PIC16C64AT-04E/L - 8-Bit OTP MCU 4MHz 3.5KB EPROM PLCC | Microchip
MPN: PIC16C64AT-04E/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.5 | $9.50 |
| 10 | $8.55 | $85.50 |
| 100 | $7.62 | $762.00 |
| 500 | $6.84 | $3,420.00 |
| 1,000 | $6.1 | $6,100.00 |
PIC16C64AT-04E/L Overview
An 8-bit OTP microcontroller is a single-chip computer built around an 8-bit data path and a Harvard architecture with separate program and data memories. OTP (One-Time Programmable) EPROM is a non-volatile memory that can be written once using an EPROM programmer and exposed UV light, then retains its contents without power. Within the broader taxonomy, this part sits as: PIC16C64AT-04E/L -> PIC16C64A -> PIC16C6X family -> PIC16 -> 8-bit PIC microcontroller -> microcontroller (MCU) -> embedded processor -> semiconductor. OTP microcontrollers are positioned between mask-ROM MCUs (lowest cost at high volume) and Flash MCUs (reprogrammable, higher per-unit cost), making them well suited for low-to-medium volume production where code changes between builds are not required.
Key features include 35 single-word instructions, single-cycle execution for most instructions (branches are two-cycle), a 14-bit instruction word, and a peripheral set typical of the PIC16C6X series: timers, a synchronous serial port (SSP) module, USART, capture/compare/PWM, and analog and digital I/O. The PIC16C64AT-04E/L is rated for 4 MHz maximum clock frequency, supports DC to 4 MHz operating speed, and operates from a single 5 V supply. The 33 I/O pins provide ample digital connectivity for keypad scanning, LED driving, and parallel bus interfaces in cost-sensitive embedded designs.
From an architectural standpoint, the PIC16C64A uses a RISC core with a 14-bit-wide program memory bus and an 8-bit-wide data memory bus, allowing instruction fetch and data access in a single machine cycle for most opcodes. The integrated peripheral set mirrors the earlier PIC16C64 with added enhancements, and the OTP EPROM window package variant (JW) supports prototype and low-volume debugging via UV erasure. CMOS static design means clock can be stopped without losing register state, simplifying power-managed designs.
Typical applications include industrial control panels, appliance control boards, automotive body electronics (pre-CAN modules), HVAC controllers, security keypads, and simple sensor interfaces where fixed firmware and cost-sensitive BOMs are priorities over Flash-based reprogrammability. The 44-pin PLCC package remains common in legacy industrial equipment where socketed replacement simplifies field service.
When designing with this part, note that OTP parts cannot be reprogrammed in-circuit; firmware must be fully validated on a JW (windowed) or Flash equivalent before committing to production. Verify oscillator loading capacitors against the chosen crystal and ensure adequate decoupling on VDD/SS to suppress digital switching noise on adjacent analog sections.
This page synthesizes distributor pricing, drop-in PIC16C64A family alternatives, and practical design notes beyond the manufacturer datasheet to support sourcing and engineering decisions for legacy and new designs.
Drop-in alternatives for PIC16C64AT-04E/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-04E/L (same form factor and footprint) — differing in Mounting Type, RAM Size, Operating Temperature Range, Program Memory Size, Core Processor.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C64A-04E/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C64A-04I/L
✅ Drop-In✓ In Stock
$4.5 / Unit
View Datasheet →PIC16C64A-04E/PQ
✅ Drop-In✓ In Stock
$5.4 / Unit
View Datasheet →PIC16C64AT-04E/PT
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →PIC16C64A-20E/L
✅ Drop-In✓ In Stock
$8.97 / Unit
View Datasheet →PIC16C64A-20I/L
✅ Drop-In✓ In Stock
$3.1 / Unit
View Datasheet →PIC16C64AT-04E/L Maximum Ratings & Electrical Characteristics
| Core | 8-bit PIC RISC |
| Series | PIC16C6X (PIC16C64A) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 3.5 KB (2K x 14) |
| RAM Size | 128 bytes |
| Number of I/O Pins | 33 |
| Maximum Clock Frequency | 4 MHz |
| Operating Speed | DC to 4 MHz |
| Instruction Set | 35 single-word instructions (14-bit) |
| Supply Voltage (VDD) | 5 V (typical) |
| Oscillator Type | External |
| Package | 44-pin PLCC (J-lead) |
| Packaging | Tape & Reel (TR) |
| Operating Temperature Range | -40C to +125C (extended) |
| Mounting Type | Surface Mount |
PIC16C64AT-04E/L Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / analog input 3 / voltage reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/SS/AN4 — PORTA bit 5 / SSP slave select / analog input 4 |
| Pin 8 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 9 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM1 |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / SSP clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — PORTC bit 4 / SSP data in / I2C data |
| Pin 15 | RC5/SDO — PORTC bit 5 / SSP data out |
| Pin 16 | RC6/TX/CK — PORTC bit 6 / USART transmit / USART clock |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / USART receive / USART data |
| Pin 18 | VSS — Ground |
| Pin 19 | VDD — Positive supply (5 V) |
| Pin 20 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 21 | RB1 — PORTB bit 1 |
| Pin 22 | RB2 — PORTB bit 2 |
| Pin 23 | RB3/PGM — PORTB bit 3 / LVP programming |
| Pin 24 | RB4 — PORTB bit 4 |
| Pin 25 | RB5 — PORTB bit 5 |
| Pin 26 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 27 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 28 | NC — Not connected (per datasheet) |
| Pin 29 | NC — Not connected (per datasheet) |
| 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 |
| Pin 39 | VDD — Positive supply (5 V) |
| Pin 40 | RE0/RD/AN5 — PORTE bit 0 / parallel slave port read / analog input 5 |
| Pin 41 | RE1/WR/AN6 — PORTE bit 1 / parallel slave port write / analog input 6 |
| Pin 42 | RE2/CS/AN7 — PORTE bit 2 / parallel slave port chip select / analog input 7 |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C64AT-04E/L is suitable for 7 applications: Industrial Control Panels, Appliance Control Boards, Automotive Body Electronics (Pre-CAN), HVAC Controllers, Security Keypads and Access Panels, Sensor Interface Modules, Legacy Equipment Service Replacement.
Industrial Control Panels
The PIC16C64AT-04E/L fits industrial control panel HMIs and discrete I/O subsystems where fixed firmware, cost-sensitive BOMs, and long-term parts availability matter more than reprogrammability. With 33 digital I/O pins, the part can directly drive 7-segment displays, scan 4x4 keypads, and toggle relay drivers without external glue logic. Its 3.5 KB OTP EPROM is adequate for typical state-machine firmware driving menus, mode logic, and indicator lamps. The 4 MHz clock yields a 1 microsecond instruction cycle, sufficient for 10 ms contact debounce loops and UART-driven operator-panel interfaces at 9600 baud. The extended -40C to +125C temperature rating ensures reliable operation inside sealed control cabinets near motors and heaters.
Recommended
Appliance Control Boards
The PIC16C64AT-04E/L is well suited for washing machine, dishwasher, and oven control boards where the firmware is finalized at design freeze and never needs field update. OTP EPROM at 3.5 KB holds appliance state machines including wash cycles, temperature profiles, and user interface menus. The 33 I/O pins accommodate multiple LED indicators, segment displays, keypads, triac-fired heater controls, and motor direction relays through opto-isolated drivers. The 5 V operation matches standard linear regulators used in white-goods power supplies. Compared to Flash parts, the OTP device offers lower unit cost at the volumes typical of major appliance production runs of 50K-500K units annually.
Recommended
Automotive Body Electronics (Pre-CAN)
The PIC16C64AT-04E/L handles body electronics modules in older vehicles without networking requirements, including seat controllers, mirror adjusters, and lighting modules. With 33 I/O pins, the part can read multiple switch inputs, drive several lamp and motor outputs through MOSFET drivers, and run PWM for dimming. The extended -40C to +125C temperature range meets under-dash automotive thermal requirements. The OTP EPROM prevents unauthorized firmware modification, an advantage for OEM-locked automotive subsystem designs. For CAN-bus modules, however, designers should select PIC18F family parts with integrated CAN peripherals instead.
Recommended
HVAC Controllers
The PIC16C64AT-04E/L is ideal for low-to-mid-end HVAC thermostat and zone damper controllers where deterministic firmware and modest peripheral needs dominate. The 128-byte RAM supports small PID control loops for temperature regulation, and the 3.5 KB EPROM accommodates scheduling logic, setpoint menus, and HVAC state machines. The 33 I/O pins handle multiple temperature sensor inputs through the analog comparator, LCD segment driving, relay outputs for compressor and fan stages, and keypads for user setpoint adjustment. Operating from a single 5 V rail simplifies the power tree from a 24 VAC HVAC transformer through a half-wave rectifier and LDO.
Recommended
Security Keypads and Access Panels
The PIC16C64AT-04E/L powers security keypads and access control panels where OTP firmware prevents reverse-engineering of credential handling logic. The 33 I/O pins scan 4x4 or 5x5 matrix keypads directly, drive status LEDs and buzzer outputs, and interface with magnetic-stripe or Wiegand card readers through serial protocols. The PIC16C6X USART supports 9600 to 115200 baud communication with central access management panels. With 3.5 KB of program memory, the firmware holds credential tables, lockout timers, and audit log buffering. The extended temperature range supports outdoor-mounted access panels in cold climates.
Recommended
Sensor Interface Modules
The PIC16C64AT-04E/L serves as a smart sensor interface front-end, digitizing analog sensor signals and presenting them via UART, SPI, or I2C to a host controller. With 33 I/O pins, multiple sensors (temperature, humidity, pressure switches) can be multiplexed into the PIC16C6X ADC and comparator inputs. The 3.5 KB EPROM fits linearization tables and calibration constants for industrial sensors. The 4 MHz clock rate is sufficient to poll sensors at 100 Hz with digital filtering overhead. OTP EPROM locks calibration coefficients against field tampering in metering and process-control applications.
Recommended
Legacy Equipment Service Replacement
The PIC16C64AT-04E/L is a critical service replacement part for installed industrial, medical, and telecom systems designed in the late 1990s that require identical pinout and timing characteristics. With the part in NRND status, sourcing becomes critical for customers maintaining fleets of legacy equipment. The 44-pin PLCC socket mount allows field service technicians to swap a failed MCU without desoldering, drastically reducing mean-time-to-repair. Distributors specializing in legacy Microchip stock carry reels for service contracts. Designers should not select it for new products but should retain it as a qualified service part with documented lifecycle status.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C64AT-04E/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C64A-04E/L | PIC16C64A-04I/L | PIC16C64A-04E/PQ | PIC16C64A-20E/L | PIC16C64A-20I/L |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin PLCC | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin PLCC - same | 44-pin PLCC - same |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz |
| Program Memory | 3.5 KB (2K x 14) OTP EPROM | 3.5 KB OTP EPROM | 3.5 KB OTP EPROM | 3.5 KB OTP EPROM | 3.5 KB OTP EPROM | 3.5 KB OTP EPROM |
| RAM Size | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| Temperature Range | -40C to +125C (Extended) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +125C (Extended) | -40C to +85C (Industrial) |
| Packaging Format | Tape & Reel (TR) | Tray | Tube | Tape & Reel (PQ) | Tube | Tube |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND | NRND |
Key Differentiators
- Tape-and-reel packaging for high-volume SMD assembly (vs PIC16C64A-04E/L (tray))
- Extended -40C to +125C operating temperature (vs PIC16C64A-04I/L (industrial -40C to +85C))
- Higher throughput option exists in same package (vs PIC16C64A-20E/L (20 MHz grade))
Design Notes
Estimated: At 4 MHz clock and 5 V supply, the PIC16C64AT-04E/L core draws approximately 5-10 mA depending on enabled peripherals and I/O loading. Place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pair (there are two pairs on the 44-pin PLCC: pins 19/18 and 39/38), and a single 10 uF bulk capacitor on the supply rail near the MCU. For battery-backed designs, switch to sleep mode via the SLEEP instruction to reduce current to under 2 uA typical - the brown-out reset circuit must be enabled to ensure clean wake-up.
The 44-pin PLCC package uses J-leads that are socket-friendly for field service. When laying out the PCB, reserve a footprint that accepts both a soldered PLCC and a through-hole PLCC socket (3M or similar), so prototypes can use socketed MCU swaps and production can solder directly. Keep oscillator traces short (<10 mm), guard the crystal with a ground ring, and route OSC1/OSC2 away from switching signals to avoid clock jitter. PORTE analog inputs (RE0-RE2) should be guarded with ground pour to minimize crosstalk from adjacent digital lines.
OTP EPROM parts cannot be re-programmed - verify your firmware on a PIC16C64A/JW (CERDIP windowed) prototype before committing to the OTP production part. According to the silicon errata, some PIC16C64A devices exhibit anomalous behavior in the SSP module; check Microchip silicon errata documents for the specific date code before locking firmware. The ICSP programming pins (RB6/RB7) and MCLR must be accessible in-circuit for programming; do not load them with heavy capacitance that prevents clean programming voltage transitions.
Compliance Information
RoHS and REACH compliance per Microchip material declaration. AEC-Q100 not qualified - use PIC16F family automotive parts for vehicle applications. Lead-free PLCC package is standard; halogen-free status not explicitly confirmed in distributor data.
