AT-20/PQ Maximum Ratings & Electrical Characteristics
| Core | PIC16C 8-bit RISC |
| Instruction Set Architecture | 14-bit instruction word, 35 single-word instructions |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 3.5 KB (2K x 14) |
| RAM Size | 128 x 8 bytes |
| Number of I/O Pins | 33 |
| Supply Voltage | 5 V nominal (PIC16C6X family spec) |
| Timers | 2 x 8-bit + 1 x 16-bit (TMR0/TMR1/TMR2) |
| Communication Interfaces | SSP (SPI / I2C), USART |
| Parallel Slave Port | Yes (8-bit) |
| Watchdog Timer | Yes (programmable) |
| Brown-out Reset | Yes |
| Operating Temperature | 0C to +70C (commercial grade) |
| Package | 44-MQFP (10x10 mm), gull-wing leads |
| Mounting Type | Surface Mount (Tape & Reel) |
| Terminal Form | GULL WING |
PIC16C64AT-20/PQ Pin Configuration
| Pin 1 | MCLR/VPP — Master clear (reset) input / programming voltage |
| Pin 2 | OSC1/CLKIN — Oscillator crystal input or external clock input |
| Pin 3 | OSC2/CLKOUT — Oscillator crystal output or clock output (FOSC/4) |
| Pin 4 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 5 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 6 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Pin 7 | RA3/AN3/VREF — PORTA bit 3 / analog input 3 / VREF |
| Pin 8 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 9 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SSP slave select |
| Pin 10 | RE0/RD/AN5 — PORTE bit 0 / parallel port read control / analog input 5 |
| Pin 11 | RE1/WR/AN6 — PORTE bit 1 / parallel port write control / analog input 6 |
| Pin 12 | RE2/CS/AN7 — PORTE bit 2 / parallel port chip select / analog input 7 |
| Pin 13 | VDD — Positive supply (5V) |
| Pin 14 | VSS — Ground reference |
| Pin 15 | OSC1 — Crystal oscillator input (timer1 alternate) / RC oscillator |
| Pin 16 | OSC2 — Crystal oscillator output |
| Pin 17 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 18 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 19 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM1 |
| Pin 20 | RC3/SCK/SCL — PORTC bit 3 / SSP clock (SPI/I2C) |
| Pin 21 | RC4/SDI/SDA — PORTC bit 4 / SSP data in / I2C data |
| Pin 22 | RC5/SDO — PORTC bit 5 / SSP data out |
| Pin 23 | RC6/TX/CK — PORTC bit 6 / USART async transmit / sync clock |
| Pin 24 | RC7/RX/DT — PORTC bit 7 / USART async receive / sync data |
| Pin 25 | VSS — Ground reference |
| Pin 26 | RB0/INT — PORTB bit 0 / external interrupt input |
| Pin 27 | RB1 — PORTB bit 1 |
| Pin 28 | RB2 — PORTB bit 2 |
| Pin 29 | RB3 — PORTB bit 3 |
| Pin 30 | RB4 — PORTB bit 4 |
| Pin 31 | RB5 — PORTB bit 5 |
| Pin 32 | RB6/PGC — PORTB bit 6 / ICSP clock (serial programming) |
| Pin 33 | RB7/PGD — PORTB bit 7 / ICSP data (serial programming) |
| Pin 34 | VDD — Positive supply (5V) |
| Pin 35 | VSS — Ground reference |
| Pin 36 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 37 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 38 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 39 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 40 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 41 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 42 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 43 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 44 | VSS — Ground reference |
Typical Applications
PIC16C64AT-20/PQ is suitable for 7 applications: Industrial Motor Control, HVAC Climate Controllers, Security and Access Systems, Instrumentation Front-Ends, Consumer Appliance Controllers, Automotive Body Electronics (Legacy), Educational and Prototyping Boards.
Industrial Motor Control
The PIC16C64AT-20/PQ fits industrial motor-control boards because its 20 MHz RISC core delivers deterministic 200 ns instruction timing, essential for PWM-driven closed-loop control of DC and stepper motors. The 33 I/O pins let engineers drive phase outputs, sense Hall-effect feedback, and read encoder signals without external multiplexers. Per the PIC16C6X datasheet, the 25 mA source/sink per pin directly powers optocouplers and small relay coils, eliminating driver stages. The 16-bit TMR1 timer provides precise PWM periods for variable-speed drives. Compared with flash-based PIC16F equivalents, the OTP architecture suits cost-optimized, high-volume motor modules where firmware is finalized and stability outweighs in-field reprogrammability.
Recommended
HVAC Climate Controllers
The PIC16C64AT-20/PQ suits HVAC climate-control systems where predictable interrupt latency, low power, and 33 I/O simplify interfacing to temperature sensors, triac-driven fan outputs, and keypad/display panels. The PIC16C6X architecture's deterministic 200 ns instruction cycle keeps temperature sampling and PID calculations running at fixed intervals, critical for stable indoor climate regulation. Brown-out reset protects the controller from compressor startup transients. The 3.5 KB OTP program memory stores control algorithms for multi-zone systems, and the parallel slave port allows connection to a main display controller. Engineers select this part for high-volume residential HVAC where the OTP cost advantage outweighs flash reprogrammability.
Recommended
Security and Access Systems
The PIC16C64AT-20/PQ is a strong fit for security and access-control panels, where its 33 I/O pins accept keypad matrix inputs, door-sensor contacts, and alarm outputs without external glue logic. The PIC16C6X core's 35-instruction RISC architecture simplifies code review for safety-critical firmware, and the hardware watchdog timer ensures recovery from code lockup that could disable an alarm. The 3.5 KB OTP memory is ideal for sealed, tamper-resistant products where firmware is finalized at production. USART and SSP peripherals enable integration with card readers and central monitoring panels. Commercial temperature grade suits indoor installations, and the MQFP-44 footprint provides reliable hand-solderable rework for serviceability.
Recommended
Instrumentation Front-Ends
The PIC16C64AT-20/PQ's deterministic 200 ns instruction cycle makes it well suited for instrumentation front-ends where sample timing must remain stable across environmental changes. The 33 I/O pins interface to LCD modules, rotary encoders, and analog multiplexer select lines, while the USART delivers measurement data to a host PC. Per the PIC16C6X datasheet, the SSP peripheral supports SPI interfacing to modern 24-bit sigma-delta ADCs used in precision scales and multimeters. The 3.5 KB OTP memory holds calibration tables and linearization routines, and brown-out reset protects measurement integrity during supply dips. Engineers value this part for portable instruments that require predictable timing without flash reprogramming complexity.
Recommended
Consumer Appliance Controllers
The PIC16C64AT-20/PQ targets cost-sensitive consumer appliances such as washing machines, microwave ovens, and dishwasher control boards. Its 33 I/O pins drive seven-segment displays, touch keypads, and triac-controlled heaters, while the 3.5 KB OTP memory holds the appliance state machine and safety logic. The PIC16C6X architecture's single-cycle 200 ns execution keeps button-debounce and timing routines fast and predictable, improving user responsiveness. Commercial temperature grade covers kitchen environments, and the MQFP-44 package with gull-wing leads survives standard IR-reflow profiles. Compared with flash parts, the OTP variant reduces BOM cost for high-volume SKUs shipping millions of units annually.
Recommended
Automotive Body Electronics (Legacy)
The PIC16C64AT-20/PQ historically served automotive body-electronics modules such as seat controllers, mirror adjusters, and lighting drivers where cost and deterministic timing outweighed flash reprogrammability. With 33 I/O and 25 mA pin drive, it interfaces directly to small relays, LED arrays, and H-bridge motor drivers. Although the part's commercial 0C to +70C temperature range limits under-hood deployment, the extended-grade variant PIC16C64AT-20E/PQ supports cabin environments down to -40C. The PIC16C6X watchdog and brown-out reset improve robustness against automotive electrical noise. Modern designs typically migrate to PIC16F877A-I/PQ flash parts, but the OTP PIC16C64A remains in long-lifecycle aftermarket modules.
Recommended
Educational and Prototyping Boards
The PIC16C64AT-20/PQ is widely adopted in university microcontroller courses and hobbyist projects because its 35-instruction RISC architecture makes assembly programming approachable for beginners. The 33 I/O pins and dual timer modules expose enough peripherals for capstone projects ranging from line-following robots to digital voltmeters. The 3.5 KB OTP memory holds moderate assembly programs and forces students to plan code size carefully, an enduring pedagogical lesson. The MQFP-44 package with standard 0.8 mm lead pitch is hand-solderable with practice. Instructors prefer this part for teaching timing diagrams and interrupt-driven design, and the PIC16C6X datasheet provides extensive example code. Flash-based PIC16F equivalents are recommended for student projects requiring reprogramming iterations.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C64AT-20/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C64A-20/PQ | PIC16C64A-20I/PQ | PIC16C64A-20E/PQ | PIC16C64AT-20E/PQ | PIC16F877A-I/PQ |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-MQFP (10x10) PQ | 44-MQFP (10x10) PQ - same | 44-MQFP (10x10) PQ - same | 44-MQFP (10x10) PQ - same | 44-MQFP (10x10) PQ - same | 44-MQFP (10x10) PQ - same |
| Program Memory | 3.5 KB OTP (2K x 14) | 3.5 KB OTP (2K x 14) | 3.5 KB OTP (2K x 14) | 3.5 KB OTP (2K x 14) | 3.5 KB OTP (2K x 14) | 14 KB Flash |
| Maximum Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Number of I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| Operating Temperature | 0C to +70C (commercial) | 0C to +70C | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +125C (extended) | -40C to +85C (industrial) |
| Memory Technology | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | Flash |
| Lifecycle Status | Obsolete (legacy OTP) | Obsolete | Obsolete | Obsolete | Obsolete | Active (recommended migration) |
Key Differentiators
- Flash reprogrammability eliminates OTP programming tooling (vs PIC16F877A-I/PQ)
- Industrial temperature grade for harsher environments (vs PIC16C64A-20/PQ)
- Extended temperature for automotive cabin and industrial modules (vs PIC16C64A-20/PQ)
Design Notes
Estimated: at 20 MHz with all 33 I/O toggling, the PIC16C64AT-20/PQ draws approximately 15-25 mA from VDD; add 0.1 uF ceramic decoupling close to each VDD pin (pins 13 and 34) and a bulk 10 uF tantalum on the supply rail. The PIC16C6X datasheet recommends placing decoupling within 5 mm of each VDD/VSS pair to suppress switching noise.
Route the crystal traces between OSC1 (pin 2) and OSC2 (pin 3) as short as possible with a ground guard ring to avoid coupling digital switching noise into the oscillator. Per Microchip oscillator design notes, load capacitors should be sized per the crystal ESR and placed directly at the OSC pins to maintain 20 MHz stability across temperature.
Do not assume in-system reprogrammability - the PIC16C64AT-20/PQ uses OTP EPROM that can be programmed once before solder and cannot be erased afterward. Plan firmware verification using windowed PIC16C64A-04/JW samples during development, then commit the final code to OTP for production. Brown-out reset must be enabled in the configuration word to protect against supply dips during OTP programming.
Compliance Information
Compliance data not present in verified web data; PIC16C6X family pre-dates many current compliance standards. Confirm with Microchip for production deployment.
