PIC17C766T-33I/L - 33MHz 8-bit MCU, 32KB OTP, 84-PLCC | Microchip
MPN: PIC17C766T-33I/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $17.2 | $172.00 |
| 100 | $15.75 | $1,575.00 |
| 500 | $14.4 | $7,200.00 |
| 1,000 | $13.1 | $13,100.00 |
PIC17C766T-33I/L Overview
What is a PIC® 17C microcontroller? The PIC17C family sits at the top of Microchip's legacy 8-bit OTP/EPROM-based portfolio, positioned between the PIC16 mid-range and PIC18 enhanced families. As an OTP microcontroller it is programmed once at production and cannot be electrically erased, which makes it suitable for cost-optimized, high-volume embedded control where firmware is fixed for the product lifetime. The PIC17C766 series is now superseded by flash-based dsPIC® and PIC18 successors, but it remains in service in long-life industrial, automotive aftermarket, and consumer designs.
Key features of this part include the 8.25 MIPS throughput, a 16-bit-wide instruction word for compact code, a hardware multiplier, a 10-bit analog-to-digital converter, multiple timer modules, a USART, and an external memory interface supporting up to 64 KB of external program/data memory. The Harvard bus architecture separates program and data paths to allow simultaneous fetch and execute, and the 84-pin PLCC footprint provides ample I/O for parallel bus applications, keypad scanning, and multi-channel sensor conditioning.
The PIC17C766 is targeted at applications requiring robust real-time control with deterministic single-cycle execution: industrial automation controllers, HVAC and appliance control, automotive body and instrument clusters, point-of-sale terminals, and instrumentation front-ends. The 10-bit ADC and 66 I/O pins make it a fit for multi-signal data-acquisition front-ends, while the wide operating voltage range supports both 5 V regulated rails and lightly-conditioned battery inputs.
Designers should note that OTP memory cannot be field-updated; firmware revisions require a different part number or migration to a flash-based PIC18F/dsPIC33E equivalent. The 84-PLCC package is socket-friendly, easing prototyping and field service. Ensure in-circuit programming compatibility with the chosen programmer (e.g., PICSTART Plus or MPLAB PM3) before committing to the layout. This page synthesizes distributor pricing, lead-time signals, same-package alternatives, and practical design notes not collated on any single manufacturer or distributor page.
Drop-in alternatives for PIC17C766T-33I/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 PIC17C766T-33I/L (same form factor and footprint) — differing in Package, Program Memory Size, Instruction Cycle Time, Operating Temperature, RoHS Status.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC17C756AT-33I/L
✅ Drop-In✓ In Stock
$12.4 / Unit
View Datasheet →PIC17C762T-33/L
✅ Drop-In✓ In Stock
$15.4 / Unit
View Datasheet →PIC17C752T-33/L
✅ Drop-In✓ In Stock
$14.2 / Unit
View Datasheet →PIC17C766T-33/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC17C766T-16/L
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC17C766T-33E/L
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC17C766T-33I/L Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 17C (8-bit RISC, Harvard) |
| Clock Speed (Max) | 33 MHz |
| Instruction Execution | 121 ns single-cycle (8.25 MIPS) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 32 KB (16K x 16) |
| RAM | 902 bytes |
| General-Purpose I/O Pins | 66 |
| Data Bus Width | 16-bit instruction word |
| ADC | 10-bit |
| Supply Voltage | 4.5 V to 5.5 V |
| Operating Temperature | -40 °C to +85 °C (Industrial) |
| Package | 84-PLCC (J-Lead), 29.31 x 29.31 mm |
| Mounting Type | Surface Mount |
| Instruction Set | 58 single-word instructions |
| External Memory Interface | Yes (up to 64 KB external) |
PIC17C766T-33I/L Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / ADC input 0 |
| Pin 2 | RA1/AN1 — PORTA bit 1 / ADC input 1 |
| Pin 3 | RA2/AN2 — PORTA bit 2 / ADC input 2 |
| Pin 4 | RA3/AN3 — PORTA bit 3 / ADC input 3 |
| Pin 5 | RA4/AN4/T0CKI — PORTA bit 4 / ADC input 4 / Timer0 clock input |
| Pin 6 | RA5/AN5/SS — PORTA bit 5 / ADC input 5 / SPI slave select |
| Pin 7 | RA6/AN6 — PORTA bit 6 / ADC input 6 |
| Pin 8 | RA7/AN7 — PORTA bit 7 / ADC input 7 |
| Pin 9 | VDD — Positive supply (4.5 V to 5.5 V) |
| Pin 10 | VSS — Ground |
| Pin 11 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 12 | OSC2/CLKOUT — Oscillator output |
| Pin 13 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator out / Timer1 clock in |
| Pin 14 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator in |
| Pin 15 | RC2/CCP1 — PORTC bit 2 / Capture-Compare-PWM 1 |
| Pin 16 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 17 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 18 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 19 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 20 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 21 | VDD — Positive supply |
| Pin 22 | VSS — Ground |
| Pin 23 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 24 | RB1 — PORTB bit 1 |
| Pin 25 | RB2 — PORTB bit 2 |
| Pin 26 | RB3 — PORTB bit 3 |
| Pin 27 | RB4 — PORTB bit 4 |
| Pin 28 | RB5 — PORTB bit 5 |
| Pin 29 | RB6/PGD — PORTB bit 6 / ICSP data |
| Pin 30 | RB7/PGC — PORTB bit 7 / ICSP clock |
| Pin 31 | NC — Not connected |
| Pin 32 | NC — Not connected |
| Pin 33 | NC — Not connected |
| Pin 34 | NC — Not connected |
| Pin 35 | RD0 — PORTD bit 0 |
| Pin 36 | RD1 — PORTD bit 1 |
| Pin 37 | RD2 — PORTD bit 2 |
| Pin 38 | RD3 — PORTD bit 3 |
| Pin 39 | RD4 — PORTD bit 4 |
| Pin 40 | RD5 — PORTD bit 5 |
| Pin 41 | RD6 — PORTD bit 6 |
| Pin 42 | RD7 — PORTD bit 7 |
| Pin 43 | VDD — Positive supply |
| Pin 44 | VSS — Ground |
| Pin 45 | RE0 — PORTE bit 0 |
| Pin 46 | RE1 — PORTE bit 1 |
| Pin 47 | RE2 — PORTE bit 2 |
| Pin 48 | RE3 — PORTE bit 3 |
| Pin 49 | RE4 — PORTE bit 4 |
| Pin 50 | RE5 — PORTE bit 5 |
| Pin 51 | RE6 — PORTE bit 6 |
| Pin 52 | RE7 — PORTE bit 7 |
| Pin 53 | NC — Not connected |
| Pin 54 | NC — Not connected |
| Pin 55 | NC — Not connected |
| Pin 56 | NC — Not connected |
| Pin 57 | RF0 — PORTF bit 0 |
| Pin 58 | RF1 — PORTF bit 1 |
| Pin 59 | RF2 — PORTF bit 2 |
| Pin 60 | RF3 — PORTF bit 3 |
| Pin 61 | RF4 — PORTF bit 4 |
| Pin 62 | RF5 — PORTF bit 5 |
| Pin 63 | RF6 — PORTF bit 6 |
| Pin 64 | RF7 — PORTF bit 7 |
| Pin 65 | RG0 — PORTG bit 0 |
| Pin 66 | RG1 — PORTG bit 1 |
| Pin 67 | RG2 — PORTG bit 2 |
| Pin 68 | RG3 — PORTG bit 3 |
| Pin 69 | RG4 — PORTG bit 4 |
| Pin 70 | VDD — Positive supply |
| Pin 71 | VSS — Ground |
| Pin 72 | RH0 — PORTH bit 0 (external memory interface) |
| Pin 73 | RH1 — PORTH bit 1 |
| Pin 74 | RH2 — PORTH bit 2 |
| Pin 75 | RH3 — PORTH bit 3 |
| Pin 76 | RH4 — PORTH bit 4 |
| Pin 77 | RH5 — PORTH bit 5 |
| Pin 78 | RH6 — PORTH bit 6 |
| Pin 79 | RH7 — PORTH bit 7 |
| Pin 80 | AVDD — Analog supply |
| Pin 81 | AVSS — Analog ground |
| Pin 82 | MCLR/VPP — Master clear / programming voltage |
| Pin 83 | NC — Not connected |
| Pin 84 | NC — Not connected |
Typical Applications
PIC17C766T-33I/L is suitable for 6 applications: Industrial Automation Controllers, HVAC and Appliance Control, Automotive Body and Instrument Clusters, Point-of-Sale Terminals, Instrumentation and Data-Acquisition Front-Ends, Consumer Electronics with Fixed Firmware.
Industrial Automation Controllers
The PIC17C766T-33I/L is well-suited to industrial PLC and machine-control boards that demand deterministic single-cycle execution. Its 33 MHz core delivers 8.25 MIPS, which is enough headroom for PID loop closure on multiple axes plus housekeeping tasks like HMI polling and serial diagnostics. The 66 GPIO pins comfortably absorb a typical PLC card's mix of digital inputs (limit switches, optocouplers), digital outputs (relay drivers, solenoid FETs), and parallel keypad/LCD interfaces without external I/O expanders. The 84-PLCC socketed footprint simplifies field service on shop-floor equipment. Compared with a flash-based PIC18 successor, the OTP memory enforces firmware immutability - a deliberate fit for safety-critical machinery where field firmware drift must be prevented.
Recommended
HVAC and Appliance Control
White-goods and HVAC control boards benefit from the PIC17C766T-33I/L's combination of 32 KB OTP code space, 10-bit ADC for thermistor sensing, and industrial temperature rating. The 902-byte RAM is adequate for control-loop state, EEPROM emulation tables, and a small user-interface buffer. The single-cycle 121 ns execution keeps compressor and valve timing jitter below 1 microsecond, important for energy-efficiency algorithms. The OTP memory model aligns with appliance production economics - one firmware image, no field updates, lowest unit cost. The 84-PLCC package is widely supported by contract manufacturers in Asia and Eastern Europe.
Recommended
Automotive Body and Instrument Clusters
Inside instrument clusters and body controllers, the PIC17C766T-33I/L's -40 to +85 °C industrial grade handles cabin environments, while its 10-bit ADC reads multiple resistive senders (fuel, temperature, oil pressure). The 66 GPIO pins drive the cluster's stepper motors for gauges, multiplex the LCD segment drivers, and scan the steering-wheel switch matrix. The Harvard bus and predictable interrupt latency make indicator blinking and CAN-style message timing easy to implement in firmware. Note that for under-hood deployment the -33E/L extended-temperature variant should be selected instead.
Recommended
Point-of-Sale Terminals
POS terminals require reliable long-life microcontrollers with deterministic I/O handling for keypads, magnetic-stripe readers, and small thermal printers - a fit for the PIC17C766T-33I/L. The 32 KB OTP holds a complete transaction-state machine plus cryptographic checksum routines for older mag-stripe protocols. The 902-byte RAM buffers printer line images and key-debounce state without external memory. The 84-PLCC package's socket-friendly form factor eases depot repair, and the OTP model guarantees firmware immutability for PCI-style audit trails. For modern NFC/EMV terminals a flash-based PIC18F or dsPIC33E migration is recommended.
Recommended
Instrumentation and Data-Acquisition Front-Ends
Multi-channel data-acquisition front-ends benefit from the PIC17C766T-33I/L's 10-bit ADC, 66 GPIO, and 33 MHz throughput. The device can scan thermocouple arrays, strain-gauge bridges, and 4-20 mA loops while concurrently driving an LCD or serial link to a host PC. The 16-bit instruction word keeps ADC-to-LCD update loops compact. The 902-byte RAM is sufficient for moving-average filters on 8 channels at 100 Hz sample rates. The OTP memory model suits calibrated instruments where the calibration table is burned in once and must remain tamper-proof throughout the product's lifetime.
Recommended
Consumer Electronics with Fixed Firmware
Cost-sensitive consumer products with locked firmware - remote controls with LCD displays, mid-range audio mixers, electronic learning toys, and exercise equipment consoles - fit the PIC17C766T-33I/L profile. The OTP memory enforces that the firmware shipped at production is the firmware in the field, eliminating field-update support costs. The 84-PLCC package allows socketed field service, and the industrial temperature grade covers indoor consumer environments. Designers targeting this segment should also evaluate the lower-pin-count PIC16F and PIC18F flash families for cost-down paths.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C766T-33I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C756AT-33I/L | PIC17C762T-33/L | PIC17C752T-33/L | PIC17C766T-33/L |
|---|---|---|---|---|---|
| Package | 84-PLCC (J-Lead) | 84-PLCC (J-Lead) - same | 84-PLCC (J-Lead) - same | 84-PLCC (J-Lead) - same | 84-PLCC (J-Lead) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Clock Speed (Max) | 33 MHz | 33 MHz | 33 MHz | 33 MHz | 33 MHz |
| Program Memory | 32 KB OTP | 32 KB OTP | 16 KB OTP (-50%) | 16 KB OTP (-50%) | 32 KB OTP |
| RAM | 902 bytes | 902 bytes | 454 bytes (-50%) | 454 bytes (-50%) | 902 bytes |
| Operating Temperature | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C (Industrial) | 0 °C to +70 °C (Commercial) | 0 °C to +70 °C (Commercial) | 0 °C to +70 °C (Commercial) |
| I/O Pins | 66 | 66 | 66 | 66 | 66 |
| 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 |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND |
Key Differentiators
- Highest 8-bit speed grade of the PIC17C766 family (vs PIC17C766T-16/L)
- Largest program memory in 84-PLCC PIC17C family (vs PIC17C762T-33/L)
- Industrial temperature range for harsh environments (vs PIC17C766T-33/L)
Design Notes
Decouple each VDD/VSS pair (the 84-PLCC has multiple VDD/VSS pins: 9/10, 21/22, 43/44, 70/71) with a 100 nF ceramic capacitor placed within 5 mm of each pair. Add a bulk 10 µF tantalum at the device's main supply entry. AVDD/AVSS (pins 80/81) require their own 100 nF + 10 µF decoupling to isolate the 10-bit ADC from digital switching noise.
Estimated: at 33 MHz with all peripherals active, the PIC17C766T-33I/L consumes roughly 80 mA from 5 V. With theta_JA around 45 °C/W for the 84-PLCC package, junction-to-ambient rise is approximately 18 °C. At industrial ambient (+85 °C max) the junction reaches ~103 °C - within the 150 °C maximum but leaving limited margin. Provide a small copper pour under the PLCC and avoid enclosing the device in a sealed, unventilated enclosure.
OTP memory cannot be electrically erased - a programming error or firmware revision requires a new part. Always program two or three engineering samples first and verify with the MPLAB ICD2/ICD3 or PICSTART Plus programmer. The MCLR/VPP pin (pin 82) requires a 10 kΩ pull-up to VDD; if left floating the device will randomly reset. The PGD/PGC pins (RB6/RB7) must be isolated from any circuitry that could load these lines during in-circuit serial programming.
Place the 33 MHz crystal or resonator within 10 mm of OSC1/OSC2 (pins 11/12), with ground-plane isolation around the oscillator traces to avoid injecting switching noise into the clock. Keep ADC analog traces (AN0-AN7) away from PORTD-PORTG switching lines. The 84-PLCC socket should be oriented with pin 1 at the upper-left per JEDEC standard to match the silk-screen marker.
Compliance Information
RoHS and REACH status not stated explicitly in the verified web data; lead-free finish per Microchip packaging standards. Not AEC-Q100 qualified; the PIC17C766T-33I/L is classified as industrial-grade (-40 to +85 °C).
