PIC18C252T-I/SO - 32KB EPROM 8-bit MCU 28-SOIC | Microchip
MPN: PIC18C252T-I/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.58 | $2.58 |
| 10 | $2.4 | $24.00 |
| 100 | $2.15 | $215.00 |
| 500 | $1.92 | $960.00 |
| 1,000 | $1.74 | $1,740.00 |
PIC18C252T-I/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, RAM, non-volatile program memory (ROM/EPROM/Flash), and peripheral I/O on one die. The PIC18 family uses an enhanced RISC Harvard architecture with separate program and data buses, 16-bit wide instructions, and an 8-bit data path. MCUs sit inside the embedded computing hierarchy: microcontroller -> embedded processor -> semiconductor IC. They are the workhorse of low-power, deterministic control applications where a full application processor would be over-specified.
Key features of the PIC18C252T-I/SO include 10 MIPS peak execution (40 MHz oscillator / 4 MHz-10 MHz input clock with PLL), 8 priority levels for interrupts, a single-cycle hardware 8x8 multiplier, an external oscillator interface, and 5V single-supply operation. The EPROM-based program memory allows windowed reprogramming for prototyping and short production runs; Microchip explicitly recommends PIC18F252 (Flash) for new designs.
Architecturally, the device combines a 16-bit instruction word with an 8-bit data path, a 77-instruction set with single-word encoding, and a peripheral set that includes timers, a 10-bit A/D converter, and capture/compare/PWM modules. Power management is supported through sleep/Idle modes with fast wake-up. With OTP program memory, the PIC18C252T-I/SO suits low-volume or legacy system refreshes rather than high-volume flash production.
Typical applications include industrial control, motor control front-ends, sensor signal conditioning with on-chip ADC, automotive body and HVAC subsystems, and any 5V embedded design that still requires EPROM-based firmware storage. The wide SOIC footprint also aids hand-soldering for prototyping and field rework. When designing with this MCU, allocate sufficient decoupling near VDD/VSS pins and verify timing margins on the external oscillator, since the 10 MIPS peak assumes a clean clock reference.
Drop-in alternatives for PIC18C252T-I/SO — 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 PIC18C252T-I/SO (same form factor and footprint) — differing in Package, Core Architecture, Operating Temperature, Program Memory Size, Mounting Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesPIC18C252T-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit RISC, Harvard) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 32 KB (16K x 16) |
| RAM Size | 1.5 KB (1.5K x 8) |
| Number of I/O Pins | 22 |
| Maximum CPU Speed | 10 MIPS (40 MHz clock input) |
| Instruction Set | 77 single-word instructions, 16-bit wide |
| Interrupt Priority Levels | 8 |
| Hardware Multiplier | 8x8 single-cycle |
| Supply Voltage | 5 V (single supply) |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 28-pin SOIC (7.50 mm body width) |
| Mounting Type | Surface Mount |
| Oscillator Type | External (with PLL option) |
| A/D Converter | 10-bit (per family datasheet) |
| Packaging | Tape and Reel |
| Lifecycle | Obsolete - recommended replacement: PIC18F252-I/SO |
| RoHS Status | Compliant (per DigiKey listing) |
PIC18C252T-I/SO Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (active low) / Programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / Analog input 2 / VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input 4 / SPI Slave Select |
| Pin 8 | OSC2/CLKO — Oscillator output / Clock output |
| Pin 9 | OSC1/CLKI — Oscillator input / Clock input |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / Capture-Compare-PWM 2 |
| Pin 12 | RC2/CCP1 — PORTC bit 2 / Capture-Compare-PWM 1 |
| Pin 13 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 15 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 16 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 18 | GND — Ground reference |
| Pin 19 | GND — Ground reference |
| Pin 20 | VDD — +5V supply |
| Pin 21 | RB0/INT0 — PORTB bit 0 / External interrupt 0 |
| Pin 22 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 23 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 24 | RB3/INT3/CCP2 — PORTB bit 3 / External interrupt 3 / CCP2 (alt) |
| Pin 25 | RB4 — PORTB bit 4 |
| Pin 26 | RB5 — PORTB bit 5 |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data |
Typical Applications
PIC18C252T-I/SO is suitable for 6 applications: Industrial Control Systems, Motor Control Front-Ends, Sensor Signal Conditioning and Data Acquisition, Automotive Body and HVAC Modules, 5V Embedded Control Boards, Legacy Equipment Retrofit and Field Replacement.
Industrial Control Systems
The PIC18C252T-I/SO fits industrial control with its 10 MIPS CPU throughput, 22 I/O pins for digital sensors and actuators, 5V single supply, and -40C to +85C industrial range. The EPROM-based memory suits legacy factory-floor equipment that still requires windowed firmware updates. The 28-SOIC wide-body aids hand-soldering during field rework. With 8 priority-level interrupts and a 10-bit ADC, it can service multi-sensor acquisition loops with deterministic response, while the Harvard bus isolates real-time control from data movement. Migration to PIC18F252-I/SO is recommended for new builds, but the C variant remains in service retrofits.
Recommended
Motor Control Front-Ends
For small motor drives the PIC18C252T-I/SO provides 10 MIPS of processing power and a 10-bit ADC that handles feedback from current shunts and Hall sensors in 28-SOIC. Its 22 digital I/Os can drive gate signals to low-side MOSFETs and read quadrature encoders, while the 8 priority interrupts let a high-rate current loop preempt slower speed-loop code. The 5V supply aligns with TTL-level gate drivers, simplifying schematic design. However, modern motor control often requires higher PWM resolution than 10-bit, so PIC18F2520-I/SO is preferred for new designs.
Recommended
Sensor Signal Conditioning and Data Acquisition
The PIC18C252T-I/SO suits sensor-signal conditioning because its 10-bit ADC and 22 I/O pins handle multiple transducer channels in 28-SOIC form factor. Harvard architecture separates ADC servicing from data bus traffic, keeping sampling deterministic at 10 MIPS. The 1.5 KB RAM buffers multiple sample sets before slow ROM-resident post-processing. Industrial -40C to +85C range supports factory and outdoor cabinets. Engineers should add external op-amp front-ends to overcome the 10-bit resolution limit; otherwise PIC18F252-I/SO or PIC18F2520-I/SO offer enhanced ADC options in the same footprint.
Recommended
Automotive Body and HVAC Modules
The PIC18C252T-I/SO operates across -40C to +85C, tolerating under-hood and cabin HVAC thermal swings, while its 22 I/Os interface seat, mirror, and climate actuators in 28-SOIC. The 8 priority interrupts service CAN-style polling alongside timer-driven fan ramps. The EPROM program memory eases compliance with locked firmware builds for service warranty. New automotive designs should consider AEC-Q100 qualified Flash parts like dsPIC33EV family, but the PIC18C252T-I/SO remains present in many EOL production lines through 2026.
Recommended
5V Embedded Control Boards
The PIC18C252T-I/SO targets 5V embedded systems where 3.3V logic would force level shifters: legacy industrial PLC backplanes, 5V sensor hubs, and educational microcontroller boards in 28-SOIC. Its 10 MIPS throughput and 77-instruction RISC core are well-documented and accessible to entry-level firmware teams. The wide SOIC footprint (7.50 mm) supports 0.1 in pitch breakout adapters. Teams should prototype with EPROM and then migrate to PIC18F252-I/SO Flash for production to avoid windowed-erase cycles and obsolete-lifecycle risk.
Recommended
Legacy Equipment Retrofit and Field Replacement
The PIC18C252T-I/SO is in demand as a field-replacement MCU for installed systems where the firmware is validated against OTP EPROM behavior, especially 28-SOIC boards in industrial controllers and HVAC modules. 32 KB of EPROM lets service technicians window-erase and reprogram during commissioning without exposing flash wearout. Its -40C to +85C rating handles field thermal exposure, and the wide SOIC footprint (7.50 mm) tolerates multiple hand-solder/rework cycles. Long-term retrofit strategy should stockpile or migrate to PIC18F252-I/SO Flash, since the PIC18C252T-I/SO is officially obsolete.
Recommended
Recommended Products Summary
Engineering reference data for PIC18C252T-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F252-I/SO | PIC18C252-I/SO | PIC18F2520-I/SO | PIC18C242-I/SO | DSPIC33EV32GM002-E/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (7.50 mm) | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Program Memory | 32 KB OTP EPROM | 16 KB Flash | 32 KB OTP EPROM | 32 KB Flash | 16 KB OTP EPROM | 32 KB Flash |
| CPU Throughput | 10 MIPS | 10 MIPS | 10 MIPS | 10 MIPS | 10 MIPS | 20 MIPS (16-bit) |
| Core | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | dsPIC33 16-bit |
| RAM | 1.5 KB | 1.5 KB | 1.5 KB | 1.5 KB | 0.75 KB | 4 KB |
| I/O Pins | 22 | 22 | 22 | 22 | 22 | 21 |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +125C |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 3.3 V |
Key Differentiators
- Drop-in Flash successor avoids obsolete-lifecycle risk (vs PIC18F252-I/SO)
- Same-die, different packaging format (vs PIC18C252-I/SO)
- Direct 32 KB Flash upgrade path (vs PIC18F2520-I/SO)
Design Notes
Place a 100 nF decoupling capacitor as close as possible to each VDD pin (pin 20) and a bulk 10 uF tantalum or ceramic at the board-level VDD supply; the 28-SOIC shares one VDD and two GND pins, so routing must minimize supply loop inductance to avoid VDD droop on the 10 MIPS instruction fetches. Use a ground pour stitched around the oscillator pins (OSC1/OSC2) to prevent digital switching noise from coupling into the clock reference.
Do not assume EPROM windowing on the production tape-and-reel -SO package; only ceramic-windowed /JW packages can be UV-erased. For prototype iteration, plan a PIC18F252-I/SO swap or budget a small ceramic-windowed /JW variant. Also note the T suffix on the part number specifies tape and reel; using a tube-suffix PIC18C252-I/SO on a pick-and-place line without reeling creates production stoppages.
Keep the analog AN0-AN4 inputs away from high-frequency switching traces such as PWM outputs and oscillator nets; the 10-bit ADC aliasing margin is small at full 40 MHz instruction rate. Add a small RC low-pass filter (typically 1 kohm + 100 pF) on each analog input to limit RF ingress. Disable the digital input buffer on ANx pins used purely for analog acquisition via the CMCON register to reduce input leakage and crosstalk.
Route the ICSP clock (PGC, RB6) and data (PGD, RB7) traces with a length match and avoid stubs, since Microchip programmers rely on clean 5V signalling during in-circuit serial programming. Maintain a programming connector accessible at board edge to avoid rework that requires removing the SOIC for off-board programming. The MCLR pin (pin 1) should pull up to VDD through 10 kohm with a 100 nF cap to ground for proper reset and high-voltage programming entry.
Compliance Information
RoHS and lead-free per DigiKey listing as of 2026-09-26. AEC-Q100 not qualified; for automotive designs use dsPIC33 AEC-Q100 parts in same 28-SOIC footprint.
