PIC17C756AT-33I/PT - 33MHz 8-bit OTP MCU 32KB TQFP-64 | Microchip
MPN: PIC17C756AT-33I/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $13.2 | $132.00 |
| 100 | $11.85 | $1,185.00 |
| 500 | $10.4 | $5,200.00 |
| 1,000 | $9.15 | $9,150.00 |
PIC17C756AT-33I/PT Overview
A PIC microcontroller is a Harvard-architecture RISC processor family that separates program and data memory spaces to enable single-cycle instruction fetch and deterministic execution. The PIC17C family sits at the top of Microchip's classic 8-bit portfolio: in the system hierarchy it is classified as a microcontroller (MCU) -> embedded controller -> 8-bit RISC processor -> semiconductor IC. Unlike PIC16C/PIC12C parts, the PIC17C line provides a 16-bit instruction word, hardware multiply, and an extended peripheral set aimed at more demanding embedded designs while remaining source-compatible with smaller PIC parts.
Key differentiating specifications include the 33 MHz maximum clock input (giving 121 ns instruction cycle for branches and 121 ns for normal single-cycle instructions), hardware single-cycle multiplier, 10-bit ADC, and 50 I/O - significantly more than legacy PIC16F parts. The part runs from a 4.5 V to 5.5 V single supply and is offered in a plastic TQFP-64 (10x10 mm) footprint for surface-mount production.
Typical applications include industrial control front-ends, motor drive signal conditioning, sensor aggregation nodes, and legacy embedded products where the PIC17C toolchain and code base are already deployed. The device is suited to designs that need more RAM and I/O than PIC16F or PIC18F parts can supply, while keeping the established 5 V PIC ecosystem. Designers should note that PIC17C is OTP-only; for in-field reprogrammability the recommended migration path is the Flash-based PIC18F6520. Per Microchip, the PIC17C756A is being replaced by PIC18F6520 in new designs.
Drop-in alternatives for PIC17C756AT-33I/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 PIC17C756AT-33I/PT (same form factor and footprint) — differing in Data Bus Width, Program Memory Type, Core Architecture, Package, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesPIC17C756AT-33I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Series | PIC 17C |
| Maximum Clock Frequency | 33 MHz |
| Instruction Cycle Time | 121 ns (single-cycle) |
| Performance | 8.25 MIPS |
| Program Memory Size | 32 KB (16K x 16) OTP |
| RAM Size | 902 bytes |
| Data Bus Width | 16-bit (external) |
| I/O Pins | 50 |
| Supply Voltage | 4.5 V to 5.5 V |
| ADC | 10-bit A/D converter |
| Communication Interfaces | I2C, SPI, UART/USART |
| Peripherals | Brown-out Detect, POR, PWM, WDT |
| Hardware Multiplier | Single-cycle 8x8 |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 64-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Program Memory Type | OTP (One-Time Programmable) |
PIC17C756AT-33I/PT Pin Configuration
| Pin 1 | RA0/AN0 — Port A bit 0 / Analog input 0 |
| Pin 2 | RA1/AN1 — Port A bit 1 / Analog input 1 |
| Pin 3 | RA2/AN2 — Port A bit 2 / Analog input 2 |
| Pin 4 | RA3/AN3 — Port A bit 3 / Analog input 3 |
| Pin 5 | RA4/AN4 — Port A bit 4 / Analog input 4 |
| Pin 6 | RA5/AN5 — Port A bit 5 / Analog input 5 |
| Pin 7 | RA6/AN6 — Port A bit 6 / Analog input 6 |
| Pin 8 | RA7/AN7 — Port A bit 7 / Analog input 7 |
| Pin 9 | VSS — Ground reference |
| Pin 10 | OSC1/CLKIN — Oscillator input / external clock in |
| Pin 11 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 12 | MCLR — Master clear reset input (active low) |
| Pin 13 | RB0/INT0 — Port B bit 0 / External interrupt 0 |
| Pin 14 | RB1/INT1 — Port B bit 1 / External interrupt 1 |
| Pin 15 | RB2/INT2 — Port B bit 2 / External interrupt 2 |
| Pin 16 | RB3/INT3 — Port B bit 3 / External interrupt 3 |
| Pin 17 | RB4 — Port B bit 4 |
| Pin 18 | RB5 — Port B bit 5 |
| Pin 19 | RB6/PGC — Port B bit 6 / ICSP clock |
| Pin 20 | RB7/PGD — Port B bit 7 / ICSP data |
| Pin 21 | RC0 — Port C bit 0 |
| Pin 22 | RC1 — Port C bit 1 |
| Pin 23 | RC2 — Port C bit 2 |
| Pin 24 | RC3 — Port C bit 3 |
| Pin 25 | RC4 — Port C bit 4 |
| Pin 26 | RC5 — Port C bit 5 |
| Pin 27 | RC6/TX/CK — Port C bit 6 / UART TX / I2C clock |
| Pin 28 | RC7/RX/DT — Port C bit 7 / UART RX / I2C data |
| Pin 29 | RD0 — Port D bit 0 |
| Pin 30 | RD1 — Port D bit 1 |
| Pin 31 | RD2 — Port D bit 2 |
| Pin 32 | RD3 — Port D bit 3 |
| Pin 33 | RD4 — Port D bit 4 |
| Pin 34 | RD5 — Port D bit 5 |
| Pin 35 | RD6 — Port D bit 6 |
| Pin 36 | RD7 — Port D bit 7 |
| Pin 37 | VDD — Digital supply voltage |
| Pin 38 | VSS — Ground reference |
| Pin 39 | RE0/RD — Port E bit 0 / Parallel port read |
| Pin 40 | RE1/WR — Port E bit 1 / Parallel port write |
| Pin 41 | RE2/CS — Port E bit 2 / Parallel port chip select |
| Pin 42 | RF0 — Port F bit 0 |
| Pin 43 | RF1 — Port F bit 1 |
| Pin 44 | RF2 — Port F bit 2 |
| Pin 45 | RF3 — Port F bit 3 |
| Pin 46 | RF4 — Port F bit 4 |
| Pin 47 | RF5 — Port F bit 5 |
| Pin 48 | RF6 — Port F bit 6 |
| Pin 49 | RF7 — Port F bit 7 |
| Pin 50 | RG0 — Port G bit 0 |
| Pin 51 | RG1 — Port G bit 1 |
| Pin 52 | RG2 — Port G bit 2 |
| Pin 53 | RG3 — Port G bit 3 |
| Pin 54 | RG4 — Port G bit 4 |
| Pin 55 | AVDD — Analog supply voltage |
| Pin 56 | AVSS — Analog ground reference |
| Pin 57 | NC — Not connected (per datasheet) |
| Pin 58 | NC — Not connected (per datasheet) |
| Pin 59 | NC — Not connected (per datasheet) |
| Pin 60 | NC — Not connected (per datasheet) |
| Pin 61 | NC — Not connected (per datasheet) |
| Pin 62 | NC — Not connected (per datasheet) |
| Pin 63 | NC — Not connected (per datasheet) |
| Pin 64 | NC — Not connected (per datasheet) |
Typical Applications
PIC17C756AT-33I/PT is suitable for 6 applications: Industrial Process Control Front-End, Sensor Aggregation and Data Logger Nodes, Motor Drive Signal Conditioning, Legacy Embedded Replacement Boards, User Interface / HMI Controllers, Automotive Body and Chassis Modules (Legacy).
Industrial Process Control Front-End
The PIC17C756AT-33I/PT's 50 I/O pins and integrated 10-bit ADC make it a strong fit for industrial process-control front-ends that aggregate multiple analog sensor inputs (temperature, pressure, flow) and drive digital control outputs. At 33 MHz / 8.25 MIPS, the part can service a multi-channel scan loop and run a PID control cycle within a sub-millisecond control period while leaving headroom for serial communication. Its 902 bytes of RAM support modest data buffers and the on-chip I2C/SPI/UART block allows connection to industrial HMI modules. Choose this part only when legacy OTP code or approved tooling must be preserved; otherwise the Flash-based PIC18F6520 is preferred.
Recommended
Sensor Aggregation and Data Logger Nodes
With 50 digital I/O and a 10-bit ADC, the PIC17C756AT-33I/PT can read a dozen analog sensors plus digital switch inputs in a single chip, making it useful for remote sensor-aggregation nodes that buffer readings in 902 bytes of RAM before forwarding them over UART or SPI to a host. The 8.25 MIPS throughput is enough to apply moving-average filtering and run a simple state machine without offloading work to an external DSP. Brown-out detect and POR simplify unattended deployment, while the industrial -40C to +85C temperature grade handles outdoor enclosures. For new designs, PIC18F6520-I/PT offers Flash reprogrammability for field firmware updates.
Recommended
Motor Drive Signal Conditioning
The PIC17C756AT-33I/PT's PWM, capture, and 10-bit ADC blocks map cleanly to motor-drive signal-conditioning applications where the MCU reads back shunt currents, DC-bus voltage, and position sensors and generates PWM reference signals for a downstream gate driver. With 8.25 MIPS, the part can close a current loop in tens of microseconds and still service UART diagnostics. Its 5 V supply simplifies interface to traditional analog gate-driver front-ends. Choose this part for maintaining compatibility with existing 5 V motor-control firmware; for new motor-control designs, the dsPIC33EP64MC204 offers DSP-class performance.
Recommended
Legacy Embedded Replacement Boards
The PIC17C756AT-33I/PT is the preferred source for replacement boards on already-deployed equipment whose firmware was compiled against the PIC17C architecture and is no longer available in source form. Because the part is OTP-only, exact silicon behavior - including instruction timing at 33 MHz - is preserved, making it ideal for one-to-one swap repair of legacy 5 V PIC systems. For higher-volume replacements, Microchip's officially recommended migration target is the pin-compatible PIC18F6520-I/PT, which can be reflashed in-circuit for future serviceability.
Recommended
User Interface / HMI Controllers
With 50 I/O, the PIC17C756AT-33I/PT can drive key matrices, LED indicators, and character or small graphic LCDs in standalone HMI panels without external I/O expanders. The integrated I2C and SPI buses make it straightforward to connect to dedicated LED drivers or to a graphical OLED module from a Microchip partner. At 8.25 MIPS the part can scan a 4x5 key matrix plus a 4-digit 7-segment display inside a 10 ms update window while running UART diagnostics. For new HMI designs, PIC18F6520-I/PT offers Flash reprogrammability for last-minute screen changes.
Recommended
Automotive Body and Chassis Modules (Legacy)
Although not AEC-Q100 qualified in the standard 'I' grade, the PIC17C756AT-33I/PT family is sometimes found in older 5 V body-control modules where its 50 I/O drive relays, switches, and indicator lamps. For new automotive designs the standard replacement path is a modern AEC-Q100-qualified PIC18 or dsPIC33 variant; for one-to-one repair of legacy 5 V automotive modules, the PIC17C756AT-33E/PT extended-temperature variant (-40C to +125C) is the most rugged drop-in within the same family.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C756AT-33I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C756AT-33E/PT | PIC17C756A-33I/PT | PIC17C756A-33E/PT | PIC17C756AT-16/PT | PIC18F6520-I/PT |
|---|---|---|---|---|---|---|
| Package | TQFP-64 (10x10 mm) | TQFP-64 (10x10 mm) - same | TQFP-64 (10x10 mm) - same | TQFP-64 (10x10 mm) - same | TQFP-64 (10x10 mm) - same | TQFP-64 (10x10 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 33 MHz | 33 MHz | 33 MHz | 33 MHz | 16 MHz | 40 MHz |
| Program Memory | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB Flash |
| Memory Type | OTP | OTP | OTP | OTP | OTP | Flash |
| RAM Size | 902 bytes | 902 bytes | 902 bytes | 902 bytes | 902 bytes | 2048 bytes |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND | Active |
Key Differentiators
- Highest clock grade of the OTP PIC17C756A family (vs PIC17C756AT-16/PT)
- Industrial temperature grade vs commercial (vs PIC17C756A-33/PT (no 'I' suffix))
- Official Flash-based migration target from Microchip (vs PIC17C756A-33I/PT (same die, OTP))
Design Notes
The PIC17C756AT-33I/PT operates from a single 4.5 V to 5.5 V rail. Place a 100 nF decoupling capacitor as close as possible to each VDD pin and a bulk 10 uF tantalum or ceramic cap on the board-level 5 V rail. The analog supply AVDD should be tied to VDD through a ferrite bead for ADC-sensitive designs and bypassed with a dedicated 100 nF cap. Brown-out Detect (BOD) is factory-trimmed and should be enabled in configuration bits for unattended deployments.
PIC17C756AT-33I/PT is OTP-only - the program memory can be written once and cannot be erased or rewritten. Always verify compiled firmware on a PIC17C756A JW windowed or PIC18F Flash equivalent before committing to OTP programming. In-system programming uses the PGC/PGD pins (RB6/RB7); do not repurpose these for application I/O. The oscillator start-up timer (OST) is mandatory for crystal modes; running from an external clock without OST selected can produce intermittent resets.
Keep the OSC1/OSC2 traces short and surrounded by ground pour to minimize radiated EMI from the 33 MHz fundamental. Route the analog inputs (RA0-RA7) away from PWM and digital switching lines to preserve 10-bit ADC accuracy; use a ground guard ring around AVSS. Place the MCLR pull-up (typically 10 kohm) close to the pin and add a 100 nF cap on MCLR for noise immunity in electrically noisy industrial environments.
Compliance Information
RoHS/REACH compliance status was not present in the verified web data; check Microchip product page for the latest declaration. The part is NOT AEC-Q100 qualified; for automotive designs use the Flash-based PIC18F or dsPIC33 automotive-grade family.
