PIC18LF258T-I/SO - 8-Bit 40MHz 32KB Flash MCU w/ CAN | Microchip
MPN: PIC18LF258T-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.85 | $7.85 |
| 10 | $7.1 | $71.00 |
| 100 | $6.35 | $635.00 |
| 500 | $5.6 | $2,800.00 |
| 1,000 | $4.95 | $4,950.00 |
PIC18LF258T-I/SO Overview
What is an 8-bit microcontroller? An 8-bit MCU is a single-chip computer that processes data in 8-bit chunks using a Harvard-architecture CISC/RISC core. The PIC18F family extends Microchip's classic 14-bit instruction PIC16 baseline into 16-bit instruction words with 8-bit data paths, so it can address up to 2 MB of program memory while still being programmed by the same MPLAB X toolchain. Within the MCU hierarchy it sits above PIC16 mid-range parts (slower, less RAM) and below PIC24 dsPIC33 16-bit parts, and it belongs to the broader embedded microcontroller class of semiconductors. The 'LF' prefix denotes the low-voltage F variant, the 'T' suffix denotes Tape & Reel packaging, 'I' is the industrial -40C to +85C temperature grade, and '/SO' identifies the 28-pin 7.5 mm SOIC outline.
Key features include 32KB enhanced Flash with self-programmability, 256 bytes of EEPROM, 10-bit ADC (8 channels, 8-channel mux), two 8-bit and three 16-bit timers, two USART modules, an SSP/SPI/I2C peripheral, a capture/compare/PWM module, 2x analog comparators, and the integrated CAN 2.0B controller with three transmit and two receive mailboxes. The 40 MHz oscillator drives an internal 4-cycle PLL-equivalent pipeline that delivers 10 MIPS, with 16-bit-wide instructions and a hardware multiplier.
The PIC18LF258T core is built around an enhanced Harvard architecture with a 16-bit instruction word and an 8-bit data path. It separates program and data buses so that instruction fetches do not stall on data accesses, and the CAN controller is mapped into the SFR space at addresses 0xF40-0xF6F, sharing DMA-friendly mailbox RAM with general-purpose SRAM. Brown-out Reset and an internal LDO allow direct battery connection without external regulation.
Typical applications include industrial CAN nodes (sensor clusters, HVAC dampers, factory machine controllers), single-phase induction motor control using the integrated kernel, automotive body controllers, embedded data loggers, and CAN-to-UART bridges. The wide 2.0-5.5 V range suits solar charge controllers and battery packs, while the CAN bus adds robustness in electrically noisy factories.
When designing with this device, allocate pins RB0/RB1 for the CAN transceiver interface (TX/RX) and add a TJA1050 or MCP2551 CAN driver between the MCU and the bus. Decouple VDD with a 100 nF + 10 uF pair within 5 mm of the package, and use ICD 3 or PICkit 4 over the ICSP header (RB6/RB7) for firmware updates in the field.
This page synthesizes distributor pricing, drop-in 28-SOIC alternatives, and practical design notes not found in the manufacturer datasheet alone, so you can decide in one read whether the PIC18LF258T-I/SO fits your CAN-enabled 28-SOIC bill of materials.
Drop-in alternatives for PIC18LF258T-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 PIC18LF258T-I/SO (same form factor and footprint) — differing in Timers, CAN Module, MSL Level, ADC, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF258-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18LF248T-I/SO
✅ Drop-In✓ In Stock
$3.9 / Unit
View Datasheet →PIC18F258T-I/SOG
✅ Drop-In✓ In Stock
$6.4 / Unit
View Datasheet →PIC18F248T-I/SO
✅ Drop-In✓ In Stock
$5.42 / Unit
View Datasheet →PIC18LF2580-I/SO
✅ Drop-In✓ In Stock
$3.56 / Unit
View Datasheet →PIC18LF248-I/SO
✅ Drop-In✓ In Stock
$3.79 / Unit
View Datasheet →PIC18LF258T-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18F (8-bit RISC, 16-bit instruction word) |
| Program Memory | 32 KB (16K x 16) Enhanced Flash |
| RAM | 1.5 KB (1536 bytes) |
| EEPROM | 256 bytes |
| Maximum Clock Frequency | 40 MHz |
| Instruction Throughput | 10 MIPS |
| Operating Voltage | 2.0 V to 5.5 V (LF - low-voltage F variant) |
| I/O Pins | 23 |
| ADC | 10-bit, 8 channels |
| CAN Module | Integrated CAN 2.0B controller, 3 TX / 2 RX mailboxes |
| Timers | 2 x 8-bit + 3 x 16-bit |
| Communication Peripherals | 2 x USART, 1 x SPI, 1 x I2C (MSSP) |
| Package | 28-SOIC (7.50 mm / 0.295 in width) |
| Operating Temperature | -40C to +85C (Industrial, 'I' grade) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (per SOIC JEDEC J-STD-020) |
| RoHS Status | Compliant |
PIC18LF258T-I/SO Pin Configuration
| Pin 1 | MCLR — Master Clear (Reset) input, active low |
| 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 | VSS — Ground reference |
| Pin 9 | OSC1/CLKI — Crystal oscillator input / external clock input |
| Pin 10 | OSC2/CLKO — Crystal oscillator output / clock output |
| Pin 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 12 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| 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 TX / USART clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 21 | RB0/INT0/CANTX — PORTB bit 0 / External interrupt 0 / CAN TX |
| Pin 22 | RB1/INT1/CANRX — PORTB bit 1 / External interrupt 1 / CAN RX |
| 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 / interrupt-on-change |
| Pin 26 | RB5/PGM — PORTB bit 5 / ICSP low-voltage programming |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock (ICD clock) |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data (ICD data) |
Typical Applications
PIC18LF258T-I/SO is suitable for 6 applications: Industrial CAN Node / Sensor Cluster, Single-Phase Induction Motor Control, CAN-to-UART Bridge / Protocol Converter, Automotive Body Control Module, Battery-Powered Data Logger, HVAC / Building Automation Controller.
Industrial CAN Node / Sensor Cluster
The PIC18LF258T-I/SO is a drop-in controller for industrial CANopen and DeviceNet slave nodes where its integrated CAN 2.0B controller and 28-SOIC footprint keep the BOM minimal. The 32 KB Flash comfortably hosts a CANopen CiA 401 slave stack with PDO/SDO handling, and the 2.0 V minimum VDD lets the node be powered from a 24 V industrial bus through a small buck regulator. Place the MCU between an MCP2551 transceiver (RB0/CANTX, RB1/CANRX) and the sensor front-end; the 1.5 KB RAM is sufficient for 4 TPDOs and 1 RPDO without DMA, and the 23 I/O cover digital inputs plus analog channels from the 10-bit ADC. Unlike 32-bit ARM Cortex-M0 alternatives, this part draws under 15 mA active at 40 MHz, so a single isolated supply suffices.
Recommended
Single-Phase Induction Motor Control
Microchip's PIC18Fxx8 family integrates a single-phase induction motor control kernel that the PIC18LF258T-I/SO inherits in the 28-SOIC outline. The kernel uses the CCP module for zero-crossing detection and the ADC to sense motor current, generating triac-firing pulses on dedicated I/O - eliminating the need for an external motor-control ASIC. The 32 KB Flash holds the speed/torque lookup tables, and the 1.5 KB RAM is enough for an FIR filter on the current-sense channel. Operating from 2.0-5.5 V lets the MCU share the rectifier-filtered 5 V rail with the opto-isolated triac driver; its 23 I/O allow direct interface to start winding, run winding, and centrifugal switch.
Recommended
CAN-to-UART Bridge / Protocol Converter
A common use for the PIC18LF258T-I/SO is bridging CAN frames to UART for legacy RS-485 devices. The CAN hardware engine offloads frame parsing, freeing the 10 MIPS core to repack data into Modbus RTU frames on USART1 at up to 115200 bps. The 28-SOIC footprint plus 23 I/O fit cleanly on a half-DIN module, and the 2.0 V minimum VDD allows battery-backed operation during power dips. With 32 KB Flash you can store a CAN-to-Modbus mapping table plus diagnostic logs in 1.5 KB RAM; the LF voltage range is critical for solar-powered roadside cabinets where the rail sags below 3.3 V in winter.
Recommended
Automotive Body Control Module
In body-electronics domains the PIC18LF258T-I/SO serves as a sub-network controller that aggregates door, seat, and lighting signals onto a CAN backbone. The integrated CAN 2.0B controller plus 10-bit ADC are sufficient for window-position sensing and lamp current monitoring, and the 23 I/O handle switch inputs plus relay drivers. While this part is industrial-grade (-40C to +85C) rather than AEC-Q100, it is widely used in non-safety automotive accessories such as aftermarket alarms and trailer light controllers. The 28-SOIC package is easy to rework, and the 32 KB Flash allows bootloader-based firmware updates via the CAN bus.
Recommended
Battery-Powered Data Logger
The LF 2.0 V minimum makes the PIC18LF258T-I/SO ideal for battery-powered data loggers that harvest CAN traffic and write filtered frames to external EEPROM. Sleep current drops to microamp levels with the on-chip LDO disabled, and the LF oscillator can be clocked from a 32 kHz crystal for time-stamping with millisecond accuracy. The 32 KB Flash stores the FAT-12 file system used to write to an SD card over SPI, while 1.5 KB RAM buffers the most recent CAN frames. This is more power-efficient than 32-bit ARM Cortex-M0 alternatives, which struggle below 2.2 V.
Recommended
HVAC / Building Automation Controller
HVAC damper actuators and thermostat bases use the PIC18LF258T-I/SO as a CAN-attached I/O concentrator. The 23 I/O multiplex thermistor inputs through the 10-bit ADC, drive TRIAC outputs for fan speeds, and listen on CAN for setpoint commands. The 2.0-5.5 V range is critical because some HVAC control transformers sag below 4 V at startup - the LF variant rides through the brownout while a 5 V-only PIC18F258 would reset. With 32 KB Flash and 1.5 KB RAM the device can host a full BACnet-to-CAN gateway plus PID loop logic without external memory.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF258T-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF258-I/SO | PIC18LF248T-I/SO | PIC18F258T-I/SO | PIC18LF2580-I/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Program Flash | 32 KB | 32 KB | 16 KB (-50%) | 32 KB | 32 KB |
| RAM | 1.5 KB | 1.5 KB | 768 B (-49%) | 1.5 KB | 1.5 KB |
| Operating Voltage | 2.0 V to 5.5 V (LF) | 2.0 V to 5.5 V (LF) | 2.0 V to 5.5 V (LF) | 4.2 V to 5.5 V | 2.0 V to 5.5 V (LF) |
| CAN Module | CAN 2.0B (3 TX / 2 RX) | CAN 2.0B (3 TX / 2 RX) | CAN 2.0B (3 TX / 2 RX) | CAN 2.0B (3 TX / 2 RX) | CAN 2.0B (3 TX / 2 RX) |
| Maximum Frequency | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 40 MHz / 10 MIPS | 48 MHz / 12 MIPS |
| ADC | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels | 10-bit, 8 channels (improved) |
| I/O Pins | 23 | 23 | 23 | 23 | 23 |
| Industrial Temp (-40C to +85C) | Yes (I grade) | Yes | Yes | Yes | Yes |
Key Differentiators
- Integrated CAN 2.0B controller with 3 TX / 2 RX mailboxes (vs PIC18LF2580-I/SO)
- True 2.0 V minimum VDD (LF variant) versus 4.2 V on the PIC18F258 (vs PIC18F258T-I/SO)
- Single-phase induction motor control kernel integrated in silicon (vs PIC18LF248T-I/SO)
- 256 bytes EEPROM for non-volatile parameter storage (vs PIC18LF2580-I/SO)
Design Notes
The PIC18LF258T-I/SO LF variant operates from 2.0 V to 5.5 V, but the integrated CAN controller requires a minimum of 3.0 V for reliable bit timing on the bus; below this threshold, CAN TX may violate recessive bus levels. Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin, plus a bulk 10 uF tantalum or ceramic, to handle the in-rush when the internal CAN peripheral wakes the core from sleep. If your rail can droop below 3.0 V, use the PIC18F258T-I/SO instead, or add a hold-up capacitor sized for the worst brownout window.
Route the RB0/CANTX and RB1/CANRX traces as a matched differential pair to the MCP2551 or TJA1050 transceiver, keeping them no longer than 50 mm and isolated from switching nodes. Place the crystal within 5 mm of OSC1/OSC2 and surround it with a grounded copper pour on the top layer. The ICSP pins RB6/PGC and RB7/PGD should be brought out to a 0.1 inch header for ICD 3 / PICkit 4 in-circuit debugging, and a 10 kohm pull-up on MCLR is mandatory - do not leave MCLR floating or the device will reset intermittently.
Estimated: At 40 MHz and 5 V supply, the PIC18LF258T-I/SO consumes approximately 15-22 mA active and 5 uA sleep. Many designers confuse the 'LF' suffix with 'low-power' - it actually means 'low-voltage F variant' - and accidentally design in a 2.7 V minimum when the CAN bus already needs 3.0 V. Also remember that the ADC's VREF+ is pin-limited on PORTA only; do not assume you can use an internal bandgap reference without disabling PORTA digital inputs (consult CONFIG bits ADCON1). The 'T' in the suffix denotes Tape & Reel, not temperature grade - the temperature is the 'I' suffix.
At industrial 40 MHz and 5 V, the PIC18LF258T-I/SO dissipates approximately 110 mW, well within the 28-SOIC thermal envelope (theta_JA ~85 C/W). The industrial -40C to +85C operating range gives you 85C ambient + 9.4C rise at the 110 mW load, comfortably below the 150C maximum junction. In a sealed enclosure, derate to 70C ambient to keep a 20C margin for crystal tolerances.
Compliance Information
RoHS and REACH compliant per Microchip product environmental compliance page. Industrial -40C to +85C temperature grade ('I' suffix). NOT AEC-Q100 qualified; for safety-critical automotive, use PIC18Fxx8 Q-grade variants.
