PIC18C452-I/L - 8-bit 40MHz 32KB OTP MCU 44-PLCC | Microchip
MPN: PIC18C452-I/L ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.1171 | $12.12 |
| 10 | $11.21 | $112.10 |
| 100 | $9.85 | $985.00 |
| 500 | $8.72 | $4,360.00 |
| 1,000 | $7.94 | $7,940.00 |
PIC18C452-I/L Overview
A microcontroller (MCU) is a single-chip computer containing a processor core, non-volatile program memory, working RAM, and peripheral subsystems such as timers, capture/compare, ADC, and communication ports. The PIC18 family advances Microchip's PIC architecture with a 16-bit instruction word, an 8-bit data path, a hardware multiplier, and an extended register set, sitting between the legacy PIC16 and the higher-end PIC17 families in the company taxonomy. The PIC18C452 specifically is the 44-pin member of the OTP PIC18C generation, with sibling parts (PIC18C242/PIC18C252/PIC18C442) addressing 28- and 40-pin sockets.
Key features include 77 single-word instructions (most single-cycle, 100 ns at 40 MHz), a programmable 16-level hardware stack, a vectored interrupt controller with 17 sources, an enhanced USART, MSSP (SPI/I2C), CCP modules, an 8-channel 10-bit ADC, and four timer/counters. The wide operating voltage and robust interrupt structure are signature strengths of the PIC18C generation, enabling deterministic real-time control with minimal software overhead.
The PIC18C452 implements Microchip's classic Harvard RISC architecture with separate program and data buses, an arithmetic logic unit with hardware multiply, and a peripheral set designed for embedded control. The 32KB OTP program memory allows prototyping and low-volume production without external ROM, while the 1.5KB RAM buffer supports table lookups, stack frames, and protocol stacks such as UART command parsers.
Typical applications include industrial control panels, HVAC thermostat boards, motor-control signal conditioning, instrumentation front-ends, and legacy embedded systems requiring five-volt logic with PLCC socket compatibility. Modern replacements such as PIC18F452 or PIC18F458 in the same PLCC-44 footprint are recommended for new designs because the PIC18C452 is in the PIC18C generation, which Microchip indicates is mature and recommends newer devices for new development.
When designing with this device, ensure the OTP window is sealed for production code, plan code size around the 32KB ceiling, and verify the I/O drive current budget across all 33 pins. Engineers should note that Microchip's product page explicitly recommends PIC18F452 as the newer alternative, so the PIC18C452-I/L is best suited to legacy maintenance and exact-replacement scenarios rather than greenfield designs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, including a vetted list of same-footprint PIC18F parts suitable for direct PCB replacement.
Drop-in alternatives for PIC18C452-I/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 PIC18C452-I/L (same form factor and footprint) — differing in Core, Mounting Type, Package, ADC, Hardware Multiplier.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F452-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F452T-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F452-E/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F458-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F458-E/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LC452-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18C452-I/L Maximum Ratings & Electrical Characteristics
| Core | PIC18 8-bit RISC |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 32 KB (16K x 16) |
| RAM Size | 1.5 KB (1536 bytes) |
| Maximum CPU Speed | 40 MHz |
| Instruction Throughput | 10 MIPS (100 ns per instruction) |
| Instruction Set | 77 single-word instructions |
| Number of I/O Pins | 33 |
| Supply Voltage (Vdd) | 5 V nominal |
| Operating Temperature Range | -40C to +85C (Industrial, 'I' suffix) |
| Package | 44-pin PLCC (J-Lead, 16.59 x 16.59 mm) |
| Mounting Type | Surface Mount (PLCC socket compatible) |
| Oscillator Type | External (crystal/ceramic resonator or clock input) |
| ADC | 8-channel, 10-bit (per family datasheet) |
| Communication Peripherals | USART (Enhanced), MSSP (SPI/I2C) |
| Timers | 4 (Timer0-Timer3) |
| CCP Modules | 2 (per family datasheet) |
| Hardware Stack | 16-level |
| Interrupt Sources | 17 (vectored) |
| RoHS Status | Compliant |
| Packaging | Tube |
PIC18C452-I/L Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input or programming voltage input |
| 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 / ADC VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / ADC 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 | RE0/RD/AN5 — PORTE bit 0 / Parallel port read / Analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / Parallel port write / Analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / Parallel port chip select / Analog input 7 |
| Pin 11 | VDD — Positive supply voltage (5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator output / clock output (Fosc/4) |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 module I/O |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 20 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 21 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 22 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 23 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — PORTC bit 6 / USART transmit / USART clock |
| Pin 26 | RC7/RX/DT — PORTC bit 7 / USART receive / USART data |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 29 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 30 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage (5V) |
| Pin 33 | RB0/INT0 — PORTB bit 0 / External interrupt 0 |
| Pin 34 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 35 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 36 | RB3/INT3/CCP2 — PORTB bit 3 / External interrupt 3 / CCP2 alternate |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 41 | NC — Not connected (per datasheet pinout) |
| Pin 42 | NC — Not connected (per datasheet pinout) |
| Pin 43 | NC — Not connected (per datasheet pinout) |
| Pin 44 | NC — Not connected (per datasheet pinout) |
Typical Applications
PIC18C452-I/L is suitable for 6 applications: Industrial Control Panels, HVAC Thermostat Controllers, Motor Control Signal Conditioning, Instrumentation Front-Ends, Legacy Embedded System Maintenance, Five-Volt Logic Embedded Boards.
Industrial Control Panels
The PIC18C452-I/L fits industrial control panels because its 40 MHz / 10 MIPS core drives deterministic scan loops while 33 I/O pins accept switches, relay drivers, and indicator LEDs without external muxing. Industrial -40C to +85C temperature rating handles unheated cabinets near machinery; 5V supply matches legacy industrial bus drivers such as RS-232 and RS-485 transceivers. The 32KB OTP memory holds ladder-logic replacement code plus HMI state machines. Compared to a CPLD-based panel, the PIC18C452-I/L adds an integrated 10-bit ADC for analog sensor inputs (4-20 mA loopback, thermistor dividers), saving external ADC ICs. Recommended companions: PIC18F452-I/L for Flash reprogramming, MAX232 RS-232 line driver, ULN2003A relay/LED driver array.
Recommended
HVAC Thermostat Controllers
The PIC18C452-I/L suits HVAC thermostat boards because its 8-channel 10-bit ADC reads thermistor, humidity sensor, and setpoint potentiometer inputs with 1 LSB resolution adequate for +/-0.5C temperature control. The 1.5KB RAM stores daily schedule tables, the Enhanced USART links to a Wi-Fi or modem module for remote telemetry, and the 40 MHz throughput supports PID loops at sub-second intervals. The 5V supply runs from a 24VAC half-wave rectified bus common in HVAC installations. With OTP memory, code is locked once validated, preventing field tampering of safety setpoints. Recommended companions: PIC18F458-I/L when CAN bus integration to a furnace control board is required, NTC thermistor, MCP1700 3.3V LDO for auxiliary sensor rails.
Recommended
Motor Control Signal Conditioning
The PIC18C452-I/L handles motor-control signal conditioning and low-side PWM switching because its two CCP modules generate complementary PWM outputs with hardware dead-band insertion for half-bridge drivers. The 10 MIPS throughput executes field-oriented control (FOC) preprocessing for stepper and BLDC motors up to several kHz loop rates. The 33 I/O pins interface Hall-effect sensors, quadrature encoders, and direction logic without external latches. Industrial temperature rating suits motor-drive cabinet installations. Note: the PIC18C452-I/L handles signal conditioning and supervisory logic; the actual half-bridge driver should be an external IR2104 or similar gate driver. Recommended companions: PIC18F452-I/L for Flash-based prototype iteration, IR2104 gate driver, ACS712 current sensor for closed-loop current feedback.
Recommended
Instrumentation Front-Ends
The PIC18C452-I/L fits instrumentation front-ends because its 10-bit ADC acquires multiple transducer channels while the PIC18 core runs calibration averaging, linearization, and ASCII command parsing for a serial data logger. The MSSP peripheral in I2C mode talks to external EEPROM for calibration constants and RTC for time-stamping measurements. With 32KB OTP, firmware can include lookup tables for thermocouple linearization (J, K, S types) without external memory. The 5V supply tolerance is well-suited to laboratory instrumentation rails. For new designs requiring more memory or USB, PIC18F4550 in TQFP-44 (pin-compatible with re-mapping) is recommended, but the PIC18C452-I/L is appropriate for sealed, calibration-locked production units. Recommended companions: PIC18F452-I/L for Flash-based prototypes, DS1307 RTC, 24LC256 I2C EEPROM.
Recommended
Legacy Embedded System Maintenance
The PIC18C452-I/L is the correct choice when maintaining legacy boards already in field deployment where the OTP-locked code matches the OEM's regulatory certification and cannot be re-validated with Flash-based replacements. Production lines for medical, aerospace, and industrial safety equipment certified against the PIC18C452-I/L OTP signature can keep manufacturing identical units by stocking remaining last-time-buy inventory. The PLCC-44 socket allows rework swap on existing PCBs without redesign. Recommended companions: keep PIC18F452-I/L qualification data ready for the eventual transition when PIC18C452-I/L stock depletes, and a PLCC-44 extraction tool for field replacement operations.
Recommended
Five-Volt Logic Embedded Boards
The PIC18C452-I/L suits 5V logic boards because its TTL-compatible thresholds interface with HC-series buffers, 5V memory buses, and 5V LCD character displays without level shifters. 33 I/O pins drive character LCDs in 4-bit mode (11 pins), four key matrix rows/columns (8 pins), and status LEDs (4 pins) with headroom. The PIC18 instruction set makes assembly-language interrupt handlers short, leaving room in the 32KB OTP for legacy peripheral drivers (Centronics parallel, I2C, SPI). The PLCC-44 footprint matches retro computing hobbyist boards designed around the classic DIP-40 PIC17 sockets (when wired for 44-pin PLCC carriers). Recommended companions: HD44780-compatible LCD module, 4x4 matrix keypad, 74HC595 shift register for I/O expansion if more pins are needed.
Recommended
Recommended Products Summary
Engineering reference data for PIC18C452-I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F452-I/L | PIC18F452T-I/L | PIC18F452-E/L | PIC18F458-I/L | PIC18F458-E/L | PIC18LC452-I/L |
|---|---|---|---|---|---|---|---|
| Package | 44-PLCC (J-Lead) | 44-PLCC (J-Lead) - same | 44-PLCC (J-Lead) - same | 44-PLCC (J-Lead) - same | 44-PLCC (J-Lead) - same | 44-PLCC (J-Lead) - same | 44-PLCC (J-Lead) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | 32 KB OTP | 32 KB Flash | 32 KB Flash | 32 KB Flash | 32 KB Flash | 32 KB Flash | 32 KB OTP |
| RAM Size | 1.5 KB | 1.5 KB | 1.5 KB | 1.5 KB | 1.5 KB | 1.5 KB | 1.5 KB |
| Maximum Clock | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) | 40 MHz (10 MIPS) |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C (Industrial) |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 | 33 |
| CAN Peripheral | No | No | No | No | Yes (CAN 2.0B) | Yes (CAN 2.0B) | No |
| Lifecycle Status | Last-Time-Buy | Active | Active | Active | Active | Active | Last-Time-Buy |
Key Differentiators
- Microchip-recommended newer alternative available in same footprint (vs PIC18F452-I/L)
- Adds CAN peripheral option for industrial networking (vs PIC18F458-I/L)
- Extended-temperature variant in identical package (vs PIC18F452-E/L)
Design Notes
Estimated: The PIC18C452-I/L Vdd range supports 5V nominal operation. Place a 100 nF decoupling capacitor as close as possible to each Vdd/Vss pin pair (pins 11/12 and pins 31/32 on the 44-PLCC package), plus a bulk 10 uF tantalum on the main 5V rail. The PIC18C family is sensitive to Vdd noise during OTP programming, so keep analog Vdd and digital Vdd separated with a ferrite bead if your board shares ADC and digital I/O with switching loads. Recommended supply rise time: monotonic 0.05 V/ms to 4.5V minimum within 50 ms of power-on for clean MCLR reset.
Place the 44-PLCC footprint with pin 1 marker dot in the upper-left, matching the package standard. Keep the ICSP clock (PGC, pin 39) and ICSP data (PGD, pin 40) traces short (<50 mm) and isolated from switching converter switching nodes to allow reliable in-system code updates via the ICD 2 / ICD 3 / PICkit 3 programmer. The MCLR/VPP pin (pin 1) needs a 10 kohm pull-up to Vdd and a 100 nF capacitor to ground for clean reset; a diode clamp to Vdd is recommended if the system uses external reset supervisors to prevent voltage overshoot above the VPP absolute-maximum of 13.5V during ICSP programming.
Do not assume OTP memory is field-reprogrammable: PIC18C452's 32 KB OTP requires a one-time programming window, so test firmware on a PIC18F452-I/L Flash equivalent first, then lock the validated code into OTP only after full qualification. Watch for the PIC18C452 vs PIC18F452 register-layout differences: the PIC18C family uses a slightly different ADC configuration register than the PIC18F family, and assembly code that targets PIC18F ADC may behave differently on PIC18C hardware. Also note that the PIC18C452 is not recommended for new designs per Microchip's own product page, so plan qualification of the PIC18F452 or PIC18F458 as your eventual substitute before last-time-buy inventory is exhausted.
Compliance Information
RoHS and REACH compliance per Microchip product documentation. AEC-Q100 qualification status not applicable for legacy OTP MCU line - choose PIC18F452-E/L or PIC18F458-E/L for AEC-Q100 qualified Flash alternatives.
