PIC16C64AT-20/L - 8-Bit 20MHz OTP MCU, 3.5KB | Microchip
MPN: PIC16C64AT-20/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $8.1 | $81.00 |
| 100 | $7.2 | $720.00 |
| 500 | $6.4 | $3,200.00 |
| 1,000 | $5.75 | $5,750.00 |
PIC16C64AT-20/L Overview
What is a PIC16C OTP microcontroller? A microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, working RAM, and peripheral interfaces. The PIC16C family uses a Harvard-architecture RISC core that executes most instructions in a single clock cycle, making it well suited to real-time control. The “C” suffix denotes CMOS EPROM/OTP program memory - non-volatile, but write-once. Within the broader taxonomy, the PIC16C64A sits in this hierarchy: 8-bit MCU -> PIC16 family -> PIC16C6x sub-family -> PIC16C16C64A device -> OTP CMOS implementation.
Key features of the PIC16C64A include 33 I/O pins, three timer modules, a Capture/Compare/PWM (CCP) module, an 8-bit parallel slave port, and serial interfaces (SSP) that support both SPI and I²C. The device integrates power-on reset (POR), brown-out detect/reset (BOR), a watchdog timer (WDT) with its own on-chip RC oscillator, and a programmable code-protection fuse. Operating voltage spans 3.0 V to 5.5 V across the commercial 0 °C to +70 °C range, with industrial -40 °C to +85 °C variants available under different temperature suffixes.
Architecturally, the PIC16C64A uses a 14-bit instruction word and an 8-bit data path, allowing compact code density while keeping peripherals register-mapped. The 8-level hardware stack and 35-instruction set simplify assembly or C programming, and the CCP module provides PWM outputs for motor or LED control. The parallel slave port lets the device interface directly to an external 8-bit host bus, while the SSP peripheral supports both SPI and I²C master/slave modes.
Typical applications include industrial control panels, motor drive front-ends, embedded sensor hubs, and legacy upgrade / EOL replacement designs where a proven PIC16C6x footprint and toolchain are required. The PIC16C64AT-20/L is also widely used in educational and prototyping environments that target the PIC16C instruction set.
When designing with this part, verify that OTP programming is appropriate for the production volume - flashed (F-series) PIC16F variants are typically lower cost per unit and re-programmable. Confirm the 5V supply rail tolerance for analog peripherals and ensure the parallel slave port pin direction registers are correctly initialised in firmware.
This page synthesises distributor pricing, verified drop-in alternatives from the PIC16C6x family, and practical design notes that go beyond what the manufacturer datasheet alone provides.
Drop-in alternatives for PIC16C64AT-20/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 PIC16C64AT-20/L (same form factor and footprint) — differing in Instruction Set, Operating Temperature, Package, Program Memory Size, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C64A-20/L
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C64A-20I/L
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$3.1 / Unit
View Datasheet →PIC16C64AT-20E/L
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C64AT-10/L
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C64AT-20/PT
✅ Drop-In ⚠️ 参数待验证📋 Reference alternative (not in catalog)
PIC16C64AT-20/L Maximum Ratings & Electrical Characteristics
| Family | PIC® 16C |
| Core | 8-bit RISC |
| Core Architecture | Harvard |
| Max CPU Frequency | 20 MHz |
| Instruction Set | 35 instructions, mostly single-cycle |
| Instruction Word | 14-bit |
| Program Memory Type | OTP (One-Time Programmable) CMOS |
| Program Memory Size | 3.5 KB (2K x 14) |
| RAM Size | 128 bytes |
| I/O Pins | 33 |
| Timers | 3 (Timer0, Timer1, Timer2) |
| CCP Modules | 1 (Capture/Compare/PWM) |
| Serial Interfaces | SSP (SPI / I²C) |
| Parallel Slave Port | Yes (8-bit) |
| Operating Voltage | 3.0 V to 5.5 V |
| Operating Temperature | 0 °C to +70 °C (commercial) |
| Brown-out Reset | Yes |
| Power-on Reset | Yes |
| Watchdog Timer | Yes (with dedicated on-chip RC) |
| Package | 44-pin PLCC (J-Lead), 16.59 mm x 16.59 mm |
| Mounting Type | Surface Mount |
PIC16C64AT-20/L Pin Configuration
| Pin 1 | RA3/AN3/VREF+ — PORTA bit 3 / analog input 3 / voltage reference + |
| Pin 2 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 3 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 4 | OSC1/CLKIN — Crystal oscillator input / external clock in |
| Pin 5 | OSC2/CLKOUT — Crystal oscillator output / clock out (Fosc/4) |
| Pin 6 | VSS — Ground reference |
| Pin 7 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator out / Timer1 clock in |
| Pin 8 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator in / CCP2 output |
| Pin 9 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 output |
| Pin 10 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I²C clock |
| Pin 11 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I²C data |
| Pin 12 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 13 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 14 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 15 | VSS — Ground reference |
| Pin 16 | VDD — Positive supply voltage |
| Pin 17 | RB0/INT — PORTB bit 0 / external interrupt input |
| Pin 18 | RB1 — PORTB bit 1 |
| Pin 19 | RB2 — PORTB bit 2 |
| Pin 20 | RB3 — PORTB bit 3 |
| Pin 21 | RB4 — PORTB bit 4 |
| Pin 22 | RB5 — PORTB bit 5 |
| Pin 23 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 24 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 25 | VSS — Ground reference |
| Pin 26 | VDD — Positive supply voltage |
| Pin 27 | RE0/RD/AN5 — PORTE bit 0 / parallel slave port read / analog input 5 |
| Pin 28 | RE1/WR/AN6 — PORTE bit 1 / parallel slave port write / analog input 6 |
| Pin 29 | RE2/CS/AN7 — PORTE bit 2 / parallel slave port chip select / analog input 7 |
| Pin 30 | VDD — Positive supply voltage |
| Pin 31 | VSS — Ground reference |
| Pin 32 | OSC1/CLKIN — Crystal oscillator input / external clock in (alternate) |
| Pin 33 | OSC2/CLKOUT — Crystal oscillator output / clock out (alternate) |
| Pin 34 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 35 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 36 | RA2/AN2/VREF- — PORTA bit 2 / analog input 2 / voltage reference - |
| Pin 37 | RD0/PSP0 — PORTD bit 0 / parallel slave port bit 0 |
| Pin 38 | RD1/PSP1 — PORTD bit 1 / parallel slave port bit 1 |
| Pin 39 | RD2/PSP2 — PORTD bit 2 / parallel slave port bit 2 |
| Pin 40 | RD3/PSP3 — PORTD bit 3 / parallel slave port bit 3 |
| Pin 41 | RD4/PSP4 — PORTD bit 4 / parallel slave port bit 4 |
| Pin 42 | RD5/PSP5 — PORTD bit 5 / parallel slave port bit 5 |
| Pin 43 | RD6/PSP6 — PORTD bit 6 / parallel slave port bit 6 |
| Pin 44 | RD7/PSP7 — PORTD bit 7 / parallel slave port bit 7 |
Typical Applications
PIC16C64AT-20/L is suitable for 6 applications: Industrial Control Panels, Motor Drive Front-Ends, Embedded Sensor Hubs, Legacy EOL Replacement / Field Retrofit, Educational and Prototyping Boards, White-Goods Appliance Control.
Industrial Control Panels
The PIC16C64AT-20/L is well matched to industrial control panels that need deterministic 8-bit control. With its 20 MHz CPU and 200 ns instruction cycle, the device can scan a 32-input keypad matrix and refresh a multiplexed 7-segment display inside a tight 5 ms loop without firmware timing headaches. The 33 I/O pins drive relay coils, optocouplers and status LEDs directly, while the on-chip Capture/Compare/PWM (CCP) module produces the timing signals for proportional valve control or heating-element PWM. Brown-out reset (BOR) and a hardware watchdog timer (WDT) reset the MCU after supply glitches or firmware lock-ups, which is essential on factory floors where 24 V DC supplies are common and noisy. The 44-pin PLCC socketed package simplifies field replacement, so service technicians can swap a failed MCU without re-soldering. Program memory is OTP at 3.5 KB, which is adequate for fixed-function ladder-replacement logic and short messaging protocols.
Recommended
Motor Drive Front-Ends
Small brushed-DC and unipolar stepper motor controllers benefit from the PIC16C64AT-20/L’s on-chip CCP/PWM module and three timers. The 20 MHz instruction cycle produces PWM frequencies up to 78 kHz at 10-bit resolution (Fosc / 1024), which is more than enough bandwidth to drive MOSFET half-bridges without audible switching noise. The 33 digital I/O pins handle Hall-sensor inputs, end-stop switches, encoder feedback and direction logic, while the SSP peripheral supports I²C communication with companion sensors such as the Microchip MCP9808 thermal monitor or external EEPROMs. The PIC16C64A’s 128-byte RAM is sufficient for closed-loop PI control variables, and the 3.5 KB OTP program memory holds the entire state machine. Designers should add TVS diodes and a flyback structure across the motor terminals to protect the MCU from inductive kick-back on the I/O pins.
Recommended
Embedded Sensor Hubs
The PIC16C64AT-20/L functions as a low-cost sensor hub that aggregates analogue signals and forwards them over SPI or I²C. The on-chip SSP block supports both master and slave modes at up to 400 kHz I²C (Fast-mode) and SPI at 5 MHz, which is sufficient for typical sensor networks. With 33 I/O and an internal 8-bit parallel slave port, the MCU can attach an external 8-bit ADC or share the bus with a host processor for data forwarding. Brown-out reset and power-on reset ensure deterministic startup, while the watchdog timer recovers from firmware stalls in unattended installations. The commercial 0 °C to +70 °C operating range covers most indoor monitoring applications such as HVAC duct sensing, smart-building telemetry and energy-meter pulse counting. For battery-powered nodes, designers can drop the CPU to 4 MHz to reduce active current; at that clock the PIC16C64A consumes only a few milliamps.
Recommended
Legacy EOL Replacement / Field Retrofit
Many products in the field use PIC16C6x-family OTPs and now need an exact-form replacement. The PIC16C64AT-20/L in a 44-pin PLCC can be socketed into a legacy PCB without any layout change, restoring original firmware behaviour and avoiding re-certification cost. Its 8-bit RISC core, 35-instruction set and register file are identical to the original silicon, so legacy assembly code or compiled C code runs unchanged. Industrial-grade equivalents such as PIC16C64A-20I/L cover -40 °C to +85 °C and are drop-in when the original was an industrial grade. For long-term sustainability, designers can migrate firmware to a flash-based PIC16F877-20I/L in the same 44-pin PLCC footprint using the PICkit 3 ICD toolchain, then keep the original PIC16C64AT-20/L for spare-parts inventory until stock is exhausted.
Recommended
Educational and Prototyping Boards
The PIC16C64AT-20/L is widely adopted in university curricula and DIY prototyping because the 44-pin PLCC package fits standard 44-pin PLCC sockets, making board swap-out trivial for student labs. With 33 I/O pins, three timers, an on-chip PWM and an SSP peripheral, the MCU covers the majority of undergraduate coursework topics - GPIO, timers, interrupts, PWM, SPI and I²C - using a single chip. The 3.5 KB OTP program memory forces students to write efficient code, while the 14-bit instruction word exposes them to the RISC paradigm. The PIC16C64AT-20/L’s commercial 0 °C to +70 °C range suits indoor lab benches and avoids the cost of industrial-grade parts. Many legacy PIC16C6x development kits - including the PICSTART Plus and original ICD units - target this part, so used tools and reference designs remain abundant on the second-hand market.
Recommended
White-Goods Appliance Control
Washing machines, dishwashers and small kitchen appliances historically used the PIC16C6x family because of its deterministic real-time behaviour and on-chip peripherals. The PIC16C64AT-20/L delivers 20 MHz of compute for keypad scanning, water-level sensor reading, motor PWM control and triac-fired heater timing, all from a single MCU. Its CCP module produces the zero-crossing synchronised drive needed for triac-based heater or valve control, while the brown-out reset protects the MCU from mains-derived supply dips during compressor inrush. Program memory is OTP, which keeps per-unit cost low in high-volume white-goods production. Engineers designing new white-goods products today should evaluate the flash-based PIC16F877A-I/L, which is pin-compatible in 44-pin PLCC and supports in-circuit re-programming for late-stage firmware bug fixes during production.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C64AT-20/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C64A-20/L | PIC16C64A-20I/L | PIC16C64AT-20E/L | PIC16C64AT-10/L |
|---|---|---|---|---|---|
| Package | 44-PLCC (J-Lead), 16.59 x 16.59 mm | 44-PLCC (J-Lead) - same | 44-PLCC (J-Lead) - same | 44-PLCC (J-Lead) - same | 44-PLCC (J-Lead) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max CPU Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 10 MHz (-50%) |
| Program Memory | 3.5 KB (2K x 14) OTP | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP |
| RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Operating Temperature | 0 °C to +70 °C (commercial) | 0 °C to +70 °C | -40 °C to +85 °C (industrial) | -40 °C to +85 °C (extended) | 0 °C to +70 °C |
| Packaging | Tape & Reel (T suffix) | Tray | Tray | Tape & Reel | Tape & Reel |
Key Differentiators
- OTP-only memory for write-once security (vs PIC16F877-20I/L (flash-based))
- 44-pin PLCC socketed footprint for field-replaceable designs (vs PIC16F877-20I/P (40-pin PDIP))
- On-chip parallel slave port (PSP) for 8-bit host expansion (vs PIC16C62BT-20I/SO (28-pin SOIC))
Design Notes
Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of every VDD pin (the PIC16C64A has three VDD pins: 16, 26, 30 and one VSS: 15, 25, 31). Add a bulk 10 µF tantalum or aluminium-polymer cap near the IC for transient suppression. Brown-out reset (BOR) is enabled by configuration fuse - leaving it disabled can cause EEPROM corruption on noisy supplies.
PIC16C64AT-20/L is OTP - code is write-once. Verify the entire firmware image with the Microchip PICkit 3 and a UV-windowed PIC16C64A JW sample before committing to a production run. Confirm the configuration bits (oscillator, watchdog, code-protect, brown-out) match the schematic - a wrong WDT setting can lock the MCU in a reset loop with no debug visibility.
Route the crystal traces (OSC1/OSC2) as short, matched-length pairs and guard them with a GND keep-out zone to reduce EMI pickup. Place the 22 pF crystal-load capacitors close to the MCU pins, not near other high-frequency nets. If the parallel slave port is used, isolate the PORTD/PSP traces from PORTA/C/E to prevent bus contention during initialisation.
Compliance Information
PIC16C64AT-20/L is an OTP legacy MCU marked NCNR (Not Recommended for New Designs). RoHS, REACH and lead-free status were not present in the verified distributor data set and are listed as 'unknown' rather than guessed; engineers should request the latest material declaration from Microchip before placing volume orders.
