PIC18C858-I/PT - 8-bit 40MHz 32KB EPROM MCU w/ CAN | Microchip
MPN: PIC18C858-I/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.2 | $162.00 |
| 100 | $13.85 | $1,385.00 |
| 500 | $11.4 | $5,700.00 |
| 1,000 | $9.95 | $9,950.00 |
PIC18C858-I/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and programmable I/O peripherals. The PIC18C family uses Microchip's enhanced 8-bit RISC architecture with C-compiler-optimized instruction set, linear program memory addressing up to 32 Kbytes, and linear data memory addressing up to 4 Kbytes, making it suitable for embedded control applications that need deterministic real-time response.
Key features of the PIC18C858-I/PT include a 10-bit Analog-to-Digital Converter (ADC) with multiple input channels, an integrated CAN 2.0B module for automotive and industrial networking, USART, MSSP (SPI/I2C), and capture/compare/PWM peripherals. Its 40MHz clock delivers up to 10 MIPS of processing throughput, and the 68 I/O pins give designers ample headroom for keypad, LCD, sensor, and actuator interfaces.
Architecturally, the PIC18C858 uses Harvard bus architecture with separate program and data paths, an 8-bit data path, and a 16-bit instruction word. This separation allows simultaneous instruction fetch and data access, eliminating the von Neumann bottleneck. The integrated CAN peripheral provides hardware message filtering and acceptance masks, freeing the CPU from bit-stuffing tasks.
Typical applications include industrial automation controllers, automotive body and chassis ECUs, CAN-based sensor networks, building automation gateways, and embedded control systems that benefit from the integrated CAN bus. The wide operating voltage range and industrial temperature grade also support process-control installations and HVAC controllers.
When designing with this device, remember that the PIC18C858 is built on EPROM (erasable programmable read-only memory) technology and is one-time programmable (OTP) in production. The part is marked Not Recommended for new designs by Microchip, so consider flash-based successors like the PIC18F8525 for new development. Engineers should verify the ICSP programming interface and oscillator startup timing during bring-up.
Drop-in alternatives for PIC18C858-I/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 PIC18C858-I/PT (same form factor and footprint) — differing in Package, ADC, Core Architecture, Operating Temperature, CAN Module.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18C658-I/PT
✅ Drop-In✓ In Stock
$5.45 / Unit
View Datasheet →PIC18F8525-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18C858T-I/PT
✅ Drop-In✓ In Stock
$11.75 / Unit
View Datasheet →PIC18C858-E/PT
✅ Drop-In✓ In Stock
$8.91 / Unit
View Datasheet →PIC18C801-I/PT
✅ Drop-In✓ In Stock
$4.25 / Unit
View Datasheet →PIC18C858-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Core Clock Speed | 40 MHz (max) |
| Program Memory Type | EPROM (OTP) |
| Program Memory Size | 32 KB (16K x 16) |
| RAM Size | 1.5 KB |
| Data Memory Addressing | Up to 4 KB (linear) |
| I/O Pin Count | 68 |
| Supply Voltage | 4.2 V to 5.5 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 80-pin TQFP (PT) |
| Mounting Type | Surface Mount |
| ADC | 10-bit |
| CAN Module | Integrated CAN 2.0B |
| Peripherals | USART, MSSP (SPI/I2C), CCP/PWM |
PIC18C858-I/PT Pin Configuration
| Pin 1 | OSC1/CLKI — Oscillator input / external clock input |
| Pin 2 | OSC2/CLKO — Oscillator output |
| Pin 3 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 4 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 5 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 6 | RA2/AN2/VREF- — PORTA bit 2 / analog input 2 / ADC VREF- |
| Pin 7 | RA3/AN3/VREF+ — PORTA bit 3 / analog input 3 / ADC VREF+ |
| Pin 8 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 9 | RA5/AN4 — PORTA bit 5 / analog input 4 |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply (4.2V-5.5V) |
| 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/PGC — PORTB bit 6 / ICSP clock |
| Pin 19 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 20 | VSS — Ground reference |
| Pin 21 | VDD — Positive supply |
| Pin 22 | RC0/T1CKI — PORTC bit 0 / Timer1 clock input |
| Pin 23 | RC1/CCP2 — PORTC bit 1 / Capture/Compare/PWM 2 |
| Pin 24 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Pin 25 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 26 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 27 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 28 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 29 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 30 | RD0/PSP0 — PORTD bit 0 / parallel slave port data 0 |
| Pin 31 | RD1/PSP1 — PORTD bit 1 / parallel slave port data 1 |
| Pin 32 | RD2/PSP2 — PORTD bit 2 / parallel slave port data 2 |
| Pin 33 | RD3/PSP3 — PORTD bit 3 / parallel slave port data 3 |
| Pin 34 | RD4/PSP4 — PORTD bit 4 / parallel slave port data 4 |
| Pin 35 | RD5/PSP5 — PORTD bit 5 / parallel slave port data 5 |
| Pin 36 | RD6/PSP6 — PORTD bit 6 / parallel slave port data 6 |
| Pin 37 | RD7/PSP7 — PORTD bit 7 / parallel slave port data 7 |
| Pin 38 | VSS — Ground reference |
| Pin 39 | VDD — Positive supply |
| Pin 40 | RE0/RD — PORTE bit 0 / parallel slave port read |
| Pin 41 | RE1/WR — PORTE bit 1 / parallel slave port write |
| Pin 42 | RE2/CS — PORTE bit 2 / parallel slave port chip select |
| Pin 43 | RF0 — PORTF bit 0 |
| Pin 44 | RF1 — PORTF bit 1 |
| Pin 45 | RF2 — PORTF bit 2 |
| Pin 46 | RF3 — PORTF bit 3 |
| Pin 47 | RF4 — PORTF bit 4 |
| Pin 48 | RF5 — PORTF bit 5 |
| Pin 49 | RF6 — PORTF bit 6 |
| Pin 50 | RF7 — PORTF bit 7 |
| Pin 51 | VSS — Ground reference |
| Pin 52 | VDD — Positive supply |
| Pin 53 | RG0 — PORTG bit 0 |
| Pin 54 | RG1 — PORTG bit 1 |
| Pin 55 | RG2 — PORTG bit 2 |
| Pin 56 | RG3 — PORTG bit 3 |
| Pin 57 | RG4 — PORTG bit 4 |
| Pin 58 | AVDD — Analog positive supply |
| Pin 59 | AVSS — Analog ground |
| Pin 60 | CANTX — CAN bus transmit output |
| Pin 61 | CANRX — CAN bus receive input |
| Pin 62 | VSS — Ground reference |
| Pin 63 | VDD — Positive supply |
| Pin 64 | RH0 — PORTH bit 0 (external memory bus) |
| Pin 65 | RH1 — PORTH bit 1 (external memory bus) |
| Pin 66 | RH2 — PORTH bit 2 (external memory bus) |
| Pin 67 | RH3 — PORTH bit 3 (external memory bus) |
| Pin 68 | RH4 — PORTH bit 4 (external memory bus) |
| Pin 69 | RH5 — PORTH bit 5 (external memory bus) |
| Pin 70 | RH6 — PORTH bit 6 (external memory bus) |
| Pin 71 | RH7 — PORTH bit 7 (external memory bus) |
| Pin 72 | VSS — Ground reference |
| Pin 73 | VDD — Positive supply |
| Pin 74 | RJ0 — PORTJ bit 0 (external memory bus) |
| Pin 75 | RJ1 — PORTJ bit 1 (external memory bus) |
| Pin 76 | RJ2 — PORTJ bit 2 (external memory bus) |
| Pin 77 | RJ3 — PORTJ bit 3 (external memory bus) |
| Pin 78 | RJ4 — PORTJ bit 4 (external memory bus) |
| Pin 79 | RJ5 — PORTJ bit 5 (external memory bus) |
| Pin 80 | RJ6 — PORTJ bit 6 (external memory bus) |
Typical Applications
PIC18C858-I/PT is suitable for 6 applications: Industrial CAN Network Node, Automotive Body Control Module, Building Automation Gateway, Process Control Sensor Hub, HVAC Controller Board, Embedded CAN-to-Serial Bridge.
Industrial CAN Network Node
The PIC18C858-I/PT is purpose-built for industrial CAN network nodes thanks to its integrated CAN 2.0B module with hardware acceptance filtering. At 40MHz it delivers 10 MIPS, comfortably handling CAN 2.0B message processing at 1 Mbps alongside sensor sampling via the 10-bit ADC. The 68 I/O pins connect directly to digital sensors, opto-isolated inputs, and relay drivers typical of industrial control cabinets. Placed on a CAN bus backbone with a TJA1050 transceiver, it forms a slave node reading field sensors and broadcasting status frames. The 4.2-5.5V supply matches 5V industrial rails directly. Trade-off: EPROM requires pre-programmed parts - consider PIC18F8525 for field-updateable firmware.
Recommended
Automotive Body Control Module
Automotive body control modules benefit from the PIC18C858-I/PT's combination of 32KB EPROM, integrated CAN, and 68 I/O pins. Window, mirror, lighting, and door-lock actuators can be driven directly through high-current I/O ports while CAN connectivity links the BCM to the vehicle bus. The 10-bit ADC reads switch and sensor inputs for debounced control decisions. Operating from a regulated 5V rail with industrial temperature rating, it suits under-dash automotive environments. The CAN hardware filtering offloads message routing from the CPU, leaving cycles for body-control logic. Note: For safety-critical systems requiring ASIL compliance, pair with an external watchdog and consider newer PIC18F variants with functional safety documentation.
Recommended
Building Automation Gateway
Building automation gateways bridge HVAC, lighting, and security subsystems using the PIC18C858-I/PT's CAN module plus USART and MSSP peripherals. The 32KB EPROM stores gateway routing tables and protocol converters, while 1.5KB RAM handles message buffering. The 68 I/O pins drive status LEDs, keypads, and LCD displays common to building controllers. Running at 40MHz it converts between BACnet, Modbus, and CAN protocols in real time. The 5V supply matches typical building-automation backplane rails, and the -40C to +85C industrial range covers mechanical-room environments. Trade-off: EPROM programming requires a parallel programmer at production - the PIC18F8525-I/PT offers ICSP for in-the-field firmware updates.
Recommended
Process Control Sensor Hub
Process control sensor hubs use the PIC18C858-I/PT to aggregate multiple analog and digital sensors and broadcast readings over CAN. The 10-bit ADC multiplexes across multiple process variables (temperature, pressure, flow), while the integrated CAN module transmits standardized frames to a central PLC. The 68 I/O pins accommodate digital sensor arrays plus HMI keypad input. At 10 MIPS the MCU handles linearization math, calibration lookups, and CAN protocol stack simultaneously. The 4.2-5.5V supply operates from a 5V regulated industrial rail. The wide temperature range supports outdoor and factory-floor deployments. Compared to a discrete ADC + microcontroller solution, this integrated part reduces BOM count and PCB footprint.
Recommended
HVAC Controller Board
HVAC controller boards leverage the PIC18C858-I/PT for fan, compressor, and valve control loops. The CCP/PWM peripherals generate variable-speed drive signals for brushless DC fans, while the ADC reads temperature sensors from multiple zones. The integrated CAN bus links indoor units to the building management system. With 32KB of program memory, control loop firmware plus scheduling logic fits comfortably. The 1.5KB RAM handles setpoint storage and PID working variables. Operating from a 5V supply with industrial temperature grade, the MCU suits rooftop unit and air-handler installations. For new designs, migrate to PIC18F8525-I/PT to gain flash reprogrammability and field firmware updates.
Recommended
Embedded CAN-to-Serial Bridge
A CAN-to-serial bridge application uses the PIC18C858-I/PT to convert between CAN 2.0B frames and RS-232/RS-485 serial traffic for legacy equipment integration. The CAN peripheral handles incoming automotive or industrial frames, while the USART drives the serial port at programmable baud rates. The MSSP peripheral can additionally support SPI-to-CAN bridging. With 68 I/O pins, status LEDs and configuration switches fit alongside the comms interfaces. The 32KB EPROM holds the protocol-conversion state machine and configuration tables. Operating at 40MHz the bridge sustains full-duplex serial plus 1 Mbps CAN without frame drops. Trade-off: For high-throughput bridging with multi-message buffering, the larger RAM on PIC18F8525 is preferable.
Recommended
Recommended Products Summary
Engineering reference data for PIC18C858-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18C658-I/PT | PIC18F8525-I/PT | PIC18C858T-I/PT | PIC18C858-E/PT | PIC18C801-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-80 (PT) | TQFP-80 (PT) - same | TQFP-80 (PT) - same | TQFP-80 (PT) - same | TQFP-80 (PT) - same | TQFP-80 (PT) - same |
| Program Memory | 32 KB EPROM | 16 KB EPROM (-50%) | 32 KB Flash (same size, in-system programmable) | 32 KB EPROM (same) | 32 KB EPROM (same) | 0 KB (external memory only) |
| RAM Size | 1.5 KB | 1.5 KB (same) | 4 KB (+167%) | 1.5 KB (same) | 1.5 KB (same) | 1.5 KB (same) |
| Memory Type | EPROM (OTP) | EPROM (OTP) | Flash (in-system programmable) | EPROM (OTP) | EPROM (OTP) | External memory only |
| Core Clock Speed | 40 MHz | 40 MHz (same) | 40 MHz (same) | 40 MHz (same) | 40 MHz (same) | 40 MHz (same) |
| CAN Module | Yes (integrated CAN 2.0B) | Yes (integrated CAN 2.0B) | Yes (integrated CAN 2.0B) | Yes (integrated CAN 2.0B) | Yes (integrated CAN 2.0B) | No (external memory only) |
| Operating Temperature | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +125 C (Extended) | -40 C to +85 C (Industrial) |
Key Differentiators
- Integrated CAN 2.0B peripheral with hardware filtering (vs PIC18C801-I/PT)
- 32 KB EPROM program memory (vs PIC18C658-I/PT)
- Flash-based successor path with same peripherals (vs PIC18F8525-I/PT)
Design Notes
The PIC18C858-I/PT operates from a single 4.2V to 5.5V supply. Place a 100nF decoupling capacitor close to each VDD pin (multiple VDD pins on the TQFP-80 package) and a bulk 10uF tantalum or ceramic capacitor on the board supply rail. Use separate analog (AVDD) and digital (VDD) supplies tied together at a single point near the IC if the ADC is in use, with a ferrite bead to reduce digital switching noise coupling into analog measurements.
The PIC18C858 uses EPROM (OTP) memory, so firmware must be fully validated before production programming. Unlike flash-based PIC18F variants, there is no in-circuit reprogramming option. Engineers should prototype on a flash-based equivalent (e.g., PIC18F8525-I/PT) to avoid scrapping EPROM parts during firmware iteration. The part is also marked NRND (Not Recommended for new designs) by Microchip - verify the end product's lifecycle support window before committing to this part in long-life designs.
Route the CANRX and CANTX pins to the CAN transceiver (e.g., TJA1050) using a matched-impedance differential pair, keeping the traces short and away from switching nodes. Place the oscillator crystal as close to OSC1/OSC2 as possible with ground guard traces. The 80-pin TQFP package has a thermal pad - solder it to a ground copper pour for improved thermal dissipation, especially at 40MHz operation. Avoid running noisy digital signals parallel to analog inputs to minimize ADC crosstalk.
Compliance Information
RoHS, REACH, and lead-free status not explicitly provided in the verified web data. PIC18C858 is an older EPROM-based MCU (introduced ~1999), predating many modern compliance certifications. Marked NRND (Not Recommended for new designs) by Microchip as of 2026-09-26.
