PIC18C252-I/SP - 8-bit OTP MCU 32KB Flash 40MHz | Microchip
MPN: PIC18C252-I/SP ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.65 | $76.50 |
| 100 | $6.8 | $680.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.45 | $5,450.00 |
PIC18C252-I/SP Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program memory, RAM, and peripheral interfaces. The PIC18 family sits within the larger PIC RISC architecture hierarchy: PIC18C -> enhanced 8-bit PIC -> 8-bit PIC microcontroller -> microcontroller -> embedded semiconductor. PIC18C devices specifically combine Harvard architecture, 16-bit-wide instructions, and C-optimized peripheral sets, making them a step above baseline PIC16 parts in both performance and addressable memory.
Key features of the PIC18C252-I/SP include an integrated 10-bit Analog-to-Digital Converter (ADC) with multiple input channels, three timer modules, a Capture/Compare/PWM (CCP) module, and hardware serial interfaces including I2C, SPI, and USART. The wide 2.0V to 5.5V operating range and industrial -40C to +85C temperature grade suit both battery-powered and industrial environments. The OTP program memory allows one-time field programming, useful for low-cost production units where firmware changes are not anticipated.
The device implements the PIC18 instruction set with 16-bit opcodes and an 8-bit data path, supporting linear program memory addressing up to 32 KB and a banked RAM architecture. A hardware multiplier and 31-level deep stack support C compilers and interrupt-driven designs. Brown-out Reset (BOR), Watchdog Timer (WDT), and In-Circuit Serial Programming (ICSP) are integrated.
Typical applications include industrial control subsystems, appliance controllers, automotive body electronics, sensor signal conditioning with on-chip ADC, and low-cost consumer devices. The SPDIP-28 footprint is breadboard-friendly for prototyping and field-replaceable designs.
Design tip: because the PIC18C252-I/SP is OTP-based, plan firmware carefully - any code revision requires a new part. For iterative development or field updates, migrate to the flash-based PIC18F252 in the same SPDIP-28 pinout.
This page synthesizes Microchip distributor pricing, parametric comparison vs flash-based PIC18F alternatives, and practical design notes beyond the manufacturer datasheet, with content tailored for engineers maintaining legacy systems.
Drop-in alternatives for PIC18C252-I/SP — 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 PIC18C252-I/SP (same form factor and footprint) — differing in Mounting Type, ADC, Core Architecture, I/O Pins, Instruction Set.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F252-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F252-I/SP
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC18C252-I/SP Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Family | PIC18C |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 32 KB (16K x 16 words) |
| Data RAM | 1.5 KB |
| Data EEPROM | Not present |
| Maximum CPU Speed | 40 MHz |
| Performance | 10 MIPS |
| Instruction Set | 77 instructions, 16-bit opcodes |
| I/O Pins | 23 |
| ADC | 10-bit, multi-channel |
| Timers | 3 |
| CCP Modules | 1 (Capture/Compare/PWM) |
| Serial Interfaces | I2C, SPI, USART |
| Operating Voltage | 2.0 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 28-pin SPDIP (SP) |
| Mounting Type | Through-Hole |
| ICSP | Yes (In-Circuit Serial Programming) |
| Brown-Out Reset | Yes |
| Watchdog Timer | Yes |
PIC18C252-I/SP Pin Configuration
| Pin 1 | MCLR/VPP/RA5 — Master Clear (reset) input / ICSP programming voltage / alternate RA5 |
| Pin 2 | RA0/AN0 — PORTA bit 0 / ADC input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / ADC input channel 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / ADC input channel 2 |
| Pin 5 | RA3/AN3 — PORTA bit 3 / ADC input channel 3 |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | AVDD — Analog power supply |
| Pin 8 | AVSS — Analog ground |
| Pin 9 | OSC1/CLKI/RA7 — Crystal oscillator input / external clock input / PORTA bit 7 |
| Pin 10 | OSC2/CLKO/RA6 — Crystal oscillator output / clock output / PORTA bit 6 |
| Pin 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 12 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator input |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| Pin 14 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 15 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 16 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / USART transmit / USART clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART receive / USART data |
| Pin 19 | VSS — Digital ground |
| Pin 20 | VDD — Digital power 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/CCP2 — PORTB bit 3 / CCP2 alternate |
| 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
PIC18C252-I/SP is suitable for 7 applications: Industrial Control Subsystems, Appliance Control Boards, Automotive Body Electronics (Legacy), Sensor Signal Conditioning Nodes, Low-Cost Consumer Devices, Educational and Prototyping Platforms, HVAC and Environmental Controllers.
Industrial Control Subsystems
The PIC18C252-I/SP fits industrial control subsystems that need reliable 8-bit processing at 10 MIPS with on-chip ADC and serial interfaces. Its 32 KB OTP program memory accommodates moderate-sized control firmware including state machines, PID loops, and communication stacks. The industrial -40 C to +85 C temperature range and 2.0V-5.5V supply tolerance allow direct deployment on 24V-sourced factory rails with simple regulators. Placed as the main MCU on a control board, it reads sensor inputs via the 10-bit ADC, drives actuators through PWM outputs, and reports status over RS-485 via the integrated USART.
Recommended
Appliance Control Boards
The PIC18C252-I/SP is well-suited to appliance control boards where the firmware is finalized at production and the cost-sensitive SPDIP-28 package simplifies assembly. Its CCP module generates PWM for motor speed control, the 10-bit ADC monitors temperature and current sensors, and the I2C/SPI port drives character LCDs or EEPROM storage. Operating from a single 5V rail, the device replaces discrete logic with a programmable platform, reducing BOM cost while adding features like fault logging and soft-start.
Recommended
Automotive Body Electronics (Legacy)
The PIC18C252-I/SP is found in mature automotive body-electronics modules such as lighting controllers, seat controllers, and HVAC blend-door actuators where the design is locked to the PIC18C peripheral set. Its wide operating voltage tolerates load-dump events and its industrial temp range covers under-dash environments. Designers should confirm AEC-Q100 status with the specific automotive module - the standard PIC18C252-I/SP is industrial-grade, not automotive-qualified.
Recommended
Sensor Signal Conditioning Nodes
Sensor signal conditioning nodes benefit from the PIC18C252-I/SP's 10-bit ADC, hardware multiplier, and interrupt-driven peripheral set, allowing real-time linearization and filtering without external DSP. The 1.5 KB RAM supports circular buffers for moving-average filtering, while USART and I2C/SPI enable transmission to a host controller. With 23 I/O pins, the device handles multi-channel sensor aggregation in a single SPDIP-28 footprint.
Recommended
Low-Cost Consumer Devices
Cost-sensitive consumer products that lock firmware at production can leverage the PIC18C252-I/SP's low unit cost at the SPDIP-28 price point combined with integrated peripherals, eliminating external ADC, UART, and timer chips. The OTP program memory deters cloning and supports anti-counterfeit strategies. For products with firmware revisions, evaluate the flash-based PIC18F252-I/SP as a same-footprint alternative.
Recommended
Educational and Prototyping Platforms
The PIC18C252-I/SP is breadboard-friendly with its 0.1-inch pitch SPDIP-28 package, making it a solid choice for educational labs teaching embedded C programming, interrupt handling, and peripheral interfacing. Students can experiment with the 10-bit ADC, PWM generation, and serial protocols without surface-mount soldering challenges. Universities maintaining legacy curricula on PIC18C should plan migration to PIC18F252-I/SP for new lab kits.
Recommended
HVAC and Environmental Controllers
HVAC and environmental controller designs use the PIC18C252-I/SP to read temperature, humidity, and pressure sensors via the 10-bit ADC and to drive relays, fans, and valves through PWM or GPIO outputs. The integrated USART supports Modbus RTU communication with a central BMS, and the wide 2.0V-5.5V supply allows operation from 24VAC-derived rails. For new installations with firmware updates, the PIC18F252-I/SP offers the same peripheral set with flash reprogrammability.
Recommended
Recommended Products Summary
Engineering reference data for PIC18C252-I/SP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F252-I/SP | PIC18C252-I/SO |
|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-pin SPDIP (SP) | 28-pin SPDIP (SP) - same | 28-pin SOIC (SO) - different |
| Program Memory Type | OTP (32 KB) | Flash (32 KB) | OTP (32 KB) - same |
| Program Memory Size | 32 KB | 32 KB | 32 KB |
| Data RAM | 1.5 KB | 1.5 KB | 1.5 KB |
| Data EEPROM | None | 256 bytes | None |
| Maximum Clock | 40 MHz | 40 MHz | 40 MHz |
| I/O Pins | 23 | 23 | 23 |
| Lifecycle Status | Last-time-buy | Active | Last-time-buy |
| ICSP Reprogramming | No (OTP) | Yes (Flash) | No (OTP) |
Key Differentiators
- Manufacturer-recommended flash successor in same footprint (vs PIC18F252-I/SP)
- Through-hole package for prototyping and field serviceability (vs PIC18C252-I/SO)
- OTP memory provides firmware anti-tamper protection (vs PIC18F252-I/SP)
Design Notes
Estimated: do not design new products around the PIC18C252-I/SP - it is in last-time-buy status per Microchip's product page. For new designs use the flash-based PIC18F252-I/SP, which shares the same SPDIP-28 pinout and PIC18 architecture but offers in-circuit reprogrammability. If you must stay on PIC18C252-I/SP, lock the firmware early, order lifetime-buy quantities, and validate second-source supply with your distributor.
Place the 28-pin SPDIP socket on 0.1-inch (2.54 mm) pitch to allow easy firmware swaps during development. Keep the analog AVSS/AVDD traces short and use a star-ground topology to minimize ADC noise. Decouple VDD with 100 nF ceramic plus 10 uF bulk within 5 mm of the pins, and decouple AVDD with its own 100 nF cap tied to AVSS to keep ADC readings stable.
Estimated: at 40 MHz and 5V VDD, the PIC18C252-I/SP typically draws 15-20 mA active current. Brown-Out Reset (BOR) should be enabled in the configuration bits to prevent code execution at low VDD that can corrupt OTP. For battery-powered designs, switch to the LF version or use sleep modes aggressively - the integrated WDT with postscaler keeps a slow watchdog wakeup without full CPU operation.
The 10-bit ADC achieves its rated accuracy only with a low-impedance source; add an op-amp buffer if the sensor output impedance exceeds 2.5 kohm as recommended by the Microchip datasheet. Keep analog traces away from the OSC1/OSC2 crystal traces and from switching digital lines. Use the dedicated AVSS/AVDD pins even if the ADC is unused - leaving them floating can introduce noise into PORTB digital reads.
Compliance Information
RoHS/lead-free status not explicitly stated in the verified data for the /SP SPDIP-28 variant. Industrial -40C to +85C temperature grade; not AEC-Q100 qualified. Confirm exact compliance markings with Microchip or distributor documentation before placing RoHS-required orders.
