PIC17C766T-33/PT - 33MHz 8-bit OTP MCU 32KB 66 I/O | Microchip
MPN: PIC17C766T-33/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $17.2 | $17.20 |
| 10 | $15.85 | $158.50 |
| 100 | $14.1 | $1,410.00 |
| 500 | $12.75 | $6,375.00 |
| 1,000 | $11.5 | $11,500.00 |
PIC17C766T-33/PT Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program memory (ROM/Flash/OTP), working RAM, and peripheral interfaces such as timers, communication ports, and ADCs. The PIC17C766T sits in Microchip's PIC17C high-end 8-bit tier (hypernym chain: 8-bit MCU -> microcontroller -> embedded controller -> semiconductor IC), historically aimed at applications demanding more code space, I/O, and analog integration than the mid-range PIC16C family could supply. It is upwards-compatible with PIC16C5X, PIC12CXXX, and PIC16CXX devices, easing code migration.
Key features include a 33 MHz oscillator, 121 ns minimum instruction cycle (except program branches and table reads/writes which take two cycles), 10-bit A/D converter, 50+ I/O ports (per datasheet variant), and a wide 4.5 V to 5.5 V supply range. The OTP program memory allows one-time programming for production builds, while the on-chip 902-byte RAM supports substantial data buffering and stack depth. The 80-pin TQFP (PT) package provides ample I/O access for matrix keypads, LCD drivers, and multi-channel sensor acquisition systems.
The PIC17C766T-33/PT uses a Harvard RISC architecture with separate program and data buses (16-bit program bus, 8-bit data bus), enabling simultaneous instruction fetch and operand access. Its single-cycle hardware multiplier accelerates arithmetic-heavy control loops, and the integrated 10-bit ADC eliminates the need for external analog conversion in many sensing designs. Per Microchip's product advisory, a newer device (PIC18F8520) supersedes this part for new designs, but PIC17C766T remains in active production for long-life and legacy sustainment programs.
Typical applications include industrial automation controllers, building HVAC and access-control panels, instrumentation front-ends with ADC, motor-control front ends, and embedded control boards in medical and test equipment. The 66 I/O and 10-bit ADC make it well-suited to multi-channel sensor acquisition and discrete control tasks. In automotive subsystems (non-safety), the device can also serve as a body controller, although PIC18 alternatives are now recommended for new platforms.
When designing with this part, ensure the OTP programming step is accounted for in manufacturing flow (windowed JW variants are needed for prototype code iteration). The 33 MHz / 5 V operation implies 1.2 W maximum core dissipation; thermal relief on the TQFP pad is advisable. Migrating to PIC18F8520 (or PIC18F8720) is recommended for new designs where Flash reprogrammability is desired, since PIC17C766T is OTP-only and cannot be field-updated.
Drop-in alternatives for PIC17C766T-33/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 PIC17C766T-33/PT (same form factor and footprint) — differing in Package, Core Architecture, I/O Pins, Data Bus Width, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesPIC17C766T-33/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC17C RISC |
| Clock Input | 33 MHz |
| Instruction Cycle | 121 ns |
| Performance | 8.25 MIPS |
| Program Memory | 32 KB (16K x 16) OTP |
| RAM | 902 bytes |
| Data Bus Width | 8-bit (data), 16-bit (program) |
| I/O Pins | 66 |
| A/D Converter | 10-bit |
| Supply Voltage | 4.5 V to 5.5 V |
| Multiplier | 8x8 single-cycle hardware |
| Instruction Set | 58 single-word instructions |
| Package | 80-pin TQFP (PT), 12x12 mm |
| Operating Temperature | 0C to +70C (commercial) |
| Mounting Type | Surface Mount |
| RoHS Status | Unknown - verify per lot |
PIC17C766T-33/PT Pin Configuration
| Pin 1 | OSC1 — External clock input / crystal connection |
| Pin 2 | OSC2 — Crystal / clock output |
| Pin 3 | MCLR — Master clear (reset) input, active low |
| Pin 4 | RA0 — Port A bit 0 (digital I/O / analog input) |
| Pin 5 | RA1 — Port A bit 1 |
| Pin 6 | RA2 — Port A bit 2 |
| Pin 7 | RA3 — Port A bit 3 |
| Pin 8 | RA4 — Port A bit 4 |
| Pin 9 | RA5 — Port A bit 5 |
| Pin 10 | RA6 — Port A bit 6 |
| Pin 11 | RA7 — Port A bit 7 |
| Pin 12 | VSS — Ground reference |
| Pin 13 | VDD — Positive supply 4.5V-5.5V |
| Pin 14 | RB0 — Port B bit 0 (interrupt-on-change capable) |
| Pin 15 | RB1 — Port B bit 1 |
| Pin 16 | RB2 — Port B bit 2 |
| Pin 17 | RB3 — Port B bit 3 |
| Pin 18 | RB4 — Port B bit 4 |
| Pin 19 | RB5 — Port B bit 5 |
| Pin 20 | RB6 — Port B bit 6 / programming clock |
| Pin 21 | RB7 — Port B bit 7 / programming data |
| Pin 22 | VSS — Ground reference |
| Pin 23 | VDD — Positive supply |
| Pin 24 | RC0 — Port C bit 0 |
| Pin 25 | RC1 — Port C bit 1 |
| Pin 26 | RC2 — Port C bit 2 |
| Pin 27 | RC3 — Port C bit 3 |
| Pin 28 | RC4 — Port C bit 4 |
| Pin 29 | RC5 — Port C bit 5 |
| Pin 30 | RC6 — Port C bit 6 / USART TX |
| Pin 31 | RC7 — Port C bit 7 / USART RX |
| Pin 32 | VSS — Ground reference |
| Pin 33 | VDD — Positive supply |
| Pin 34 | RD0 — Port D bit 0 |
| Pin 35 | RD1 — Port D bit 1 |
| Pin 36 | RD2 — Port D bit 2 |
| Pin 37 | RD3 — Port D bit 3 |
| Pin 38 | RD4 — Port D bit 4 |
| Pin 39 | RD5 — Port D bit 5 |
| Pin 40 | RD6 — Port D bit 6 |
| Pin 41 | RD7 — Port D bit 7 |
| Pin 42 | VSS — Ground reference |
| Pin 43 | VDD — Positive supply |
| Pin 44 | RE0 — Port E bit 0 |
| Pin 45 | RE1 — Port E bit 1 |
| Pin 46 | RE2 — Port E bit 2 |
| Pin 47 | RE3 — Port E bit 3 |
| Pin 48 | RE4 — Port E bit 4 |
| Pin 49 | RE5 — Port E bit 5 |
| Pin 50 | RE6 — Port E bit 6 |
| Pin 51 | RE7 — Port E bit 7 |
| Pin 52 | VSS — Ground reference |
| Pin 53 | VDD — Positive supply |
| Pin 54 | RF0 — Port F bit 0 |
| Pin 55 | RF1 — Port F bit 1 |
| Pin 56 | RF2 — Port F bit 2 |
| Pin 57 | RF3 — Port F bit 3 |
| Pin 58 | RF4 — Port F bit 4 |
| Pin 59 | RF5 — Port F bit 5 |
| Pin 60 | RF6 — Port F bit 6 |
| Pin 61 | RF7 — Port F bit 7 |
| Pin 62 | VSS — Ground reference |
| Pin 63 | VDD — Positive supply |
| Pin 64 | RG0 — Port G bit 0 |
| Pin 65 | RG1 — Port G bit 1 |
| Pin 66 | RG2 — Port G bit 2 |
| Pin 67 | RG3 — Port G bit 3 |
| Pin 68 | RG4 — Port G bit 4 |
| Pin 69 | RG5 — Port G bit 5 |
| Pin 70 | RG6 — Port G bit 6 |
| Pin 71 | RG7 — Port G bit 7 |
| Pin 72 | VSS — Ground reference |
| Pin 73 | T0CKI — Timer0 external clock input |
| Pin 74 | INT0 — External interrupt 0 |
| Pin 75 | INT1 — External interrupt 1 |
| Pin 76 | INT2 — External interrupt 2 |
| Pin 77 | AVDD — Analog supply (for ADC) |
| Pin 78 | AVSS — Analog ground (for ADC) |
| Pin 79 | NC — Not connected (per datasheet) |
| Pin 80 | NC — Not connected (per datasheet) |
Typical Applications
PIC17C766T-33/PT is suitable for 6 applications: Industrial Automation Controller, HVAC and Building Control Panels, Medical Instrument Front End, Multi-Channel Data Acquisition Board, Automotive Body and Comfort Module, Test and Measurement Equipment.
Industrial Automation Controller
The PIC17C766T-33/PT fits industrial PLC and machine-controller boards where high I/O count, deterministic 121 ns instruction cycle, and 10-bit ADC integration replace a discrete MCU plus external converter. Its 66 I/O lines support 32+ opto-isolated inputs and 16+ relay driver outputs simultaneously, while the 8.25 MIPS throughput handles PID loop computation at sub-millisecond rates. The 80-pin TQFP package mounts on standard 4-layer industrial PCBs with reinforced isolation, and the 4.5-5.5 V supply aligns with 24V-to-5V industrial rails. Compared to PIC16C alternatives, the 16Kx16 program bus and 902-byte RAM deliver substantially more headroom for ladder-logic interpreters and Modbus stacks, making PIC17C766T a long-proven workhorse in factory-floor controllers.
Recommended
HVAC and Building Control Panels
The PIC17C766T-33/PT is a strong fit for commercial HVAC control boards where 50+ sensor inputs (temperature, humidity, pressure, airflow) must be scanned in real time alongside relay-controlled actuators. Its 10-bit A/D converter samples analog channels directly without external circuitry, and the 66 I/O count easily drives LCD character displays, keypads, and triac-based fan/compressor switches. The 33 MHz clock and 8.25 MIPS throughput support multi-zone scheduling algorithms while leaving CPU headroom for communication stacks. The 80-pin TQFP (PT) surface-mount package suits wave-soldered control board assemblies, and the 5 V supply rail integrates with conventional 24 VAC-to-5 VDC building-automation power designs. This part remains in active production for sustainment of installed building-management systems.
Recommended
Medical Instrument Front End
The PIC17C766T-33/PT suits medical device front-end controllers such as benchtop analyzers, infusion-pump user interfaces, and patient-monitor keypads where deterministic timing and high pin count are valued over Flash flexibility. Its 10-bit ADC digitizes sensor signals (pressure transducers, thermistor bridges) at sample rates up to ~50 ksps, and the 66 I/O pins drive membrane keypads, character LCDs, and status LEDs without external latches. The PIC17C Harvard architecture provides deterministic interrupt latency critical for safety-related signaling, while the 902-byte RAM supports patient-data buffering. Production builds use OTP for code lockdown. Engineers should verify IEC 60730 / IEC 60601 compliance at the system level and consider migrating to PIC18 for new medical designs.
Recommended
Multi-Channel Data Acquisition Board
The PIC17C766T-33/PT serves as a control MCU on multi-channel data-acquisition boards where its integrated 10-bit ADC and 66 I/O reduce BOM and PCB area. Up to 16 analog input channels can be scanned at 5-10 ksps aggregate rate, with results stored in the 902-byte RAM before transfer to a host PC over USART or to an external SD card via SPI. The 33 MHz / 8.25 MIPS throughput allows continuous-channel scanning plus digital filtering in firmware. The 80-pin TQFP package accommodates the analog and digital pinout without muxes, simplifying PCB routing for low-noise analog designs with separate analog/digital ground planes. Suitable for laboratory instruments, environmental loggers, and industrial telemetry gateways.
Automotive Body and Comfort Module
The PIC17C766T-33/PT can be deployed in non-safety automotive body-control modules such as seat controllers, mirror adjusters, climate panels, and lighting drivers where its 66 I/O and 10-bit ADC provide ample interface capacity. The 5 V supply rails are typical of body-electronics domains powered through 12 V-to-5 V regulators, and the wide operating temperature grade (-40C to +125C in the -33E/PT variant) handles under-hood and cabin extremes. PIC17C parts have a long history in automotive BCM applications. For new automotive designs, however, AEC-Q100-qualified PIC18 or dsPIC33 alternatives are recommended by Microchip. Use this part only for sustaining legacy automotive platforms.
Recommended
Test and Measurement Equipment
The PIC17C766T-33/PT serves as the user-interface and control MCU in benchtop test instruments, cable testers, and signal generators where deterministic I/O handling and integrated ADC simplify the design. Its 33 MHz performance executes rotary-encoder decoding, keypad scanning, and front-panel LCD refresh simultaneously without dropped events. The 66 I/O count supports parallel connection to DUT relays, mode switches, and indicator LEDs. The 80-pin TQFP (12x12 mm) package provides ample perimeter I/O for hand-routed prototype boards. OTP program memory locks firmware at production to prevent field tampering with calibration constants. Pair with external precision ADCs (e.g., MCP6S21 PGA + external 12-bit ADC) for high-accuracy measurements while retaining the MCU's peripheral integration.
Recommended Products Summary
Engineering reference data for PIC17C766T-33/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C766-33/PT | PIC17C766T-16/PT | PIC17C766T-33I/PT | PIC17C766T-33E/PT | PIC17C756AT-33E/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 80-pin TQFP (PT), 12x12 mm | 80-pin TQFP (PT), 12x12 mm - same | 80-pin TQFP (PT), 12x12 mm - same | 80-pin TQFP (PT), 12x12 mm - same | 80-pin TQFP (PT), 12x12 mm - same | 80-pin TQFP (PT), 12x12 mm - same |
| Clock Speed | 33 MHz | 33 MHz | 16 MHz (-52%) | 33 MHz | 33 MHz | 33 MHz |
| Instruction Cycle | 121 ns | 121 ns | 250 ns (+107%) | 121 ns | 121 ns | 121 ns |
| Program Memory | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP |
| RAM | 902 bytes | 902 bytes | 902 bytes | 902 bytes | 902 bytes | 676 bytes (-25%) |
| I/O Pins | 66 | 66 | 66 | 66 | 66 | 66 |
| Operating Temperature | 0C to +70C (commercial) | 0C to +70C (commercial) | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +125C (extended) |
| 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 |
Key Differentiators
- Industrial temperature grade option available in identical 80-pin TQFP (vs PIC17C766T-33I/PT)
- Extended temperature option for harsh environments (vs PIC17C766T-33E/PT)
- Lower-cost 16 MHz option for non-timing-critical designs (vs PIC17C766T-16/PT)
Design Notes
Decouple every VDD/VSS pair with a 100 nF ceramic capacitor placed within 5 mm of the package pin. Add a bulk 10 uF tantalum or ceramic capacitor at the supply entry point. The PIC17C766T-33/PT can source/sink up to 25 mA per I/O pin (200 mA total per port group), so use 100 ohm series resistors when driving inductive loads or long PCB traces to limit inrush and ringing. A regulated 5 V supply within 4.5-5.5 V is mandatory; an MCP1700 or LP2950 LDO provides adequate current headroom.
The 80-pin TQFP (12x12 mm) package has a typical theta_JA of approximately 50 C/W on a 4-layer 1-oz PCB. At 33 MHz with all I/O toggling, core dissipation stays below 500 mW, so junction temperature remains well within the 0C to +70C commercial range with no special thermal relief. Estimated: T_J max rise = 0.5 W x 50 C/W = 25 C above ambient, comfortable for commercial designs. For extended-temperature variants (-33E/PT), verify thermal headroom at +125C ambient.
Route the analog AVSS/AVDD pins with a star-ground connection back to the power supply rather than daisy-chaining through digital grounds. Place the 33 MHz crystal within 10 mm of OSC1/OSC2 with short, symmetric traces and a guard ground ring to reduce EMI coupling into adjacent analog inputs. Keep high-current switching traces (relay drivers, LED rows) at least 5 mm away from the crystal traces. A 4-layer PCB with dedicated ground and power planes is strongly recommended for industrial and automotive environments.
The 'T' suffix denotes tape-and-reel packaging; using tray-only PIC17C766-33/PT in production feeders causes pick-and-place errors. OTP memory cannot be reprogrammed - any code bug becomes a bricked device, so use the JW windowed variant for prototype code development, then commit final code to PIC17C766T-33/PT for production. Configure the MCLR pin with the proper RC reset network (typical 10 kohm pull-up + 100 nF to ground) or tie directly to VDD if unused, but never leave MCLR floating.
Compliance Information
RoHS/REACH/halogen status not explicitly listed in the verified distributor data; request a full material declaration from Microchip for compliance verification. The -33E/PT variant is automotive-grade suitable but not formally AEC-Q100 qualified per Microchip's product advisory.