PIC17C766-16I/L - 8-Bit 16MHz OTP MCU, 32KB, 84-PLCC | Microchip
MPN: PIC17C766-16I/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.85 | $12.85 |
| 10 | $11.78 | $117.80 |
| 100 | $10.42 | $1,042.00 |
| 500 | $9.15 | $4,575.00 |
| 1,000 | $8.2 | $8,200.00 |
PIC17C766-16I/L Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (ROM/Flash/OTP), data memory (RAM), and programmable I/O peripherals. The 8-bit MCU class predates 16-bit and 32-bit Cortex-M parts and remains widely deployed in cost-sensitive, deterministic control applications. Within Microchip's portfolio, the PIC17C family sits between the PIC16 mid-range and the enhanced PIC18 devices, offering more peripherals and code space than PIC16 while remaining upward-compatible with PIC12Cxxx and PIC16Cxx instruction sets - only 58 single-word instructions to learn, with all instructions executing in a single cycle except program branches and table reads/writes, which take two cycles.
Key differentiating features of the PIC17C766 include its 84-pin PLCC footprint supporting 66 I/O lines, the integrated 10-bit ADC, hardware multiplier for fast DSP-style math, and the 32 KB (16K x 16) OTP program memory that is one-time programmable but production-friendly. The 16 MHz oscillator with 4-clock internal divider yields the 121 ns instruction cycle, and the device supports a wide peripheral set including USART, capture/compare/PWM, and timers suitable for motor and power conversion control.
Architecturally, the PIC17C766 uses a Harvard bus (separate program and data paths) and an enhanced 8-bit core with a hardware multiply engine; combined with the OTP memory it is well suited to volume production where firmware is fixed at the time of manufacture. Per the manufacturer datasheet, the PIC17C766 is the largest-memory member of the PIC17C family and is now designated NRND/EOL with the PIC18F8520 recommended as the modern flash-based successor.
Typical applications include industrial motor control, HVAC actuators, automotive body and chassis subsystems, white goods and appliance control, and embedded control boards that need many parallel I/O lines plus on-chip ADC. The 84-pin PLCC package is also attractive for legacy through-hole designs and socketed prototyping. When designing with this part, plan for OTP-only programming (code must be committed at production time) and verify supply availability since the device is being phased out in favor of PIC18F flash parts.
Drop-in alternatives for PIC17C766-16I/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 PIC17C766-16I/L (same form factor and footprint) — differing in Package, Core Architecture, Mounting Type, Operating Temperature, Data Bus Width.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC17C766-16I/PT
✅ Drop-In✓ In Stock
$11.5 / Unit
View Datasheet →PIC17C766-16E/PT
✅ Drop-In✓ In Stock
$9.95 / Unit
View Datasheet →PIC17C756A-16I/PT
✅ Drop-In✓ In Stock
$11.2 / Unit
View Datasheet →PIC17C762-16I/PT
✅ Drop-In✓ In Stock
$10.05 / Unit
View Datasheet →PIC17C762-16/PT
✅ Drop-In✓ In Stock
$9.25 / Unit
View Datasheet →PIC17C766-16I/L Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit (Harvard, RISC) |
| Instruction Set | 58 single-word instructions (PIC17C enhanced) |
| Data Bus Width | 8-bit |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 32 KB (16K x 16) |
| RAM Size | 902 bytes |
| Maximum Clock Frequency | 16 MHz |
| Instruction Cycle Time | 121 ns (8.25 MIPS) |
| Supply Voltage (Vdd) | 4.5 V to 5.5 V |
| I/O Pins | 66 |
| ADC | 10-bit, multi-channel |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 84-pin PLCC (LCC-84 / QCCJ) |
| Mounting Type | Surface Mount / Socketed |
| Lead Finish / Terminal Form | J-bend (PLCC) |
| Recommended Successor | PIC18F8520 |
PIC17C766-16I/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 — PORTA bit 3 / analog input 3 |
| Pin 6 | RA4/AN4 — PORTA bit 4 / analog input 4 |
| Pin 7 | RA5/AN5 — PORTA bit 5 / analog input 5 |
| Pin 8 | RA6/AN6 — PORTA bit 6 / analog input 6 |
| Pin 9 | RA7/AN7 — PORTA bit 7 / analog input 7 |
| Pin 10 | Vss — Ground |
| Pin 11 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 12 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 13 | RC0 — PORTC bit 0 |
| Pin 14 | RC1 — PORTC bit 1 |
| Pin 15 | RC2 — PORTC bit 2 |
| Pin 16 | RC3 — PORTC bit 3 |
| Pin 17 | RD0 — PORTD bit 0 |
| Pin 18 | RD1 — PORTD bit 1 |
| Pin 19 | RD2 — PORTD bit 2 |
| Pin 20 | RD3 — PORTD bit 3 |
| Pin 21 | RD4 — PORTD bit 4 |
| Pin 22 | RD5 — PORTD bit 5 |
| Pin 23 | RD6 — PORTD bit 6 |
| Pin 24 | RD7 — PORTD bit 7 |
| Pin 25 | Vss — Ground |
| Pin 26 | Vdd — Positive supply (4.5 V to 5.5 V) |
| Pin 27 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 28 | RB1 — PORTB bit 1 |
| Pin 29 | RB2 — PORTB bit 2 |
| Pin 30 | RB3 — PORTB bit 3 |
| Pin 31 | RB4 — PORTB bit 4 |
| Pin 32 | RB5 — PORTB bit 5 |
| Pin 33 | RB6 — PORTB bit 6 |
| Pin 34 | RB7 — PORTB bit 7 |
| Pin 35 | RC4 — PORTC bit 4 |
| Pin 36 | RC5 — PORTC bit 5 |
| Pin 37 | RC6 — PORTC bit 6 |
| Pin 38 | RC7 — PORTC bit 7 |
| Pin 39 | RE0 — PORTE bit 0 |
| Pin 40 | RE1 — PORTE bit 1 |
| Pin 41 | RE2 — PORTE bit 2 |
| Pin 42 | RE3 — PORTE bit 3 |
| Pin 43 | RE4 — PORTE bit 4 |
| Pin 44 | RE5 — PORTE bit 5 |
| Pin 45 | RE6 — PORTE bit 6 |
| Pin 46 | RE7 — PORTE bit 7 |
| Pin 47 | Vss — Ground |
| Pin 48 | Vdd — Positive supply |
| Pin 49 | RF0 — PORTF bit 0 |
| Pin 50 | RF1 — PORTF bit 1 |
| Pin 51 | RF2 — PORTF bit 2 |
| Pin 52 | RF3 — PORTF bit 3 |
| Pin 53 | RF4 — PORTF bit 4 |
| Pin 54 | RF5 — PORTF bit 5 |
| Pin 55 | RF6 — PORTF bit 6 |
| Pin 56 | RF7 — PORTF bit 7 |
| Pin 57 | RG0 — PORTG bit 0 |
| Pin 58 | RG1 — PORTG bit 1 |
| Pin 59 | RG2 — PORTG bit 2 |
| Pin 60 | RG3 — PORTG bit 3 |
| Pin 61 | RG4 — PORTG bit 4 |
| Pin 62 | RG5 — PORTG bit 5 |
| Pin 63 | RG6 — PORTG bit 6 |
| Pin 64 | RG7 — PORTG bit 7 |
| Pin 65 | AVdd — Analog supply voltage |
| Pin 66 | AVss — Analog ground |
| Pin 67 | RH0 — PORTH bit 0 |
| Pin 68 | RH1 — PORTH bit 1 |
| Pin 69 | RH2 — PORTH bit 2 |
| Pin 70 | RH3 — PORTH bit 3 |
| Pin 71 | RH4 — PORTH bit 4 |
| Pin 72 | RH5 — PORTH bit 5 |
| Pin 73 | RH6 — PORTH bit 6 |
| Pin 74 | RH7 — PORTH bit 7 |
| Pin 75 | Vss — Ground |
| Pin 76 | Vdd — Positive supply |
| Pin 77 | TOCK1 — Timer0 clock input |
| Pin 78 | NC — Not connected (per datasheet) |
| Pin 79 | NC — Not connected (per datasheet) |
| Pin 80 | NC — Not connected (per datasheet) |
| Pin 81 | NC — Not connected (per datasheet) |
| Pin 82 | NC — Not connected (per datasheet) |
| Pin 83 | NC — Not connected (per datasheet) |
| Pin 84 | NC — Not connected (per datasheet) |
Typical Applications
PIC17C766-16I/L is suitable for 6 applications: Industrial Motor Control, HVAC and Building Automation, White Goods and Appliance Control, Automotive Body and Chassis Modules, Embedded Instrumentation, Point-of-Sale and Embedded Terminals.
Industrial Motor Control
The PIC17C766-16I/L fits industrial motor-control designs that demand many I/O lines, fast deterministic interrupts, and integrated ADC feedback. With 66 I/O, a 10-bit ADC, hardware PWM/capture modules, and 8.25 MIPS throughput at 16 MHz, it can drive 3-phase inverter commutation, BLDC trapezoidal commutation, or stepper sequencing while sampling current and back-EMF. The 84-pin PLCC also accepts through-hole sockets, easing prototype rework on legacy drives. Note the OTP-only program memory - firmware is committed at production and cannot be field-updated, so use the PIC18F8520 successor if field updates are required.
Recommended
HVAC and Building Automation
HVAC controllers need deterministic timing, plentiful I/O for sensor arrays and triac drivers, and on-chip ADC for temperature and pressure sensing - all native strengths of the PIC17C766-16I/L. The 32 KB OTP (16K x 16) holds complex thermostat, damper, and VAV control loops, while 66 I/O lines multiplex keypads, displays, relay banks and serial communication. The 84-pin PLCC package simplifies socket-based prototyping during NPI builds. Industrial temperature rating (-40 C to +85 C) suits unconditioned equipment rooms, and the 121 ns interrupt latency keeps control loops stable.
Recommended
White Goods and Appliance Control
Washing machines, dishwashers, ovens and refrigerators rely on a single MCU managing motor, valve, sensor, and user-interface functions - exactly the workload the PIC17C766-16I/L was designed for. The integrated 10-bit ADC digitizes temperature and water-level sensors, while 66 I/O lines drive triac-controlled heater elements, latching valves, and multiplexed key/display panels. The OTP memory locks firmware at production, preventing tampering and ensuring regulatory consistency. The PLCC-84 socket compatibility simplifies factory programming and field service swaps. Plan for an NRE mask change if any code update is required after launch.
Recommended
Automotive Body and Chassis Modules
Body controllers for door modules, seat controllers, instrument clusters, and lighting drivers often pair a microcontroller with discrete drivers. The PIC17C766-16I/L's 66 I/O lines, hardware PWM, and 10-bit ADC cover LIN/analog sensing and MOSFET/relay drive in one chip. The 84-pin PLCC package and 5 V supply suit pre-CAN-bus modules still in production for trucks and off-highway vehicles. Note the Industrial (-40 C to +85 C) rather than AEC-Q100 grade; for new automotive designs use dsPIC33 or PIC18F-Q1 parts instead. Useful for service replacements of legacy modules.
Recommended
Embedded Instrumentation
Bench instruments, data loggers, and process-control front-ends benefit from the PIC17C766-16I/L's 66 I/O for keypad and LCD interfaces, the 10-bit ADC for sensor conditioning, and the 32 KB OTP (16K x 16) for calibration tables and menu state machines. The 8.25 MIPS throughput is enough to drive simple text UIs and serial protocols such as RS-232/RS-485 via the on-chip USART. The 84-pin PLCC package is a legacy-friendly choice for through-hole or socketed repair of installed equipment. For new designs requiring field upgradeability, migrate to PIC18F or dsPIC33EP families.
Recommended
Point-of-Sale and Embedded Terminals
POS terminals, vending machine controllers, and ticket dispensers need reliable fixed-function control with many I/O for keypads, displays, and serial peripherals. The PIC17C766-16I/L delivers 66 I/O lines, an integrated 10-bit ADC, USART, and 8.25 MIPS throughput to manage keypad scanning, LCD multiplex, currency sensing, and serial audit logs. The 32 KB OTP locks firmware at production to prevent field tampering - a useful property for metered equipment. The PLCC-84 socket footprint simplifies depot-level repair. Pair with external EEPROM for audit-trail storage and add a watchdog supervisor for unattended deployment.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C766-16I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C766-16I/PT | PIC17C766-16E/PT | PIC17C756A-16I/PT | PIC17C762-16I/PT | PIC17C762-16/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 84-pin PLCC (LCC-84) | 84-pin TQFP | 84-pin TQFP | 84-pin TQFP | 84-pin TQFP | 84-pin TQFP |
| Program Memory | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP |
| RAM | 902 B | 902 B | 902 B | 902 B | 902 B | 902 B |
| Max Clock | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| MIPS | 8.25 MIPS | 8.25 MIPS | 8.25 MIPS | 8.25 MIPS | 8.25 MIPS | 8.25 MIPS |
| I/O Pins | 66 | 66 | 66 | 66 | 66 | 66 |
| Temperature Grade | Industrial -40C to +85C | Industrial -40C to +85C | Extended -40C to +125C | Industrial -40C to +85C | Industrial -40C to +85C | Commercial 0C to +70C |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
| Lifecycle | NRND | NRND | NRND | EOL | EOL | EOL |
Key Differentiators
- Largest memory in the PIC17C family with 84-pin PLCC and 66 I/O (vs PIC17C762-16I/PT)
- Industrial -40 C to +85 C grade in socket-friendly PLCC package (vs PIC17C766-16I/PT)
- Mature 8-bit PIC17C core with 58 single-word instructions (vs PIC18F8520)
Design Notes
PIC17C766-16I/L uses OTP EPROM - firmware can only be programmed once, so commit code only after firmware is fully validated. A programming-cycle mistake costs the entire part. Always order engineering samples or use a PIC18F8520 (flash) for firmware development, then port the final image to the PIC17C766 for production.
Power the PIC17C766-16I/L from a regulated 4.5 V to 5.5 V supply with a 100 nF decoupling cap within 5 mm of each Vdd/Vss pair (there are 4 pairs on the 84-pin PLCC). Place a bulk 10 uF tantalum plus 100 nF ceramic on the analog AVdd/AVss pair and route AVss to a clean ground island. Add a watchdog supervisor and a manual reset button tied to MCLR through a 10 kohm pull-up for robust industrial bring-up.
The 84-pin PLCC is a J-lead surface-mount package that also fits standard PLCC sockets - useful for prototype rework and field replacement. Maintain 0.5 mm clearance under the package to allow cleaning; route oscillator traces (OSC1/OSC2) short and guard them with a ground trace to minimize EMI. Avoid routing switching signals near AVdd/AVss, and keep the analog reference pins (Vref+/Vref-) short and bypassed with 100 nF.
OSC1/OSC2 traces should be kept under 10 mm with a ground guard on both sides to avoid radiating clock harmonics into ADC inputs. The 10-bit ADC reaches ~ +/-1 LSB accuracy only if the analog supply is well decoupled and digital traces do not cross analog traces - use a ground moat around the analog pins. The 121 ns instruction cycle allows deterministic ADC sampling, but enable the ADC acquisition delay based on source impedance to avoid conversion errors.
Compliance Information
RoHS, REACH, lead-free and halogen-free status for PIC17C766-16I/L were not explicitly stated in the distributor data provided. Industrial temperature grade (-40C to +85C) is confirmed but AEC-Q100 automotive qualification is not - for new automotive designs use PIC18F-Q1 or dsPIC33EV-Q1 parts.
