PIC17C756AT-16I/L - 8-Bit 16MHz OTP MCU 32KB Flash 50 I/O | Microchip
MPN: PIC17C756AT-16I/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $16.5 | $16.50 |
| 10 | $14.85 | $148.50 |
| 100 | $12.95 | $1,295.00 |
| 500 | $11.2 | $5,600.00 |
| 1,000 | $9.85 | $9,850.00 |
PIC17C756AT-16I/L Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory (RAM and program memory), and peripherals such as timers, ADCs, and communication interfaces. The PIC17C family sits at the upper end of Microchip's 8-bit OTP (One-Time Programmable) portfolio, above the PIC16C and below the PIC18 series. Program memory on the PIC17C756A is 16-bit wide, giving 32KB (16K x 16) of OTP storage, paired with 902 bytes of RAM, an 8-level hardware stack, and 50 user I/O lines. These hypernyms place the device in the hierarchy: microcontroller -> 8-bit MCU -> PIC17C family -> CMOS EPROM-based MCU.
Key features include an 8-channel 10-bit ADC, two USART modules, one I2C (MSSP) and one SPI peripheral, a single-cycle hardware 8x8 multiplier, and the RISC-style 58-instruction set. The instruction cycle is 121ns at 16MHz (200ns at 8MHz), and DC to 33MHz clock input is supported per family specifications.
The architecture uses a Harvard bus with separate program and data paths. The 16-bit wide program memory enables denser code per address than 14-bit PIC16 cores. An interrupt controller handles up to 17 sources with prioritized vectoring. Power management includes selectable oscillator modes (XT, HS, RC) and a power-on reset / brown-out reset block. The CMOS EPROM process delivers low operating current, and the device supports in-circuit serial programming (ICSP) for production line code loading.
Typical applications include industrial control and instrumentation, motor control front-ends, automotive subsystems (dashboards, sensors), white goods and HVAC controls, and embedded communication bridges. The 50 I/O and rich peripheral mix make it well-suited for human-machine interface boards with displays and keypads.
When designing, ensure the OTP window (the "/L" ceramic-windowed ceramic package option) is considered for prototype iteration: code revisions require UV erase. For volume production, use the OTP-only /L or /Q versions. Decoupling caps on VDD/AVDD/VSS should be placed within 5mm of each pin to keep ADC noise within 1 LSB.
This page consolidates distributor pricing for the PIC17C756AT-16I/L, pin-compatible drop-in alternatives within the PIC17C family, and practical design notes that complement - and in places extend - what the manufacturer datasheet covers.
Drop-in alternatives for PIC17C756AT-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 PIC17C756AT-16I/L (same form factor and footprint) — differing in Package, Operating Temperature, Data Bus Width, Program Memory Type, Hardware Multiplier.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC17C756AT-16/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$11.95 / Unit
View Datasheet →PIC17C756A-16I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$11.2 / Unit
View Datasheet →PIC17C756A-16E/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$16.8 / Unit
View Datasheet →PIC17C756A-33E/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.55 / Unit
View Datasheet →PIC17C752T-33/L
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$14.2 / Unit
View Datasheet →PIC17C752-16/L
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.3 / Unit
View Datasheet →PIC17C756AT-16I/L Maximum Ratings & Electrical Characteristics
| Core | PIC17C 8-bit RISC |
| Instruction Set Width | 16-bit |
| Clock Input (max) | 33 MHz |
| Clock Input (this part) | 16 MHz |
| Instruction Cycle Time | 121 ns (at 16 MHz) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 32 KB (16K x 16) |
| Data RAM | 902 bytes |
| User I/O | 50 |
| ADC | 10-bit, 8 channels |
| USART | 2 |
| I2C (MSSP) | 1 |
| SPI | 1 |
| Hardware Multiplier | 8 x 8 single-cycle |
| Supply Voltage | 4.5 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (industrial) |
| Package | 68-pin PLCC (L) 24.23 x 24.23 mm |
| Mounting Type | Surface Mount |
PIC17C756AT-16I/L Pin Configuration
| Pin 1 | RA0/AN0 — Port A bit 0 / ADC analog input 0 |
| Pin 2 | RA1/AN1 — Port A bit 1 / ADC analog input 1 |
| Pin 3 | RA2/AN2 — Port A bit 2 / ADC analog input 2 |
| Pin 4 | RA3/AN3 — Port A bit 3 / ADC analog input 3 |
| Pin 5 | RA4/AN4/T0CKI — Port A bit 4 / ADC analog input 4 / Timer0 clock |
| Pin 6 | RA5/AN5 — Port A bit 5 / ADC analog input 5 |
| Pin 7 | RA6/AN6 — Port A bit 6 / ADC analog input 6 |
| Pin 8 | RA7/AN7 — Port A bit 7 / ADC analog input 7 |
| Pin 9 | AVSS — Analog ground reference |
| Pin 10 | AVDD — Analog positive supply |
| Pin 11 | VSS — Digital ground |
| Pin 12 | VDD — Digital positive supply (4.5V to 5.5V) |
| Pin 13 | OSC1 — Oscillator input |
| Pin 14 | OSC2 — Oscillator output |
| Pin 15 | RC0 — Port C bit 0 |
| Pin 16 | RC1 — Port C bit 1 |
| Pin 17 | RC2 — Port C bit 2 |
| Pin 18 | RC3 — Port C bit 3 |
| Pin 19 | RD0 — Port D bit 0 |
| Pin 20 | RD1 — Port D bit 1 |
| Pin 21 | RD2 — Port D bit 2 |
| Pin 22 | RD3 — Port D bit 3 |
| Pin 23 | RD4 — Port D bit 4 |
| Pin 24 | RD5 — Port D bit 5 |
| Pin 25 | RD6 — Port D bit 6 |
| Pin 26 | RD7 — Port D bit 7 |
| Pin 27 | RE0 — Port E bit 0 |
| Pin 28 | RE1 — Port E bit 1 |
| Pin 29 | RE2 — Port E bit 2 |
| Pin 30 | RE3 — Port E bit 3 |
| Pin 31 | RE4 — Port E bit 4 |
| Pin 32 | RE5 — Port E bit 5 |
| Pin 33 | RE6 — Port E bit 6 |
| Pin 34 | RE7 — Port E bit 7 |
| Pin 35 | RF0 — Port F bit 0 |
| Pin 36 | RF1 — Port F bit 1 |
| Pin 37 | RF2 — Port F bit 2 |
| Pin 38 | RF3 — Port F bit 3 |
| Pin 39 | RF4 — Port F bit 4 |
| Pin 40 | RF5 — Port F bit 5 |
| Pin 41 | RF6 — Port F bit 6 / TX1 |
| Pin 42 | RF7 — Port F bit 7 / RX1 |
| Pin 43 | RG0 — Port G bit 0 |
| Pin 44 | RG1 — Port G bit 1 |
| Pin 45 | RG2 — Port G bit 2 |
| Pin 46 | RG3 — Port G bit 3 |
| Pin 47 | RG4 — Port G bit 4 |
| Pin 48 | RB0/INT — Port B bit 0 / External interrupt |
| Pin 49 | RB1 — Port B bit 1 |
| Pin 50 | RB2 — Port B bit 2 |
| Pin 51 | RB3 — Port B bit 3 |
| Pin 52 | RB4 — Port B bit 4 |
| Pin 53 | RB5 — Port B bit 5 |
| Pin 54 | RB6 — Port B bit 6 / PGC (clock) |
| Pin 55 | RB7 — Port B bit 7 / PGD (data) |
| Pin 56 | RC4/SDI/SDA — Port C bit 4 / SPI SDI / I2C SDA |
| Pin 57 | RC5/SDO — Port C bit 5 / SPI SDO |
| Pin 58 | RC6/SCK/SCL — Port C bit 6 / SPI SCK / I2C SCL |
| Pin 59 | RC7/SS — Port C bit 7 / SPI SS |
| Pin 60 | RD0/TX2 — Port D bit 0 / USART2 TX (alt mapping) |
| Pin 61 | RD1/RX2 — Port D bit 1 / USART2 RX (alt mapping) |
| Pin 62 | TX1/RG5 — USART1 TX / Port G bit 5 |
| Pin 63 | RX1/RG6 — USART1 RX / Port G bit 6 |
| Pin 64 | MCLR/VPP — Reset input / programming voltage |
| Pin 65 | VSS — Digital ground |
| Pin 66 | VDD — Digital positive supply (4.5V to 5.5V) |
| Pin 67 | RA0/OSC1 — Port A bit 0 / secondary OSC1 (alt) |
| Pin 68 | RA1/OSC2 — Port A bit 1 / secondary OSC2 (alt) |
Typical Applications
PIC17C756AT-16I/L is suitable for 6 applications: Industrial Control & Instrumentation, Motor Control Front-Ends, Automotive Subsystems, White Goods & HVAC Controllers, Embedded Communication Bridges, Human-Machine Interface (HMI) Boards.
Industrial Control & Instrumentation
The PIC17C756AT-16I/L fits industrial control boards where 50 I/O lines drive relays, sensors, and HMI displays. The 10-bit 8-channel ADC samples transducer voltages at 121ns instruction cycles, while 902 bytes of RAM buffer control-loop variables. Per DS30411, dual USART handles RS-485 bridges for SCADA nodes; MSSP drives I2C sensor buses. The 16MHz clock gives 8.25 MIPS, sufficient for PI/PWM control of valves and motor starters. Industrial grade -40C to +85C tolerates factory-floor ambient. Suggested companions: PIC18F6520 (modern Flash drop-in) and PIC16F877A (companion HMI processor).
Recommended
Motor Control Front-Ends
The PIC17C756AT-16I/L controls small DC, stepper, and BLDC motors via PWM-driven FET bridges. Per DS30411, the hardware 8x8 multiplier accelerates Park/Clark transforms in sensorless control, and 50 I/O lines drive gate drivers, Hall sensors, and fault comparators. The 32KB OTP stores vector tables and tuning constants; 902 bytes RAM holds rotor-state buffers. With 16MHz clock the 121ns instruction cycle achieves 8.25 MIPS, sufficient for 20kHz PWM with control loop headroom. For higher-speed FOC, consider PIC18F4431 or dsPIC30F2010 as migration options.
Recommended
Automotive Subsystems
The PIC17C756AT-16I/L is used in legacy automotive subsystems including instrument clusters, HVAC controllers, and sensor interfaces. Per DS30411, the dual USART supports CAN bridges via external transceivers, and 50 I/O drives dashboard LCDs, keypads, and LED indicators. The 10-bit ADC reads temperature and pressure sensors at 121ns sample-and-hold cycles. Industrial temperature grade -40C to +85C tolerates cabin ambient; for under-hood or AEC-Q100 mandated designs, migrate to PIC18F6520 or dsPIC33EV128GM004. The 32KB OTP suits fixed-function cluster firmware.
Recommended
White Goods & HVAC Controllers
The PIC17C756AT-16I/L drives white goods (washing machines, dishwashers) and HVAC thermostat controllers. The 50 I/O lines switch triacs, read user keypads, and drive 7-segment displays. Per DS30411, MSSP (I2C) connects to EEPROM, RTC, and temperature/humidity sensors; the 10-bit ADC monitors NTC thermistors and current-sensing shunts. 902 bytes RAM stores cycle state machines, and 32KB OTP holds washing/drying profiles. The 4.5V-5.5V supply rails from rectified mains are tolerated; -40C to +85C industrial range covers garage and outdoor installations.
Recommended
Embedded Communication Bridges
The PIC17C756AT-16I/L serves as a protocol bridge between RS-232, RS-485, I2C, and SPI segments in embedded gateways. Per DS30411, two USARTs enable simultaneous RS-232 and RS-485 connections; MSSP runs I2C to sensor clusters while SPI addresses external EEPROM or display drivers. The 16MHz clock with 8.25 MIPS throughput handles byte-level protocol parsing without DMA. 902 bytes RAM is adequate for ring buffers; 32KB OTP stores protocol stacks. Industrial -40C to +85C range supports outdoor enclosures. For higher throughput migration, dsPIC33EP64MC504 offers DSP-class performance.
Recommended
Human-Machine Interface (HMI) Boards
The PIC17C756AT-16I/L drives HMI boards with character LCDs, keypads, and status LEDs. Per DS30411, 50 I/O lines scan 8x8 matrix keypads and drive 4x40 character LCDs via parallel interface. The 10-bit ADC reads potentiometers and rotary encoders; the 32KB OTP stores menu trees and string tables; 902 bytes RAM holds display buffers. The 8.25 MIPS throughput debounces keys and refreshes displays at 50Hz without flicker. The 68-pin PLCC footprint simplifies PCB layout for retrofits and legacy HMI panels.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C756AT-16I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C756AT-16/PT | PIC17C756A-16I/PT | PIC17C756A-16E/PT | PIC17C756A-33E/PT | PIC17C752-16/L |
|---|---|---|---|---|---|---|
| Package | 68-PLCC (L) | 68-PLCC (L) - same | 68-PLCC (L) - same | 68-PLCC (L) - same | 68-PLCC (L) - same | 68-PLCC (L) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Clock Frequency | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 33 MHz | 16 MHz |
| Program Memory | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP | 16 KB OTP |
| RAM | 902 bytes | 902 bytes | 902 bytes | 902 bytes | 902 bytes | 678 bytes |
| User I/O | 50 | 50 | 50 | 50 | 50 | 50 |
| Temperature Grade | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +125C (Extended) | 0C to +70C (Commercial) |
| ADC | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels |
| Lifecycle | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Drop-in same-package alternative in commercial temperature grade (vs PIC17C756AT-16/PT)
- Drop-in same-package alternative at higher clock speed (vs PIC17C756A-33E/PT)
- Drop-in alternative with 50% program memory for cost-sensitive designs (vs PIC17C752-16/L)
Design Notes
PIC17C756AT-16I/L requires 4.5V to 5.5V on VDD with a separate AVDD/AVSS pair for the 10-bit ADC. Per DS30411, place a 10uF tantalum + 0.1uF ceramic on each VDD/AVDD pin within 5mm, plus a ferrite bead between digital and analog supplies. Brown-out reset is recommended at 4.0V for industrial 5V rails. Inrush current is ~20mA during ICSP programming - ensure regulator headroom or use a switcher with soft-start.
The 68-pin PLCC footprint is 24.23x24.23mm with 1.27mm pitch J-leads. Route oscillator traces on the top layer with grounded guard ring and keep traces under 10mm to avoid parasitic capacitance. Place ICSP header (PGC, PGD, MCLR, VDD, VSS) on board edge for production programming access. Estimated: a 4-layer stackup with 0.2mm dielectric yields characteristic impedance near 50 ohm for the oscillator trace.
OTP one-time-programmability means code cannot be patched after programming - prototype with the PIC17C756AT-16I/L windowed /JW variant (UV-eraseable) or use PIC18F6520 for Flash-based iteration. Per DS30411, ICSP requires MCLR held high in run mode; a 10kohm pull-up to VDD prevents spurious resets. Configuration bits must be set explicitly - leave defaults only for prototypes.
The 16MHz clock with 121ns instruction cycle requires solid oscillator layout. Per DS30411, use a crystal with ESR under 30 ohm and load capacitors sized per the crystal's CL specification (typically 15-33pF). For EMI-sensitive applications, gate the oscillator buffer when the MCU is in sleep mode. The ADC's 10-bit resolution needs source impedance under 10kohm to avoid 1 LSB errors - add a unity-gain op-amp buffer for high-impedance sensors.
Compliance Information
PIC17C756A family was released before RoHS mandate - exact compliance status not stated in verified web data. For RoHS-compliant new designs, use PIC18F6520. Not AEC-Q100 qualified; for automotive applications use AEC-Q100-grade replacements.
