PIC17C756AT-33E/PT - 8-Bit 33MHz OTP MCU 32KB | Microchip
MPN: PIC17C756AT-33E/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $16.2 | $16.20 |
| 10 | $14.58 | $145.80 |
| 100 | $12.96 | $1,296.00 |
| 500 | $11.66 | $5,830.00 |
| 1,000 | $10.36 | $10,360.00 |
PIC17C756AT-33E/PT Overview
An OTP-based microcontroller (One-Time Programmable) is a class of non-volatile memory MCU that is programmed once at production or during firmware development and cannot be electrically erased afterward. OTP MCUs sit in the hierarchy between mask-ROM MCUs (lowest cost, longest lead) and flash-based MCUs (re-programmable, highest flexibility), making them well suited for high-volume, cost-sensitive, code-stable products where firmware revisions are infrequent. The PIC17C family represents Microchip's high-end 8-bit architecture, designed for applications requiring more computational throughput than the PIC16 family while preserving the PIC instruction-set simplicity.
Key features of the PIC17C756AT-33E/PT include 50 I/O lines, brown-out detect/reset for power-supply supervision, and a 4.5 V to 5.5 V supply range. The wide external memory interface supports both program and data expansion beyond the internal 32 KB OTP, while the 17-bit instruction word with separate 16-bit data path (x16 architecture) accelerates table reads and arithmetic operations. The 'AT' suffix indicates tape-and-reel packaging, 'E' denotes the extended temperature grade (-40 C to +125 C), and '33' specifies the 33 MHz maximum clock.
The PIC17C756AT-33E/PT is now listed as a legacy / not-recommended for new designs product on Microchip's website, with the PIC18F6520 cited as the modern migration path. Existing designs continue to be supported for production, but new projects should evaluate the flash-based PIC18F alternative unless the OTP cost structure is critical. The 64-TQFP footprint is shared with several PIC18F devices, easing future migration.
Typical applications include industrial control panels, motor-control front-ends, instrument front panels, automotive body controllers, and embedded data-acquisition systems requiring moderate computational throughput with multiple communication interfaces. Compared with PIC16 family parts, the 17C family offers roughly 2x the instruction throughput and substantially more RAM and I/O.
When designing with this device, allocate careful PCB layout for the 64-TQFP ground paddle for thermal dissipation, and reserve an external crystal or oscillator footprint for the 33 MHz clock. Brown-out reset must be configured in firmware to ensure deterministic startup across the full 4.5-5.5 V supply range.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, with cross-references to verified Microchip migration paths.
Drop-in alternatives for PIC17C756AT-33E/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-33E/PT (same form factor and footprint) — differing in Package, Operating Temperature, Core Architecture, Data Bus Width, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC17C756A-33E/PT
✅ Drop-In✓ In Stock
$7.55 / Unit
View Datasheet →PIC17C756AT-33I/PT
✅ Drop-In✓ In Stock
$9.15 / Unit
View Datasheet →PIC17C756AT-33E/L
✅ Drop-In✓ In Stock
$10.4 / Unit
View Datasheet →PIC17C756AT-16/PT
✅ Drop-In✓ In Stock
$11.95 / Unit
View Datasheet →PIC17C752T-33/L
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$14.2 / Unit
View Datasheet →PIC17C752-33E/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$11.75 / Unit
View Datasheet →PIC17C756AT-33E/PT Maximum Ratings & Electrical Characteristics
| Architecture | PIC17C 8-bit RISC |
| Core Speed | 33 MHz |
| Instruction Execution | 121 ns (single cycle), 8.25 MIPS |
| Program Memory | 32 KB (16K x 16) OTP |
| RAM | 902 bytes |
| Data Bus Width | 16-bit |
| I/O Pins | 50 |
| Supply Voltage (Vcc) | 4.5 V to 5.5 V |
| ADC | 12 channels x 10-bit |
| Communication Interfaces | I2C, SPI, UART/USART |
| Package | 64-TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +125 C (Extended, 'E') |
| Brown-out Detect/Reset | Yes |
| Instruction Set Size | 58 single-word instructions |
| ROM Type | OTP (One-Time Programmable) |
| RoHS Status | ROHS3 Compliant |
PIC17C756AT-33E/PT Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 2 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 3 | RA2/AN2 — PORTA bit 2 / Analog input 2 |
| Pin 4 | RA3/AN3 — PORTA bit 3 / Analog input 3 |
| Pin 5 | RA4/AN4 — PORTA bit 4 / Analog input 4 |
| Pin 6 | RA5/AN5 — PORTA bit 5 / Analog input 5 |
| Pin 7 | RA6/AN6 — PORTA bit 6 / Analog input 6 |
| Pin 8 | RA7/AN7 — PORTA 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 | RB0/INT0 — PORTB bit 0 / External interrupt 0 |
| Pin 13 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 14 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 15 | RB3/INT3 — PORTB bit 3 / External interrupt 3 |
| Pin 16 | RB4 — PORTB bit 4 |
| Pin 17 | RB5 — PORTB bit 5 |
| Pin 18 | RB6 — PORTB bit 6 |
| Pin 19 | RB7 — PORTB bit 7 |
| Pin 20 | VDD — Positive supply (4.5 V to 5.5 V) |
| Pin 21 | RC0 — PORTC bit 0 |
| Pin 22 | RC1 — PORTC bit 1 |
| Pin 23 | RC2 — PORTC bit 2 |
| Pin 24 | RC3 — PORTC bit 3 |
| Pin 25 | RC4 — PORTC bit 4 |
| Pin 26 | RC5 — PORTC bit 5 |
| Pin 27 | RC6 — PORTC bit 6 |
| Pin 28 | RC7 — PORTC bit 7 |
| Pin 29 | RD0 — PORTD bit 0 |
| Pin 30 | RD1 — PORTD bit 1 |
| Pin 31 | RD2 — PORTD bit 2 |
| Pin 32 | RD3 — PORTD bit 3 |
| Pin 33 | RD4 — PORTD bit 4 |
| Pin 34 | RD5 — PORTD bit 5 |
| Pin 35 | RD6 — PORTD bit 6 |
| Pin 36 | RD7 — PORTD bit 7 |
| Pin 37 | VSS — Ground reference |
| Pin 38 | RE0/RD — PORTE bit 0 / external memory read strobe |
| Pin 39 | RE1/WR — PORTE bit 1 / external memory write strobe |
| Pin 40 | RE2/CS — PORTE bit 2 / external memory chip select |
| Pin 41 | RE3 — PORTE bit 3 |
| Pin 42 | RE4 — PORTE bit 4 |
| Pin 43 | RE5 — PORTE bit 5 |
| Pin 44 | RE6 — PORTE bit 6 |
| Pin 45 | RE7 — PORTE bit 7 |
| Pin 46 | VDD — Positive supply (4.5 V to 5.5 V) |
| Pin 47 | RF0 — PORTF bit 0 |
| Pin 48 | RF1 — PORTF bit 1 |
| Pin 49 | RF2 — PORTF bit 2 |
| Pin 50 | RF3 — PORTF bit 3 |
| Pin 51 | RF4 — PORTF bit 4 |
| Pin 52 | RF5 — PORTF bit 5 |
| Pin 53 | RF6 — PORTF bit 6 |
| Pin 54 | RF7 — PORTF bit 7 |
| Pin 55 | RG0 — PORTG bit 0 |
| Pin 56 | RG1 — PORTG bit 1 |
| Pin 57 | RG2 — PORTG bit 2 |
| Pin 58 | RG3 — PORTG bit 3 |
| Pin 59 | RG4 — PORTG bit 4 |
| Pin 60 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 61 | VDD — Positive supply (4.5 V to 5.5 V) |
| Pin 62 | VSS — Ground reference |
| Pin 63 | NC — Not connected (per datasheet) |
| Pin 64 | NC — Not connected (per datasheet) |
Typical Applications
PIC17C756AT-33E/PT is suitable for 7 applications: Industrial Process Control Panels, Automotive Body and HVAC Controllers, Instrumentation and Data Acquisition Front-Ends, Motor Control and Power Inverter Front-Ends, Embedded Sensor Hub and IoT Edge Nodes, Medical and Laboratory Bench Equipment, Legacy Industrial Embedded Designs.
Industrial Process Control Panels
The PIC17C756AT-33E/PT is well suited to industrial control panel designs requiring deterministic 33 MHz throughput and rich mixed-signal integration. The 12-channel 10-bit ADC handles multiple analog sensor inputs (temperature, pressure, flow) simultaneously, while the UART/USART, SPI, and I2C peripherals interface to HMI displays, isolated RS-485 transceivers, and I/O expansion modules. The 902-byte RAM buffers serial frames and ADC sample arrays without external memory, and the 50 I/O lines drive keypads, status LEDs, and relay banks directly. With BOR and the -40 C to +125 C extended temperature grade, the device operates reliably in factory floor enclosures with wide thermal variation and noisy 24 V/5 V power rails.
Recommended
Automotive Body and HVAC Controllers
Automotive body controllers for door modules, HVAC blend doors, and seat controllers benefit from the PIC17C756AT-33E/PT's extended -40 C to +125 C temperature grade, brown-out reset, and 5 V supply tolerance across load-dump transients. The 12 ADC channels read thermistors, potentiometers, and current shunts for position feedback and diagnostics. UART/USART links to body control modules over LIN or K-line transceivers, while the 50 I/O drive MOSFET gate drivers for motors and solenoids. OTP memory locks the final firmware image against field tampering and ensures bit-for-bit reproducibility across production runs.
Recommended
Instrumentation and Data Acquisition Front-Ends
Bench-top and rack-mount instruments use the PIC17C756AT-33E/PT as a front-panel controller that aggregates analog measurements, drives displays, and bridges to a host PC or PLC. The 33 MHz core executes control loops and user-interface logic simultaneously, while the 12-channel 10-bit ADC scans thermocouple, RTD, or 4-20 mA signal conditioning outputs. UART/USART provides a service / debug console, SPI drives high-resolution graphics LCDs or external DACs, and I2C manages EEPROM calibration constants and real-time clocks. The 64-TQFP footprint is easy to route on a 4-layer PCB with mixed analog/digital ground partitioning for low-noise measurements.
Recommended
Motor Control and Power Inverter Front-Ends
Variable-frequency drives and small motor controllers place the PIC17C756AT-33E/PT in the signal-conditioning and gate-driver coordination role. The 33 MIPS throughput handles space-vector modulation, current sampling, and fault protection algorithms in real time, while the 12 ADC channels read phase currents, DC-bus voltage, and temperature sensors simultaneously. Hardware PWM peripherals drive isolated gate drivers for IGBT or MOSFET bridges, and the UART peripheral exposes a Modbus or CANopen service interface. The OTP protocol is designed for code-stable, high-volume motor-drive platforms where firmware revisions are infrequent.
Recommended
Embedded Sensor Hub and IoT Edge Nodes
Industrial IoT edge gateways and sensor hubs use the PIC17C756AT-33E/PT as a low-power aggregator that scans multiple analog and digital sensors, then transmits summary data over UART, SPI, or I2C to a host processor or radio module. The 12 ADC inputs handle 4-20 mA loops, thermistors, and bridge sensors, while the 50 I/O read contact closures, quadrature encoders, and discrete status signals. The 902-byte RAM buffers local time-series data during radio outages, and the BOR ensures clean restarts after brown-out events on battery or harvested power.
Recommended
Medical and Laboratory Bench Equipment
Bench-top analyzers, centrifuges, and laboratory automation controllers use the PIC17C756AT-33E/PT for sequencing pumps, valves, and heaters with deterministic timing. The 33 MIPS throughput executes PID loops for temperature regulation while servicing USB-UART bridges to host PCs and SPI displays for local HMI. The 12 ADC inputs read sensor signals from photodetectors, conductivity probes, and thermistors with sufficient resolution for clinical-grade readings. The extended temperature grade supports enclosure operation, and the OTP code image locks validated firmware against field modification in regulated environments.
Recommended
Legacy Industrial Embedded Designs
Long-life industrial platforms (machine controllers, security panels, smart meters) that were originally designed around the PIC17C756AT-33E/PT continue to source the part for ongoing production. Microchip maintains NRND (Not Recommended for New Designs) status rather than full obsolescence, so authorized distributors still stock and ship the device. The 64-TQFP footprint, OTP memory, and 33 MHz throughput match the original design intent exactly, allowing form-fit-function replacements without PCB rework. Designers should still plan eventual migration to the flash PIC18F6520 to avoid end-of-life risk on long-horizon programs.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C756AT-33E/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C756A-33E/PT | PIC17C756AT-33I/PT | PIC17C756AT-16/PT | PIC17C752-33E/PT |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-TQFP (10x10) | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same |
| Core Speed | 33 MHz | 33 MHz | 33 MHz | 16 MHz | 33 MHz |
| Program Memory | 32 KB OTP | 32 KB OTP | 32 KB OTP | 32 KB OTP | 16 KB OTP (-50%) |
| RAM | 902 bytes | 902 bytes | 902 bytes | 902 bytes | 454 bytes |
| Operating Temperature | -40 C to +125 C (E) | -40 C to +125 C (E) | -40 C to +85 C (I) | -40 C to +125 C (E) | -40 C to +125 C (E) |
| ADC Channels x Resolution | 12 x 10-bit | 12 x 10-bit | 12 x 10-bit | 12 x 10-bit | 12 x 10-bit |
| Packaging Media | Tape & Reel | Tray | Tape & Reel | Tape & Reel | Tray |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND |
Key Differentiators
- Identical silicon available in tray packaging for low-volume prototypes (vs PIC17C756A-33E/PT)
- Extended -40C to +125C temperature range for industrial / automotive use (vs PIC17C756AT-33I/PT)
- Higher throughput than PIC17C752 family in identical TQFP-64 footprint (vs PIC17C752-33E/PT)
- Twice the clock speed of the -16/PT variant in the same package (vs PIC17C756AT-16/PT)
Design Notes
Decouple each VDD pin (pins 20, 46, 61) with a 100 nF ceramic capacitor placed within 5 mm of the package pad, and add a bulk 10 uF tantalum or ceramic at the regulator output. The PIC17C756AT-33E/PT draws peak currents exceeding 50 mA at 33 MHz with all peripherals active; undersized decoupling can cause brown-out resets. Connect all VSS pins (9, 37, 62) to a continuous ground pour stitched with multiple vias to the inner ground plane. The BOR (brown-out reset) module is enabled by configuration fuse and protects against supply dips below 4.5 V.
The 64-TQFP 'PT' package has a thermal pad (exposed die paddle) on the underside that must be soldered to a PCB thermal land connected to the ground plane with an array of thermal vias. This provides both electrical grounding and heat dissipation. At maximum clock speed with all peripherals active, junction temperature can approach 100 C in still air without the thermal pad soldered. Estimate: at 5 V, 33 MHz, all peripherals active, IDD ~ 50 mA, Pdiss ~ 250 mW; with theta_JA ~ 40 C/W on a 4-layer PCB, junction rise is ~10 C above ambient - well within limits.
Route the 33 MHz oscillator traces (OSC1/OSC2, pins 10-11) on the top layer with the shortest possible path to the crystal or resonator, surrounded by a ground guard ring to minimize EMI coupling. Place the crystal within 5 mm of the MCU and keep digital signal traces at least 3 mm away. For ADC accuracy, isolate analog signals (RA0-RA7) from switching digital lines on separate PCB layers or with ground traces between them. The 64-TQFP 0.5 mm pitch requires precise stencil design (0.15 mm apertures) for reliable lead-free reflow assembly per IPC-7351.
Do not program the OTP memory with a code image that has not been fully validated - OTP cannot be erased and a programming error bricks the device permanently. Always use the Microchip ICD (in-circuit debugger) on the -L (PLCC) windowed package for prototype development, then program production units via gang programmers. Configuration fuses (oscillator source, BOR, watchdog, code protection) must be set correctly on first programming; verify the CONFIG1 and CONFIG2 register values in your linker script before release. NRND status: plan migration to PIC18F6520 in the same 64-TQFP footprint for new designs.
The 50 I/O pins are organized as PORTA (8), PORTB (8), PORTC (8), PORTD (8), PORTE (8), PORTF (8), and PORTG (5) - group them on the PCB by peripheral function to minimize routing congestion. UART lines should be routed away from PWM and ADC traces; SPI signals (clock, MOSI, MISO, chip select) should be short and matched in length if the SPI peripheral operates above 5 MHz. Place pull-up resistors (4.7 kohm typical) on MCLR (pin 60) and any unused interrupt pins to prevent spurious wake events. Reserved NC pins (63, 64) should be left floating or grounded per datasheet recommendations.
Compliance Information
ROHS3 compliant per ics-embedded.com product listing. Not AEC-Q100 qualified - PIC17C756A is industrial/consumer grade. Lead-free TQFP package per Microchip Pb-free roadmap. Halogen-free status not explicitly documented in available sources - request Microchip material declaration for confirmation.
