PIC16C64AT-04/PT - 8-bit OTP MCU, 3.5KB, 33 I/O, TQFP-44 | Microchip
MPN: PIC16C64AT-04/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.2 | $162.00 |
| 100 | $14.1 | $1,410.00 |
| 500 | $12.85 | $6,425.00 |
| 1,000 | $11.4 | $11,400.00 |
PIC16C64AT-04/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, volatile data memory, and programmable I/O peripherals on one silicon die. The PIC16CXX family, announced in the early 1990s, was the first to combine Harvard architecture, RISC instruction set, CMOS process, and OTP program memory, becoming the industry reference for low-cost embedded control. Within the broader taxonomy, this part sits at: PIC16C64A -> PIC16CXX -> PIC16 family -> 8-bit MCU -> microcontroller -> embedded processor -> semiconductor IC. Pin-compatible second sources include PIC16C64A (no A-suffix die revision) and PIC16C642 (lower-pin-count variant).
Key features include 35 single-word instructions, a 14-bit instruction word, an 8-level hardware stack, two 8-bit timer/counters, a Watchdog Timer with on-chip RC oscillator, programmable code protection, an analog comparator, and a synchronous serial port (SSP). The device operates from 4.0 V to 6.0 V over -40 C to +85 C (industrial) or 0 C to +70 C (commercial).
Architecturally, the PIC16C64A uses a RISC pipeline with a two-stage instruction fetch/execute, two hardware register banks for fast context save, and a wide variety of interrupt sources. The T-suffix indicates tape-and-reel packaging, the -04 indicates the 4 MHz speed grade, and the /PT suffix denotes the 44-pin TQFP package.
Typical applications include industrial control, sensor interfacing, low-power embedded systems, automotive in-cabin modules, and legacy equipment maintenance. Choose this part when you need to sustain production of a proven design rather than redesign around newer silicon.
When laying out the PCB, follow Microchip appnote AN585 for TQFP-44 land pattern recommendations. Decouple each VDD/VSS pair with a 100 nF ceramic capacitor placed within 5 mm of the pins, and assign MCLR/VPP to a dedicated test point for in-circuit programming.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the standalone manufacturer datasheet, supporting rapid sourcing decisions for production and field replacement.
Drop-in alternatives for PIC16C64AT-04/PT — 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-04/PT (same form factor and footprint) — differing in Package, Program Memory Type, Timers, Operating Temperature Range, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C64A-04/PT
✅ Drop-In✓ In Stock
$5.7 / Unit
View Datasheet →PIC16C64A-10/PT
✅ Drop-In✓ In Stock
$2.97 / Unit
View Datasheet →PIC16C64A-20/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C64A-04E/PT
✅ Drop-In✓ In Stock
$7.35 / Unit
View Datasheet →PIC16C64A-04I/PT
✅ Drop-In✓ In Stock
$4.61 / Unit
View Datasheet →PIC16C64AT-04/PT Maximum Ratings & Electrical Characteristics
| Product Family | PIC16CXX |
| Core | 8-bit PIC RISC |
| 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 |
| CPU Speed | 4 MHz (4 MIPS) |
| Instruction Word | 14 bits |
| Hardware Stack | 8 levels |
| Timers | 2 x 8-bit Timer/Counter |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Analog Comparator | Yes |
| Synchronous Serial Port (SSP) | Yes |
| Supply Voltage (Vcc) | 4.0 V to 6.0 V |
| Operating Temperature Range | -40 C to +85 C (industrial) |
| Package | 44-pin TQFP (PT), 10x10 mm |
| Mounting Type | Surface Mount |
| Speed Grade | -04 (4 MHz) |
| Packaging | Tape and Reel (T-suffix) |
PIC16C64AT-04/PT Pin Configuration
| Pin 1 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 2 | RA0 — Port A bit 0 (bidirectional I/O) |
| Pin 3 | RA1 — Port A bit 1 (bidirectional I/O) |
| Pin 4 | RA2 — Port A bit 2 (bidirectional I/O) |
| Pin 5 | RA3 — Port A bit 3 (bidirectional I/O) |
| Pin 6 | RA4/T0CKI — Port A bit 4 / Timer0 clock input |
| Pin 7 | RA5 — Port A bit 5 (bidirectional I/O) |
| Pin 8 | RE0/RD — Port E bit 0 / parallel slave port read |
| Pin 9 | RE1/WR — Port E bit 1 / parallel slave port write |
| Pin 10 | RE2/CS — Port E bit 2 / parallel slave port chip select |
| Pin 11 | VDD — Positive supply voltage (+5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC2/CLKOUT — Oscillator output / clock output |
| Pin 14 | RC0 — Port C bit 0 (bidirectional I/O) |
| Pin 15 | RC1 — Port C bit 1 (bidirectional I/O) |
| Pin 16 | RC2 — Port C bit 2 (bidirectional I/O) |
| Pin 17 | RC3 — Port C bit 3 (bidirectional I/O) |
| Pin 18 | RD0 — Port D bit 0 (bidirectional I/O) |
| Pin 19 | RD1 — Port D bit 1 (bidirectional I/O) |
| Pin 20 | RD2 — Port D bit 2 (bidirectional I/O) |
| Pin 21 | RD3 — Port D bit 3 (bidirectional I/O) |
| Pin 22 | RC4 — Port C bit 4 (bidirectional I/O) |
| Pin 23 | RC5 — Port C bit 5 (bidirectional I/O) |
| Pin 24 | RC6 — Port C bit 6 (bidirectional I/O) |
| Pin 25 | RC7 — Port C bit 7 (bidirectional I/O) |
| Pin 26 | RB0/INT — Port B bit 0 / external interrupt |
| Pin 27 | RB1 — Port B bit 1 (bidirectional I/O) |
| Pin 28 | RB2 — Port B bit 2 (bidirectional I/O) |
| Pin 29 | RB3 — Port B bit 3 (bidirectional I/O) |
| Pin 30 | RB4 — Port B bit 4 (bidirectional I/O) |
| Pin 31 | RB5 — Port B bit 5 (bidirectional I/O) |
| Pin 32 | RB6 — Port B bit 6 (bidirectional I/O) |
| Pin 33 | RB7 — Port B bit 7 (bidirectional I/O) |
| Pin 34 | VSS — Ground reference |
| Pin 35 | VDD — Positive supply voltage (+5V) |
| Pin 36 | RD4 — Port D bit 4 (bidirectional I/O) |
| Pin 37 | RD5 — Port D bit 5 (bidirectional I/O) |
| Pin 38 | RD6 — Port D bit 6 (bidirectional I/O) |
| Pin 39 | RD7 — Port D bit 7 (bidirectional I/O) |
| Pin 40 | VSS — Ground reference |
| Pin 41 | VDD — Positive supply voltage (+5V) |
| Pin 42 | VSS — Ground reference |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | MCLR/VPP — Master clear reset / programming voltage input |
Typical Applications
PIC16C64AT-04/PT is suitable for 6 applications: Industrial Process Control, Automotive In-Cabin Modules, Sensor Interface and Signal Conditioning, Legacy Equipment Maintenance, Educational and Development Kits, Low-Power Battery-Operated Devices.
Industrial Process Control
The PIC16C64AT-04/PT's 33 digital I/O pins and 4 MIPS CPU fit mid-complexity industrial control tasks including relay driving, sensor multiplexing, and HMI panel scanning. Its Watchdog Timer with on-chip RC oscillator provides autonomous recovery from EMI-induced lockups in factory-floor electrical environments where motors and contactors inject transient noise. The analog comparator enables threshold detection of process variables without an external op-amp, reducing BOM cost in PLC-style I/O modules. The 4.0-6.0 V supply matches 5 V industrial backplanes and accepts unregulated 24 V bus power after a simple linear regulator stage. The 128-byte RAM and 3.5 KB OTP program memory accommodate ladder-logic-style state machines for machine builders maintaining legacy equipment.
Recommended
Automotive In-Cabin Modules
The PIC16C64AT-04/PT is well suited to low-speed automotive body-electronics modules such as seat controllers, mirror actuators, and HVAC blend-door positioning where its 33 I/O and 4 MIPS performance is more than adequate. The industrial -40 C to +85 C temperature rating covers most in-cabin thermal environments; for under-hood applications the PIC16C64A-04E/PT variant extends to +125 C. The OTP memory model provides security against unauthorized firmware readout - important for Tier-1 suppliers protecting OEM-specific calibration data. The synchronous serial port (SSP) supports SPI communication with sensor ASICs and EEPROM memory devices commonly used in body controllers. The Watchdog Timer prevents module lockup during cranking transients and load-dump events common in 12 V automotive electrical systems.
Recommended
Sensor Interface and Signal Conditioning
The PIC16C64AT-04/PT's analog comparator and 33 I/O make it an effective front-end controller for sensor arrays requiring periodic polling, threshold detection, and digital I/O expansion. The on-chip comparator monitors analog signals against an internal bandgap reference without external op-amps, while the SSP module interfaces with SPI-output sensors and EEPROM/FRAM memory devices for calibration storage. The 4 MHz CPU supports averaging algorithms at kHz sample rates typical of thermocouple, RTD, and strain-gauge signal chains. Industrial temperature rating and OTP-based code protection suit field-deployed instrumentation where firmware IP and tamper resistance matter. The part is widely used in legacy OEM sensor transmitters and flow meters where redesign qualification would be cost-prohibitive.
Recommended
Legacy Equipment Maintenance
PIC16C64AT-04/PT remains in active demand as a maintenance-of-stock part for legacy OEM equipment whose field-deployed fleet spans 10-20 years. Industrial users holding certified designs cannot easily migrate to flash-based MCUs without re-qualifying their products under ISO 9001 and customer-specific change-control processes. The PIC16C64A family shares the same instruction set as PIC16F877A in most cases, but pinout and SFR mapping differences require re-validation. Third-party independent distributors maintain traceable inventory for known-good units. Use this part to bridge production runs of legacy products where redesign is on the roadmap but qualification is multi-year.
Recommended
Educational and Development Kits
The PIC16C64AT-04/PT is featured in legacy Microchip development tools and university curricula that teach 8-bit MCU fundamentals using the PIC16C6X instruction set as a reference architecture. Its simple RISC pipeline, 35-instruction set, and Harvard architecture make it an ideal teaching vehicle. The OTP memory model illustrates one-time-programmable security concepts still relevant for ASIC bring-up and ASIC emulation platforms. The 44-pin TQFP-44 with 33 I/O exposes ample peripherals for student projects involving PWM, timer, comparator, and serial port experimentation. Many existing lab kits and reference designs from the late 1990s and early 2000s use this exact MPN, sustaining niche educational demand.
Recommended
Low-Power Battery-Operated Devices
The PIC16C64AT-04/PT's CMOS process and 5 V operating voltage suit battery-powered applications drawing under 10 mA active and microamps in sleep mode when properly configured. Its Watchdog Timer can wake the device from sleep at programmed intervals, eliminating continuous CPU operation. The 33 I/O can drive low-side MOSFET switches for solenoid and motor control in portable equipment. The OTP memory prevents in-field firmware tampering for safety-critical applications such as medical devices and security hardware where the end user must not modify behavior. The 4 MHz CPU supports basic protocol stacks like 1-Wire and I2C bit-banging for sensor and memory peripherals.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C64AT-04/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C64A-04/PT | PIC16C64A-10/PT | PIC16C64A-20/PT | PIC16C64A-04E/PT | PIC16C64A-04I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin TQFP (PT) | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same |
| CPU Speed | 4 MHz | 4 MHz | 10 MHz | 20 MHz | 4 MHz | 4 MHz |
| Program Memory | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP | 3.5 KB OTP |
| RAM Size | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| Number of I/O | 33 | 33 | 33 | 33 | 33 | 33 |
| Supply Voltage | 4.0 V to 6.0 V | 4.0 V to 6.0 V | 4.0 V to 6.0 V | 4.5 V to 5.5 V | 4.0 V to 6.0 V | 4.0 V to 6.0 V |
| Operating Temperature | -40 C to +85 C | 0 C to +70 C | 0 C to +70 C | 0 C to +70 C | -40 C to +125 C | -40 C to +85 C |
| Packaging Form | Tape and Reel | Tray | Tray | Tray | Tray | Tray |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Identical silicon across the entire PIC16C64A family (vs PIC16C64A-04/PT)
- 33 I/O pins in a compact 44-pin TQFP (vs PIC16F877A-I/PT)
- Industrial temperature grade available on -04I suffix (vs PIC16C64A-04/PT (commercial 0C to +70C))
Design Notes
Decouple each VDD/VSS pair (there are four on the 44-pin TQFP) with a 100 nF ceramic capacitor placed within 5 mm of the IC pins. The multiple VDD pins are not internally bonded on the PIC16C64A silicon die - each must be externally powered for proper I/O driver operation. For battery applications, add a bulk 10 uF tantalum or aluminum polymer capacitor near the VDD pins to handle transient current demands during I/O switching.
The PIC16C64A silicon has documented anomalies in the Synchronous Serial Port (SSP) module per Microchip silicon errata - review device doc before designing SPI/I2C slave applications. In production programming, ensure MCLR/VPP rises to the proper VH level (typically 13V nominal) within the datasheet-specified rise time, otherwise OTP cells may program incorrectly. Use Microchip's approved programming algorithm only - third-party programmers may damage the EPROM cells.
For the 44-pin TQFP with 0.8 mm pitch, follow IPC-7351 land pattern guidelines: pad dimensions of 0.45 mm x 1.6 mm with a 0.4 mm pitch. Apply solder paste using a 0.15 mm thick stainless steel stencil with apertures reduced by 10-20% from the land pattern to prevent solder bridging on the fine-pitch leads. Place the crystal oscillator within 5 mm of OSC1 and OSC2 to minimize parasitic capacitance, and guard the traces with a ground ring to suppress EMI.
Route the MCLR/VPP trace away from high-noise signal lines and provide a dedicated test point for in-circuit programming access. If using an external reset supervisor, ensure the reset signal meets the minimum pulse width requirement (typically 2 instruction cycles minimum) to avoid incomplete resets. Route the OSC1/OSC2 traces symmetrically with matched lengths to maintain duty cycle accuracy on the internal clock.
Compliance Information
PIC16C64AT-04/PT is non-RoHS due to OTP EPROM process and lead-frame termination finish used at original release. The -04E and -04I suffix variants may have different compliance profiles - consult Microchip product environmental reports. Not AEC-Q100 qualified for automotive use despite industrial temperature grade.
