PIC16C64AT-20I/PQ - 8-Bit 20MHz OTP MCU, 3.5KB | Microchip
MPN: PIC16C64AT-20I/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.5 | $9.50 |
| 10 | $8.55 | $85.50 |
| 100 | $7.6 | $760.00 |
| 500 | $6.65 | $3,325.00 |
| 1,000 | $5.7 | $5,700.00 |
PIC16C64AT-20I/PQ Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripheral interfaces onto one die. The PIC16CXX family is built on a fully-static CMOS architecture with a Harvard memory layout, meaning the program and data buses are physically separate. The C family is the classic OTP lineage that preceded the Flash-based F series; OTP parts are programmed once with a device programmer and cannot be electrically erased, which suits cost-sensitive production runs. Within the power-management IC hierarchy, this part sits at the controller/signal-processing tier alongside 8-bit microcontrollers from 8051, AVR, and HC11 families.
Key features include a 14-bit instruction set optimized for compact code, a hardware USART for asynchronous serial links, an 8-bit parallel slave port for bus expansion, and a programmable watchdog timer with its own on-chip RC oscillator for fail-safe operation. The 33 I/O pins are grouped into five ports (PORTA–PORTE), each capable of sourcing or sinking sufficient current to drive LEDs and small relays directly. Brown-out-reset circuitry holds the part in reset when VDD dips below a programmable threshold, preventing code corruption from indeterminate supply rails.
Architecture-wise, the PIC16C64A integrates an 8-level hardware stack for subroutine nesting, a 14-bit program counter that addresses the full 8K x 14 OTP space, and an interrupt controller handling up to 12 sources including external edge-triggered events. The core executes most instructions in a single 200 ns instruction cycle at 20 MHz, delivering roughly 5 MIPS of throughput. A 5-bit port-RA multiplexed analog comparator and two analog comparators further extend the analog front-end without external ICs.
Typical applications include industrial automation controllers, consumer-electronics user-interface boards, automotive body and convenience modules (with PIC16F variants recommended for new designs), appliance control panels, and remote sensor signal-conditioning front-ends. Designers continue to specify this OTP part where mature firmware is locked and per-unit cost is critical. A practical design consideration is the OTP memory: firmware must be fully validated, since field firmware updates are impossible. For new designs, consider the pin-compatible PIC16F877A (Flash) variant to gain in-circuit reprogrammability without changing the PCB layout.
Drop-in alternatives for PIC16C64AT-20I/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-20I/PQ (same form factor and footprint) — differing in Package, RoHS Status, Timers, I/O Pins, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C64A-20I/PQ
✅ Drop-In✓ In Stock
$12.2 / Unit
View Datasheet →PIC16C64AT-20/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C64AT-20E/PQ
✅ Drop-In✓ In Stock
$7.2 / Unit
View Datasheet →PIC16C64A-20/PQ
✅ Drop-In✓ In Stock
$5.2 / Unit
View Datasheet →PIC16C64AT-20I/PQ Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Family | PIC16CXX |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 3.5 KB (2K x 14) |
| RAM Size | 128 x 8 bytes |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns at 20 MHz |
| Supply Voltage (VDD) | 4 V to 6 V |
| I/O Pins | 33 programmable |
| Serial Interfaces | I2C, SPI, USART |
| Timers | Timer0, Timer1, Timer2 + WDT |
| Package | 44-pin MQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 °C to +85 °C (Industrial) |
| Temperature Grade | Industrial (I) |
| RoHS Status | ROHS3 Compliant |
PIC16C64AT-20I/PQ Pin Configuration
| Pin 1 | OSC1/CLKIN — Oscillator crystal input or external clock input |
| Pin 2 | OSC2/CLKOUT — Oscillator crystal output; CLKOUT when in RC mode |
| Pin 3 | MCLR/VPP — Master Clear reset / programming voltage input |
| Pin 4 | RA0 — PORTA bit 0 (analog comparator input) |
| Pin 5 | RA1 — PORTA bit 1 (analog comparator input) |
| Pin 6 | RA2 — PORTA bit 2 (analog comparator input) |
| Pin 7 | RA3 — PORTA bit 3 (analog comparator input) |
| Pin 8 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 9 | RA5/SS — PORTA bit 5 / SPI slave select |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply (4-6 V) |
| Pin 12 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 13 | RB1 — PORTB bit 1 |
| Pin 14 | RB2 — PORTB bit 2 |
| Pin 15 | RB3 — PORTB bit 3 |
| Pin 16 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 17 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 18 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 19 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 20 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator/counter |
| Pin 21 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator input |
| Pin 22 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 23 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 24 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 25 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 26 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 27 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 28 | VSS — Ground reference |
| Pin 29 | VDD — Positive supply (4-6 V) |
| Pin 30 | RD0 — PORTD bit 0 |
| Pin 31 | RD1 — PORTD bit 1 |
| Pin 32 | RD2 — PORTD bit 2 |
| Pin 33 | RD3 — PORTD bit 3 |
| Pin 34 | RD4 — PORTD bit 4 |
| Pin 35 | RD5 — PORTD bit 5 |
| Pin 36 | RD6 — PORTD bit 6 |
| Pin 37 | RD7 — PORTD bit 7 |
| Pin 38 | VSS — Ground reference |
| Pin 39 | VDD — Positive supply (4-6 V) |
| Pin 40 | RE0/RD — PORTE bit 0 / parallel slave port read |
| Pin 41 | RE1/WR — PORTE bit 1 / parallel slave port write |
| Pin 42 | RE2/CS — PORTE bit 2 / parallel slave port chip select |
| Pin 43 | VSS — Ground reference |
| Pin 44 | VDD — Positive supply (4-6 V) |
Typical Applications
PIC16C64AT-20I/PQ is suitable for 7 applications: Industrial Automation Controller, Consumer Electronics User Interface, Appliance Control Panel, Remote Sensor Signal Conditioning, Automotive Body and Convenience Modules, Security and Alarm System Controller, Educational and Hobbyist Development.
Industrial Automation Controller
The PIC16C64AT-20I/PQ's 20 MHz core, 33 I/O pins, and 3.5 KB OTP program memory make it well suited for industrial automation controllers driving relays, optocouplers, and small signal-conditioning front-ends. Its 4–6 V supply range tolerates the noisy 5 V rails typical of factory-floor environments, and the integrated brown-out reset holds the part safely during supply dips. The 128 bytes of RAM are sufficient for typical PLC-style ladder logic replacement, while the hardware USART handles RS-485 communication with industrial sensors. The 44-MQFP package suits compact control boards mounted in DIN-rail enclosures, and the on-chip MSSP enables I2C/SPI communication with sensor arrays and EEPROM storage.
Recommended
Consumer Electronics User Interface
The PIC16C64AT-20I/PQ drives consumer-electronics front-panel user interfaces with its 33 I/O pins capable of sourcing/sinking 25 mA per pin to drive LEDs and small relays directly. The 20 MHz clock delivers smooth multiplexing of 8-digit 7-segment displays, while the MSSP peripherals handle I2C communication with key-scan expanders and SPI control of LCD modules. The OTP memory suits mature, locked-firmware products where per-unit cost dominates, and the 44-MQFP package fits beneath the display stack. The integrated analog comparators enable touch-button sensing without external ICs, reducing BOM cost for high-volume consumer goods.
Recommended
Appliance Control Panel
The PIC16C64AT-20I/PQ is a strong fit for appliance control panels — washing machines, microwave ovens, and dishwasher user interfaces — where the locked-firmware OTP memory and low per-unit cost are key advantages. Its 5 MIPS throughput handles simultaneous button scanning, LED/PWM indicator driving, and sensor polling with headroom. The hardware USART connects to motor-control boards via a simple UART protocol, while the integrated timers generate the precise PWM signals needed for variable-speed drives. The 44-MQFP footprint is compatible with the panel's compact PCB, and the industrial -40 °C to +85 °C rating covers kitchen and laundry environments.
Recommended
Remote Sensor Signal Conditioning
The PIC16C64AT-20I/PQ's on-chip analog comparators and MSSP peripherals enable it to condition and transmit data from remote sensor front-ends over SPI or I2C buses. The 20 MHz clock allows fast sampling of pulsed sensor outputs (e.g., ultrasonic or IR receivers), while the 33 I/O pins route multiplexed analog inputs to the comparators without external switching. Brown-out-reset circuitry prevents corrupted sensor data during supply transients on long cable runs. The OTP memory locks calibrated sensor algorithms permanently, preventing field tampering in metrology applications. Industrial temperature rating supports outdoor and unconditioned enclosures.
Recommended
Automotive Body and Convenience Modules
Although the standard 'I' (industrial) grade of PIC16C64AT-20I/PQ covers body electronics only, the extended 'E' (-40 °C to +125 °C) variant — PIC16C64A-20E/PQ — qualifies for automotive body modules such as window lifters, mirror controllers, and seat-position memory. The 44-MQFP footprint with 33 I/O pins handles H-bridge drivers and switch-matrix scanning, and the USART links to the vehicle CAN/LIN gateway via external transceivers. The OTP memory locks validated firmware against unauthorized modification. Designers targeting new automotive designs should select AEC-Q100-qualified Flash parts, but legacy designs continue to deploy this part successfully.
Recommended
Security and Alarm System Controller
The PIC16C64AT-20I/PQ is well suited as the main controller in wired security and alarm panels, where its 33 I/O pins accommodate multiple zone inputs, siren outputs, keypad scanning, and dialer interfaces. The MSSP enables I2C communication with keypad/display peripherals while the USART drives a modem or wireless module. Brown-out reset ensures the panel reboots cleanly after power outages, and the watchdog timer recovers from firmware lockups. The OTP memory prevents field tampering with validated alarm logic, and the industrial -40 °C to +85 °C range tolerates unheated garages and outdoor equipment closets.
Recommended
Educational and Hobbyist Development
The PIC16C64AT-20I/PQ remains a popular part in university embedded-systems curricula and hobbyist projects because of its mature toolchain support, abundant reference code, and forgiving 5 V supply range. The 44-MQFP package is breadboard-friendly when paired with a TQFP-to-DIP breakout adapter, exposing 33 I/O pins for student projects ranging from line-following robots to home automation. The MSSP, USART, and timer peripherals cover the full PIC16 peripheral set taught in introductory courses, and the OTP memory mirrors industry practice of locked-firmware production. Legacy PICkit and ICD programmers support this part for educational labs.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C64AT-20I/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C64A-20I/PQ | PIC16C64AT-20/PQ | PIC16C64AT-20E/PQ | PIC16C64A-20/PQ |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-MQFP (10x10) | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-MQFP (10x10) - 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) |
| Maximum Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Operating Temperature | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C (Industrial) | 0 °C to +70 °C (Commercial) | -40 °C to +125 °C (Extended) | 0 °C to +70 °C (Commercial) |
| RAM Size | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND |
Key Differentiators
- Industrial temperature grade (-40 °C to +85 °C) (vs PIC16C64AT-20/PQ)
- Industrial vs extended temperature range (vs PIC16C64AT-20E/PQ)
- Mature ecosystem and abundant documentation (vs ATmega329V-8MI)
Design Notes
The PIC16C64AT-20I/PQ operates from 4 V to 6 V VDD; design the supply rail with a low-ESR 100 nF ceramic decoupling capacitor placed within 5 mm of each VDD/VSS pin pair. According to the Microchip datasheet, the device draws approximately 5 mA at 5 V/20 MHz; for low-power applications enable the SLEEP instruction and wake via Watchdog Timer or external interrupt. Brown-out-reset should be enabled (BOREN configuration bit) to guarantee clean reset during power dips.
The 44-MQFP package uses 0.8 mm pitch gull-wing leads — keep-out zone for traces should be designed for 0.5 mm clearance beneath the package body and 0.3 mm between pads. Place a ground pour under the IC body to reduce EMI coupling into analog comparator inputs on PORTA. The MCLR/VPP pin requires a 10 kΩ pull-up to VDD; do not leave it floating. ICSP clock (PGC, pin 18) and data (PGD, pin 19) should be brought out to a programming header for in-circuit programming.
Do not assume OTP memory can be erased or rewritten — the PIC16C64A is One-Time-Programmable and any programming error (e.g., bad configuration bits or code bug) renders the part unusable. Validate firmware on PIC16F or PIC18 equivalents in development, then port to PIC16C64A only after lock-down. Watchdog timer must be enabled (configuration WDTE bit) for fail-safe recovery from firmware lockups. The USART pins (RC6/RC7) are shared with PORTB; do not toggle these pins without disabling the USART peripheral.
Route the 20 MHz crystal traces (OSC1, OSC2) short and symmetric, with a ground guard trace on both sides to prevent coupling into PORTA analog comparator inputs. Place the crystal within 5 mm of the IC pins, and avoid routing signal traces under the crystal traces. For EMC-sensitive designs, add a ferrite bead on VDD and a 1 nF X7R bypass on each PORTA analog input to filter high-frequency noise from switched-mode supplies nearby.
Compliance Information
ROHS3 compliant per distributor listings. Not AEC-Q100 qualified — for automotive applications choose the PIC16C64A-20E/PQ extended-temperature variant or a Flash-based PIC18F/Kinetis equivalent.
