PIC17C43-25I/PT - 8-bit 25MHz OTP MCU, 8KB ROM, 44-TQFP | Microchip
MPN: PIC17C43-25I/PT ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $12.75 | $127.50 |
| 100 | $10.85 | $1,085.00 |
| 500 | $9.45 | $4,725.00 |
| 1,000 | $8.6 | $8,600.00 |
PIC17C43-25I/PT Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program memory, working RAM, and peripheral interfaces such as timers, A/D converters, and communication ports. MCUs sit inside the broader taxonomy of embedded processors, alongside microprocessors (MPUs) and DSPs. The PIC17C43 family specifically uses Microchip's enhanced PIC architecture with a 16-bit instruction word, an 8-bit data path, and 58 single-word instructions, making it upwards-compatible with the PIC16C5X, PIC12CXXX, and PIC16CXX device families for code portability.
Key features include 8 KB of OTP program memory (organized as 4 K x 16), 454 bytes of RAM, hardware multiply, a 16-level hardware stack, and on-chip peripherals such as multiple timers, a USART, and up to 33 I/O lines. The architecture supports Harvard-style separate program and data buses, enabling single-cycle instruction fetch and execution. The 44-pin TQFP (PT) package offers a compact 10x10 mm footprint suitable for surface-mount designs while still exposing the full peripheral complement.
Typical applications include industrial control systems, legacy embedded designs, motor control interfaces, sensor monitoring nodes, and replacement of obsolete microcontrollers in long-lifecycle equipment. The 25 MHz throughput, combined with the 16-bit instruction word, provides roughly four times the code density of PIC16 devices and roughly double the execution speed at the same clock.
When designing with this part, remember that OTP (one-time-programmable) memory cannot be re-flashed; development should use a JW-windowed or E-emulation variant, with the final production code burned into PIC17C43-25I/PT. The Microchip product page recommends considering PIC18F4220 as a newer Flash-based replacement for new designs.
This page synthesizes distributor pricing, drop-in alternatives, and engineering design notes not found in the manufacturer datasheet, helping engineers evaluate the PIC17C43-25I/PT for both legacy maintenance and cross-reference applications.
Drop-in alternatives for PIC17C43-25I/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 PIC17C43-25I/PT (same form factor and footprint) — differing in Program Memory Type, Core Architecture, Maximum Clock Frequency, Package, Instruction Set Width.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC17C43-25/PT
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC17C43-25E/PT
✅ Drop-In✓ In Stock
$10.85 / Unit
View Datasheet →PIC17C43-16I/PT
✅ Drop-In✓ In Stock
$5.3 / Unit
View Datasheet →PIC17C43AT-25I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC17C43-16I/PQ
✅ Drop-In✓ In Stock
$4.82 / Unit
View Datasheet →PIC17C43-25I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Program Memory Type | OTP ROM |
| Program Memory Size | 8 KB (4K x 16) |
| RAM Size | 454 bytes |
| Maximum Clock Frequency | 25 MHz |
| Instruction Execution Time | 121 ns (8.25 MIPS) |
| Number of Instructions | 58 (single-word) |
| I/O Pins | 33 |
| Supply Voltage | 5 V |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Temperature Grade | Industrial |
| Package Type | 44-pin TQFP (PT) |
| Package Dimensions | 10 x 10 mm |
| Terminal Form | GULL WING (Surface Mount) |
| Data Bus Width | 8-bit |
| Address Bus Width | 16-bit |
| Hardware Stack Levels | 16 |
| Mounting Type | Surface Mount |
PIC17C43-25I/PT Pin Configuration
| Pin 1 | RA0 — PORTA bit 0 (digital I/O, analog input) |
| Pin 2 | RA1 — PORTA bit 1 (digital I/O, analog input) |
| Pin 3 | RA2 — PORTA bit 2 (digital I/O, analog input) |
| Pin 4 | RA3 — PORTA bit 3 (digital I/O, analog input) |
| Pin 5 | RA4 — PORTA bit 4 (digital I/O) |
| Pin 6 | RA5 — PORTA bit 5 (digital I/O) |
| Pin 7 | RA6 — PORTA bit 6 (digital I/O) |
| Pin 8 | RA7 — PORTA bit 7 (digital I/O) |
| Pin 9 | RB0 — PORTB bit 0 (digital I/O, external interrupt) |
| Pin 10 | RB1 — PORTB bit 1 (digital I/O, external interrupt) |
| Pin 11 | RB2 — PORTB bit 2 (digital I/O) |
| Pin 12 | RB3 — PORTB bit 3 (digital I/O) |
| Pin 13 | RB4 — PORTB bit 4 (digital I/O) |
| Pin 14 | RB5 — PORTB bit 5 (digital I/O) |
| Pin 15 | RB6 — PORTB bit 6 (digital I/O, ICSP clock) |
| Pin 16 | RB7 — PORTB bit 7 (digital I/O, ICSP data) |
| Pin 17 | RC0 — PORTC bit 0 (digital I/O) |
| Pin 18 | RC1 — PORTC bit 1 (digital I/O) |
| Pin 19 | RC2 — PORTC bit 2 (digital I/O) |
| Pin 20 | RC3 — PORTC bit 3 (digital I/O) |
| Pin 21 | RC4 — PORTC bit 4 (digital I/O) |
| Pin 22 | RC5 — PORTC bit 5 (digital I/O) |
| Pin 23 | RC6 — PORTC bit 6 (digital I/O, USART TX) |
| Pin 24 | RC7 — PORTC bit 7 (digital I/O, USART RX) |
| Pin 25 | RD0 — PORTD bit 0 (digital I/O) |
| Pin 26 | RD1 — PORTD bit 1 (digital I/O) |
| Pin 27 | RD2 — PORTD bit 2 (digital I/O) |
| Pin 28 | RD3 — PORTD bit 3 (digital I/O) |
| Pin 29 | RD4 — PORTD bit 4 (digital I/O) |
| Pin 30 | RD5 — PORTD bit 5 (digital I/O) |
| Pin 31 | RD6 — PORTD bit 6 (digital I/O) |
| Pin 32 | RD7 — PORTD bit 7 (digital I/O) |
| Pin 33 | RE0 — PORTE bit 0 (digital I/O, control) |
| Pin 34 | RE1 — PORTE bit 1 (digital I/O, control) |
| Pin 35 | RE2 — PORTE bit 2 (digital I/O, control) |
| Pin 36 | OSC1 — Oscillator input / external clock input |
| Pin 37 | OSC2 — Oscillator output (crystal mode) |
| Pin 38 | MCLR — Master clear (reset, active low) |
| Pin 39 | VDD — Positive supply voltage (5 V) |
| Pin 40 | VSS — Ground reference |
| Pin 41 | VDD — Positive supply voltage (5 V) |
| Pin 42 | VSS — Ground reference |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC17C43-25I/PT is suitable for 6 applications: Legacy Industrial Motor Control, Obsolete Embedded System Maintenance, Sensor Monitoring Nodes, Industrial Control Front Panels, Automotive Aftermarket Modules, Medical Device Controllers (Legacy).
Legacy Industrial Motor Control
The PIC17C43-25I/PT fits legacy industrial motor-control boards because its 33 I/O pins can drive multiple half-bridge signals, encoder inputs, and tachometer feedback channels simultaneously. The 8 KB OTP program memory (4K x 16 instructions) accommodates PID state machines, while 454 bytes of RAM buffer sensor samples between control loops. Operating at 25 MHz, the 121 ns instruction cycle supports deterministic commutation timing for brushed-DC and stepper drives that require microsecond-level response. The industrial -40 C to +85 C temperature range covers factory-floor enclosures, and the 44-pin TQFP package exposes all peripheral pins including the USART for SCADA telemetry. Compared with newer MCUs, the PIC17C43 is selected when a 10-year-old firmware base must remain source-compatible.
Recommended
Obsolete Embedded System Maintenance
The PIC17C43-25I/PT is principally used to maintain obsolete embedded systems where original firmware, PCB layout, and certification cannot be re-engineered. It supplies 8 KB of OTP memory to preserve legacy control code, 454 bytes of RAM for stack and variable storage, and 33 I/O lines that map 1:1 to the existing peripheral footprint. The 5 V single-supply operation, 25 MHz clock, and 44-pin TQFP package match the original Bill of Materials exactly, allowing field-replacement without hardware redesign. Because Microchip has placed PIC17C on last-time-buy, this part is sourced specifically for repairing equipment that must remain in service - hospitals, factory lines, military spares - rather than for new production.
Recommended
Sensor Monitoring Nodes
Distributed sensor monitoring nodes benefit from the PIC17C43-25I/PT because the 25 MHz core can sample multiple analog channels through an external ADC and run averaging algorithms within the 454-byte RAM budget. The 33 I/O lines accommodate parallel keypad or display interfaces, while the on-chip USART links to RS-485 transceivers for multi-drop sensor networks. The 8 KB OTP program memory holds Modbus or proprietary sensor protocols without external storage. Industrial -40 C to +85 C operation tolerates outdoor enclosures, and the 44-pin TQFP keeps node PCBs compact. A typical node might sample temperature, pressure, and humidity every second, transmitting aggregates over a 9600-baud serial link.
Recommended
Industrial Control Front Panels
Front-panel controllers with LCDs, keypads, and LED indicators are a strong application for the PIC17C43-25I/PT because the 33 I/O lines directly drive 4x4 keypads, character LCDs, and status LEDs without external I/O expanders. The 8 KB OTP holds menu-management and alarm-handling code, while the 25 MHz clock provides responsive keypad debouncing and LCD refresh. Industrial temperature rating supports factory control cabinets, and the 44-pin TQFP package fits behind the panel display area. The 454-byte RAM buffers display strings and key states between user interactions. Hardware multiply accelerates keypad-scan routines compared with earlier PIC16 devices.
Recommended
Automotive Aftermarket Modules
The PIC17C43-25I/PT fits aftermarket automotive modules such as performance loggers, gauge drivers, and auxiliary controllers where 33 I/O lines can interface to switches, LEDs, and CAN-bus transceivers. The 5 V supply rails from typical automotive 12 V regulators, and the 25 MHz throughput processes wheel-speed and OBD-II parsing. However, the industrial temperature grade -40 C to +85 C is borderline for under-hood applications - design engineers should consider PIC17C43-25E/PT (extended -40 C to +125 C) for engine-bay mounting. The 44-pin TQFP withstands automotive vibration when PCB is properly staked. This application preserves legacy designs that were certified before Microchip discontinued PIC17C.
Recommended
Medical Device Controllers (Legacy)
Long-lifecycle medical devices such as infusion pumps, patient monitors, and laboratory analyzers that were designed around the PIC17C43 architecture are maintained using PIC17C43-25I/PT when the regulatory filing names this exact MCU. The 33 I/O lines drive stepper motors, valve actuators, and alarm buzzers, while the 8 KB OTP holds FDA-validated firmware that cannot be re-certified on a different MCU without re-filing. The 25 MHz clock provides deterministic dosing-loop timing critical to infusion accuracy. Industrial temperature rating suits clinical environments. Engineers selecting this part for medical use must verify that Microchip's last-time-buy notification and any PCN history do not affect the regulatory submission.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C43-25I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C43-25/PT | PIC17C43-25E/PT | PIC17C43-16I/PT | PIC17C43AT-25I/PT | PIC17C43-16I/PQ |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-44 (PT) | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PQ) - same |
| Maximum Clock Frequency | 25 MHz | 25 MHz | 25 MHz | 16 MHz | 25 MHz | 16 MHz |
| Program Memory | 8 KB OTP | 8 KB OTP | 8 KB OTP | 8 KB OTP | 8 KB OTP | 8 KB OTP |
| RAM Size | 454 bytes | 454 bytes | 454 bytes | 454 bytes | 454 bytes | 454 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| Operating Temperature | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| Lifecycle Status | Last-time-buy | Last-time-buy | Last-time-buy | Last-time-buy | Last-time-buy | Last-time-buy |
Key Differentiators
- Industrial temperature grade in the 25 MHz speed slot (vs PIC17C43-25/PT)
- Highest-throughput OTP option in the PIC17C family (vs PIC17C42A-25/PT)
- Largest RAM in the 8-bit PIC OTP family at this clock speed (vs PIC16F877A-I/PT)
Design Notes
The PIC17C43-25I/PT uses OTP (one-time-programmable) memory - once the device is programmed, the code is permanent and cannot be erased or re-flashed. Development must be performed on the PIC17C43/JW windowed EPROM variant or on a PIC17C42A emulator, with the final production code burned into PIC17C43-25I/PT. Programming OTPs in-circuit requires a high-voltage (around 13 V) VPP supply on the MCLR pin during the programming cycle; verify that the production programmer supports the PIC17C family algorithm. Do not mistake OTPs for Flash parts when ordering prototypes.
Estimated: At 25 MHz clock and 5 V supply with all 33 I/O pins toggling, typical core current is approximately 25 mA, dissipating 125 mW. The TQFP-44 package has theta_JA around 50 C/W (typical 4-layer JEDEC board), yielding a junction temperature rise of roughly 6 C above ambient - well within the industrial -40 C to +85 C envelope. However, in sealed enclosures with no airflow, derate by calculating theta_JA for the actual PCB copper area; reducing copper footprint can double the thermal resistance.
Place a 0.1 uF ceramic decoupling capacitor as close as possible to each VDD pin (pins 39 and 41) with a short ground trace to the nearest VSS pin (40 or 42). Add a bulk 10 uF tantalum or aluminum capacitor near the MCU to handle transient current spikes when multiple I/O banks switch simultaneously. Route the crystal/oscillator traces (OSC1, OSC2) short and symmetric, with a ground guard ring on each side to minimize EMI coupling into adjacent I/O lines. Keep high-current traces away from the MCLR reset line to prevent false resets.
PIC17C43 parts share the same PIC17C instruction set as PIC17C42 and PIC17C44, but the PIC17C43 has the largest OTP (8 KB) and RAM (454 bytes) in the family. Do not assume all PIC17C parts have the same memory map - PIC17C42 has only 4 KB OTP and PIC17C44 has 16 KB OTP. Code compiled for PIC17C43 will not run unmodified on PIC17C42 due to memory-map differences. Always verify the target part number's memory map in the datasheet's Memory Organization section before re-targeting.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status not explicitly stated in the Verified Web Data; marked 'unknown' pending datasheet or PCN review. Microchip generally ships legacy OTP PIC17C parts in matte-tin lead-free finish, but RoHS compliance for the PIC17C family was inconsistent - verify with Microchip's product compliance system before placing RoHS-critical orders. Conflict-minerals compliance assumed per Microchip's standard corporate policy.