PIC16C64A-20I/L - 8-Bit 20MHz OTP MCU 3.5KB | Microchip
MPN: PIC16C64A-20I/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.85 | $4.85 |
| 10 | $4.36 | $43.60 |
| 100 | $3.88 | $388.00 |
| 500 | $3.49 | $1,745.00 |
| 1,000 | $3.1 | $3,100.00 |
PIC16C64A-20I/L Overview
A microcontroller (MCU) is a single-chip computer containing a CPU, RAM, non-volatile program memory, and peripherals such as timers, interrupts, and I/O. PIC microcontrollers from Microchip use a Harvard RISC architecture that separates program and data buses, enabling most instructions to execute in one clock cycle. The PIC16C64A belongs to the mid-range PIC family, sitting between the baseline PIC10/12/16 and the enhanced PIC18 in features and complexity.
Key differentiating features include 20 MHz operation, an 8-bit timer/counter with 8-bit prescaler, a 16-bit timer/counter, an analog comparator, a Watchdog Timer with its own on-chip RC oscillator for reliable operation, and synchronous/asynchronous serial port (SSP/SCI) capability. Power consumption is rated at 15 mA typical at 5 V, 4 MHz, and as low as 1 mA typical at 3 V, 32 kHz - a fully-static design that allows the clock to be stopped without losing register contents.
The PIC16C64A implements Microchip's enhanced mid-range architecture with EPROM-based program storage, allowing prototype and small-volume manufacturing using a windowed or OTP package. The 44-pin PLCC variant (industrial -40 C to +85 C, indicated by the -20I/L suffix) is widely used in embedded control boards, instrumentation front-ends, and industrial automation controllers.
Typical applications include industrial control logic, sensor signal conditioning front-ends, motor-control PWM drivers, UART-based communication bridges, and legacy embedded products requiring a proven 8-bit PIC core. It is also deployed as a slave controller in distributed I/O systems where deterministic single-cycle instruction execution simplifies timing analysis.
When using this part, allocate sufficient decoupling (100 nF + 10 uF) close to VDD/VDD2/VSS pairs, ensure MCLR is pulled high through 10-100 kohm with a decoupling capacitor for reliable resets, and reserve the OSC1/OSC2 pins for the chosen crystal or resonator configuration. The OTP nature of the program memory means code must be correct before programming - consider PIC16F64A flash variant for development iteration.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, helping procurement and engineering teams compare the PIC16C64A-20I/L against current Microchip PIC16C6X and pin-compatible PIC16C65B family options.
Drop-in alternatives for PIC16C64A-20I/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 PIC16C64A-20I/L (same form factor and footprint) — differing in Instruction Set, Mounting Type, Package, Program Memory Size, RAM Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C65B-20I/L
✅ Drop-In✓ In Stock
$8.4 / Unit
View Datasheet →PIC16C65A-20I/L
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →PIC16C64A-04I/L
✅ Drop-In✓ In Stock
$4.5 / Unit
View Datasheet →PIC16C66-20I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C67-20I/L
✅ Drop-In✓ In Stock
$6.75 / Unit
View Datasheet →PIC16C64A-20I/L Maximum Ratings & Electrical Characteristics
| Series | PIC 16C |
| Core Processor | PIC |
| Core Size | 8-Bit |
| Maximum Clock Speed | 20 MHz |
| Program Memory Size | 3.5 KB (2K x 14) OTP |
| RAM Size | 128 x 8 bytes |
| Number of I/O Pins | 33 |
| Supply Voltage (VDD) | 4.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 44-pin PLCC (16.59 x 16.59 mm) |
| Mounting Type | Surface Mount |
| Program Memory Type | OTP EPROM |
| Architecture | Harvard RISC, fully static |
| Instruction Set | 35 single-word instructions |
| Timer/Counters | 1 x 8-bit + 1 x 16-bit |
| Peripherals | Brown-out Detect, Watchdog Timer, SSP, USART |
| Connectivity | I2C, SPI, UART |
PIC16C64A-20I/L Pin Configuration
| Pin 1 | MCLR — Master Clear (Reset) input, active low |
| Pin 2 | RA0 — PORTA bit 0 (digital I/O) |
| Pin 3 | RA1 — PORTA bit 1 (digital I/O) |
| Pin 4 | RA2 — PORTA bit 2 (digital I/O) |
| Pin 5 | RA3 — PORTA bit 3 (digital I/O) |
| Pin 6 | RA4 — PORTA bit 4 (digital I/O, T0CKI) |
| Pin 7 | RA5 — PORTA bit 5 (digital I/O, SS) |
| Pin 8 | RE0 — PORTE bit 0 (digital I/O, AN5) |
| Pin 9 | RE1 — PORTE bit 1 (digital I/O, AN6) |
| Pin 10 | RE2 — PORTE bit 2 (digital I/O, AN7) |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1 — Oscillator input / external clock |
| Pin 14 | OSC2 — Oscillator output |
| Pin 15 | RC0 — PORTC bit 0 (digital I/O, T1OSO) |
| Pin 16 | RC1 — PORTC bit 1 (digital I/O, T1OSI) |
| Pin 17 | RC2 — PORTC bit 2 (digital I/O, CCP1) |
| Pin 18 | RC3 — PORTC bit 3 (digital I/O, SCL/SCL1) |
| Pin 19 | RD0 — PORTD bit 0 (digital I/O, PSP0) |
| Pin 20 | RD1 — PORTD bit 1 (digital I/O, PSP1) |
| Pin 21 | RD2 — PORTD bit 2 (digital I/O, PSP2) |
| Pin 22 | RD3 — PORTD bit 3 (digital I/O, PSP3) |
| Pin 23 | RC4 — PORTC bit 4 (digital I/O, SDI/SDA) |
| Pin 24 | RC5 — PORTC bit 5 (digital I/O, SDO) |
| Pin 25 | RC6 — PORTC bit 6 (digital I/O, TX/CK) |
| Pin 26 | RC7 — PORTC bit 7 (digital I/O, RX/DT) |
| Pin 27 | RD4 — PORTD bit 4 (digital I/O, PSP4) |
| Pin 28 | RD5 — PORTD bit 5 (digital I/O, PSP5) |
| Pin 29 | RD6 — PORTD bit 6 (digital I/O, PSP6) |
| Pin 30 | RD7 — PORTD bit 7 (digital I/O, PSP7) |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage |
| Pin 33 | RB0 — PORTB bit 0 (digital I/O, INT) |
| Pin 34 | RB1 — PORTB bit 1 (digital I/O) |
| Pin 35 | RB2 — PORTB bit 2 (digital I/O) |
| Pin 36 | RB3 — PORTB bit 3 (digital I/O) |
| Pin 37 | RB4 — PORTB bit 4 (digital I/O) |
| Pin 38 | RB5 — PORTB bit 5 (digital I/O) |
| Pin 39 | RB6 — PORTB bit 6 (digital I/O, PGC) |
| Pin 40 | RB7 — PORTB bit 7 (digital I/O, PGD) |
| Pin 41 | VDD — Positive supply voltage |
| Pin 42 | VSS — Ground reference |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C64A-20I/L is suitable for 6 applications: Industrial Control Logic, Sensor Signal Conditioning Front-End, Motor Control PWM Driver, UART Communication Bridge, Legacy Embedded Controller Maintenance, Display Driver Controller.
Industrial Control Logic
The PIC16C64A-20I/L fits industrial control logic boards because of its 33 digital I/O pins, 20 MHz deterministic single-cycle instruction execution, and industrial -40 C to +85 C temperature rating. The Harvard RISC architecture ensures predictable 200 ns instruction timing, which simplifies PLC ladder-replacement firmware. Power consumption of 15 mA typical at 5 V/4 MHz allows fanless DIN-rail mounting. Brown-out detect and watchdog timer add resilience against noisy 24 V bus-rail transients. Drop the part into legacy PIC16C6X 44-pin PLCC sockets without board rework.
Recommended
Sensor Signal Conditioning Front-End
The PIC16C64A-20I/L serves as a sensor signal conditioning front-end by reading analog inputs through an external ADC over SPI and forwarding calibrated values over USART. Its 20 MHz clock gives plenty of bandwidth for oversampling and digital filtering. The 128-byte RAM is sufficient for 16-tap FIR coefficients and a circular buffer. The OTP memory allows tamper-resistant firmware that cannot be read back, ideal for factory-calibrated transducers. Use PIC16C65B for designs needing two PWM outputs to drive excitation bridges.
Recommended
Motor Control PWM Driver
The PIC16C64A-20I/L drives brushed DC and stepper motors via its CCP module generating 10-bit PWM at up to 20 kHz. At 20 MHz clock, PWM resolution is 10 bits at 19.5 kHz, which is adequate for DC motor speed loops and stepper microstepping. The industrial temperature range supports under-hood automotive and factory-floor motor cabinets. Brown-out detect prevents motor coasting during voltage sag. For H-bridge or 3-phase topologies, migrate to PIC16C65A which adds a second CCP module on the same PLCC-44 footprint.
Recommended
UART Communication Bridge
The PIC16C64A-20I/L bridges between UART, SPI, and I2C peripherals thanks to its integrated USART, SSP (SPI/I2C) module, and 20 MHz clock. Firmware can implement Modbus RTU slave conversion to SPI sensor hubs at 115200 bps without CPU loading issues. The 128-byte RAM holds Modbus registers; the 3.5 KB OTP program memory supports protocol stacks with command parsing. Industrial temperature rating supports outdoor RS-485 to sensor-bus bridges. Migrate to PIC16F88 for designs needing flash-based firmware updates in the field.
Recommended
Legacy Embedded Controller Maintenance
The PIC16C64A-20I/L is used to maintain installed-base embedded controllers where PCB redesign is cost-prohibitive. The 44-pin PLCC socket compatibility allows direct swap of failed parts without board rework. Microchip marks it NRND, so production systems should be transitioned to PIC16C65B or PIC16F877A while field repairs continue using PIC16C64A-20I/L. The OTP memory guarantees firmware cannot be reverse-engineered, preserving OEM IP. Procure stock for known-good replacements and validate against the original BOM.
Recommended
Display Driver Controller
The PIC16C64A-20I/L drives character LCD modules and small graphic displays via bit-banged I/O or SPI. The 33 I/O pins easily cover 4-bit LCD data, RS, RW, E, backlight PWM, and 5 keypad scan lines. The 20 MHz clock enables glitch-free SPI to ST7565-based 128x64 LCDs at 4 MHz bit rate. Industrial temperature rating supports outdoor kiosks and instrument panels. For designs needing USB or full-speed USB-to-UART bridges, migrate to PIC16C65B plus an external MCP2200 bridge IC.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C64A-20I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65B-20I/L | PIC16C65A-20I/L | PIC16C64A-04I/L | PIC16C64A-20I/PT |
|---|---|---|---|---|---|
| Package | 44-pin PLCC | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin TQFP - different |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Speed | 20 MHz | 20 MHz | 20 MHz | 4 MHz | 20 MHz |
| Program Memory Size | 3.5 KB OTP | 7 KB OTP | 4 KB OTP | 3.5 KB OTP | 3.5 KB OTP |
| RAM Size | 128 bytes | 192 bytes | 192 bytes | 128 bytes | 128 bytes |
| Number of I/O Pins | 33 | 33 | 33 | 33 | 33 |
| CCP/PWM Modules | 1 | 2 | 2 | 1 | 1 |
| Operating Voltage | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 2.5 V to 6.0 V | 4.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| Lifecycle Status | NRND | Active (recommended) | NRND | NRND | NRND |
Key Differentiators
- Single CCP/PWM module only (vs PIC16C65A-20I/L)
- 3.5 KB program memory with 128-byte RAM (vs PIC16C65B-20I/L)
- OTP EPROM program memory (vs PIC16F877A-I/L)
- 44-pin PLCC industrial temperature variant (vs PIC16C64A-04I/L)
Design Notes
Decouple both VDD/VSS pairs on the 44-pin PLCC with a 100 nF ceramic capacitor placed within 5 mm of each pair, plus a bulk 10 uF tantalum or aluminum polymer cap on the main supply rail. According to Microchip PIC16C6X datasheet, the dual VDD/VSS pairs serve analog and digital sections separately - bypassing both minimizes digital switching noise coupling into the analog comparator reference. For industrial 24 V-bus powered designs, add a TVS diode and series ferrite on the input to the 5 V LDO that feeds VDD.
Do not assume the OTP windowed ceramic package variant supports in-circuit reprogramming - OTP memory is one-time-programmable. According to the PIC16C6X datasheet, attempting to erase UV-windowed parts requires 30 minutes of UV-C exposure at 15,000 uW/cm^2, but standard OTP parts have no erasure path. For development iteration, use the flash-based PIC16F877A on the same PLCC-44 footprint, then migrate the verified firmware to PIC16C64A-20I/L for production.
Route the OSC1/OSC2 traces short and symmetric, and keep them away from high-current switching traces such as relay drivers or motor PWM outputs. According to Microchip hardware design guidelines, the crystal oscillator is sensitive to capacitive loading - keep the trace capacitance below 15 pF. Add a ground guard ring around the crystal and its loading capacitors to prevent radiated noise injection from adjacent PWM or relay-switching traces.
Place the MCLR pull-up resistor (10 kohm typical) close to the MCLR pin with a 100 nF decoupling capacitor to VSS. According to PIC16C6X datasheet, the MCLR pin is sensitive to noise-induced resets in industrial environments. For high-noise applications, add a series ferrite bead and a clamping TVS diode rated for 5 V operation to prevent brown-out events caused by ESD or surge transients on the reset line.
Compliance Information
PIC16C64A predates RoHS; lead-free status not explicitly stated in datasheet. AEC-Q100 not applicable (industrial MCU, not automotive-qualified).
