PIC18C242T-E/SO - 8-bit 40MHz PIC MCU 16KB OTP SOIC-28 | Microchip
MPN: PIC18C242T-E/SO ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.45 | $12.45 |
| 10 | $11.2 | $112.00 |
| 100 | $9.95 | $995.00 |
| 500 | $8.85 | $4,425.00 |
| 1,000 | $7.8 | $7,800.00 |
PIC18C242T-E/SO Overview
An 8-bit microcontroller is a small single-chip computer that integrates a CPU, program memory, RAM, peripherals (timers, A/D, communication ports), and I/O on a single die. Within the taxonomy, PIC18C242 belongs to Microcontroller -> Embedded Controller -> Integrated Circuit -> Semiconductor. The PIC18 family uses a RISC Harvard architecture with separate program and data buses, enabling single-cycle instruction execution except for branch instructions that take two cycles.
Key features include 16 KB OTP program memory (8K x 16), 512 bytes of data RAM, eight priority levels for interrupts, a single-cycle hardware multiplier, and 10 MIPS peak throughput when driven by a 40 MHz oscillator. The 28-pin SOIC variant omits the Parallel Slave Port and reduces A/D input channels to 5 compared to 40-pin package variants.
Technical depth: The PIC18C242 combines a 16-bit instruction word for compact code density with an 8-bit data path, allowing efficient C compiler code generation while keeping peripheral registers byte-addressable. The single-cycle hardware 8x8 multiplier accelerates DSP routines such as FIR filters or closed-loop control math, while prioritized interrupts reduce latency for time-critical events.
Typical applications include industrial control (sensor interfaces, motor control subsystems), automotive body electronics and instrumentation, consumer appliance control boards, and embedded data acquisition front-ends. The extended temperature range makes it suitable for harsh-environment nodes.
When designing with this part, remember that OTP memory cannot be re-programmed - use it on production-intent boards where code is final, or evaluate Flash-based PIC18F242 alternatives such as the PIC18F2420 for prototyping. Decoupling VDD with a 0.1 uF ceramic capacitor placed within 5 mm of the supply pin is essential.
This page synthesizes distributor pricing, drop-in alternatives, and engineering design notes not found in the standalone Microchip datasheet.
Drop-in alternatives for PIC18C242T-E/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 PIC18C242T-E/SO (same form factor and footprint) — differing in Core Architecture, Operating Temperature, Package, ADC, MSL Level.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18C242T-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18C242-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2420-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F2520-I/SO
✅ Drop-In✓ In Stock
$4.65 / Unit
View Datasheet →PIC18F242-I/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.5 / Unit
View Datasheet →PIC18F14K22-I/SO
✅ Drop-In✓ In Stock
$0.96 / Unit
View Datasheet →DSPIC33EV128GM004-E/P8
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.86 / Unit
View Datasheet →PIC18C242T-E/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC RISC, Harvard |
| Core Size | 8-bit |
| Maximum Clock Frequency | 40 MHz |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 16 KB (8K x 16) |
| Data RAM | 512 bytes |
| Instruction Word Width | 16-bit |
| Data Bus Width | 8-bit |
| Supply Voltage | 5 V |
| Operating Temperature Range | -40C to +125C (Extended) |
| Package / Case | 28-SOIC (0.295", 7.50 mm width) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| Peak Throughput | 10 MIPS |
| Hardware Multiplier | 8x8 single-cycle |
| Interrupt Priority Levels | 8 |
| A/D Channels (28-pin variant) | 5 |
| Parallel Slave Port | Not implemented on 28-pin variant |
| RoHS Status | Compliant |
PIC18C242T-E/SO Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (Reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2/VREF- — PORTA bit 2 / Analog input 2 / A/D VREF- |
| Pin 5 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / A/D 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 / external clock input |
| Pin 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator out / clock in |
| Pin 11 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator input |
| 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 / clock |
| Pin 17 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 18 | VSS — Ground reference |
| Pin 19 | VDD — Positive supply (5 V) |
| Pin 20 | RB0/INT0 — PORTB bit 0 / External interrupt 0 |
| Pin 21 | RB1/INT1 — PORTB bit 1 / External interrupt 1 |
| Pin 22 | RB2/INT2 — PORTB bit 2 / External interrupt 2 |
| Pin 23 | RB3/CCP2 — PORTB bit 3 / Capture/Compare/PWM 2 |
| Pin 24 | RB4 — PORTB bit 4 |
| Pin 25 | RB5/PGM — PORTB bit 5 / LVP programming |
| Pin 26 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 27 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 28 | VSS — Ground (second VSS pin for 28-SOIC) |
Typical Applications
PIC18C242T-E/SO is suitable for 6 applications: Industrial Control Systems, Automotive Body Electronics, Consumer Appliance Control, Embedded Data Acquisition, HMI / Display Driver Boards, Motor Control Subsystems.
Industrial Control Systems
The PIC18C242T-E/SO fits industrial control boards thanks to its extended -40C to +125C operating range, 40 MHz core (10 MIPS), and 8 priority interrupt levels for deterministic response to sensor and actuator events. The single-cycle 8x8 hardware multiplier accelerates PID control math and signal conditioning for closed-loop regulators. Its 28-SOIC footprint with 5 A/D channels handles a typical 4-20 mA loop front-end plus discrete digital I/O for valve or relay control, making it a strong fit for PLC expansion modules, motor-driver front-ends, and process-instrumentation nodes operating near machinery heat sources.
Recommended
Automotive Body Electronics
The PIC18C242T-E/SO suits automotive body and chassis subsystems such as instrument clusters, lighting controllers, and HVAC flap drivers where extended temperature tolerance and 5 V operation are required. Its 16 KB OTP memory holds calibration tables and lookup maps for sensor linearization, while the 8-level prioritized interrupt controller manages CAN, LIN, or PWM events with bounded latency. The 28-SOIC package is footprint-compatible with AEC-Q100 Flash alternatives like PIC18F2420-I/SO, easing long-term migration for OEMs facing PIC18C-series obsolescence.
Recommended
Consumer Appliance Control
The PIC18C242T-E/SO is well-suited for consumer appliance controllers - washing machines, dishwashers, microwave ovens, and refrigerator user-interface boards - where its 16 KB OTP holds application code and the 40 MHz core drives display multiplexing and keypad scanning. The 5 A/D channels read temperature sensors (NTC), water level probes, and motor current sense, while the hardware multiplier computes RMS and PID values for motor speed regulation. Its 28-SOIC package suits automated SMT assembly lines common in high-volume appliance production.
Recommended
Embedded Data Acquisition
The PIC18C242T-E/SO serves as a low-cost data-acquisition front-end for sensor arrays in HVAC, energy metering, and building automation. Its 5-channel 10-bit (typical for the family) A/D converter multiplexes multiple analog sensors with deterministic latency under interrupt control, while 512 bytes of RAM buffer sample bursts before UART/I2C transmission to a host. The single-cycle hardware multiplier enables on-the-fly RMS and average computations, reducing host bandwidth in distributed sensing networks.
Recommended
HMI / Display Driver Boards
The PIC18C242T-E/SO is ideal for low-cost human-machine interface modules driving character LCDs, LED matrices, and 7-segment displays. Its 40 MHz core refreshes 16-character x 2-line LCDs at smooth update rates while servicing button inputs and rotary encoders through prioritized interrupts. The 28-SOIC package's generous I/O count (PORTA, B, C, D, E subsets) supports parallel LCD data buses plus keypad matrix scanning without external logic, simplifying BOM for vending, kiosk, and instrument front panels.
Recommended
Motor Control Subsystems
The PIC18C242T-E/SO can be the supervisory MCU in BLDC, stepper, or DC-brushed motor controllers where its 40 MHz core generates PWM waveforms, handles Hall-sensor feedback, and runs current/torque control loops. The hardware 8x8 multiplier accelerates field-oriented control (FOC) math, while 5 A/D channels monitor back-EMF, current sense, and temperature. Its 28-SOIC footprint mates with half-bridge drivers like MCPWM companions in fan, pump, and small e-mobility applications.
Recommended
Recommended Products Summary
Engineering reference data for PIC18C242T-E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18C242T-I/SO | PIC18C242-E/SO | PIC18F2420-I/SO | PIC18F2520-I/SO | PIC18F242-I/SO | PIC18F14K22-I/SO | DSPIC33EV128GM004-E/P8 |
|---|---|---|---|---|---|---|---|---|
| Package | 28-SOIC (0.295", 7.50 mm) | 28-SOIC (0.295") | 28-SOIC (0.295") | 28-SOIC (0.295") | 28-SOIC (0.295") | 28-SOIC (0.295") | 28-SOIC (0.295") | 28-SOIC (variant) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core / Architecture | 8-bit PIC18 RISC | 8-bit PIC18 RISC | 8-bit PIC18 RISC | 8-bit PIC18 RISC | 8-bit PIC18 RISC | 8-bit PIC18 RISC | 8-bit PIC14 enhanced RISC | 16-bit dsPIC33 DSP |
| Program Memory Type | OTP (16 KB / 8K x 16) | OTP (16 KB) | OTP (16 KB) | Flash (16 KB) | Flash (32 KB) | Flash (16 KB) | Flash (16 KB) | Flash (128 KB) |
| Data RAM | 512 bytes | 512 bytes | 512 bytes | 768 bytes | 1536 bytes | 768 bytes | 512 bytes | 8 KB |
| Max Clock Frequency | 40 MHz (10 MIPS) | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 64 MHz | 70 MIPS |
| Operating Temperature | -40C to +125C (Extended) | -40C to +85C (Industrial) | -40C to +125C (Extended) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +125C |
| Supply Voltage | 5 V | 5 V | 5 V | 2.0 - 5.5 V | 2.0 - 5.5 V | 2.0 - 5.5 V | 1.8 - 5.5 V | 3.0 - 3.6 V |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Active | Active | Active | Active | Active |
| Approx Unit Price (qty 1) | $12.45 | ~$11.50 | ~$13.10 | ~$3.80 | ~$4.50 | ~$3.95 | ~$2.10 | ~$3.20 |
Key Differentiators
- Extended -40C to +125C operating temperature range (vs PIC18C242T-I/SO)
- OTP memory technology for high-volume production (vs PIC18F2420-I/SO)
- Single-cycle 8x8 hardware multiplier and 8-level interrupt priority (vs DSPIC33EV128GM004-E/P8)
- 28-SOIC package compatibility with PIC18F-series Flash drop-ins (vs PIC18F2520-I/SO)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 19) and a bulk 10 uF tantalum or ceramic at the board supply entry. The PIC18C242T-E/SO requires a stable 5 V rail; ripple above 50 mV can trigger brown-out resets or A/D reference drift. For noisy environments, add a ferrite bead in series with VDD and a 10 uF capacitor on the MCU side.
OTP memory cannot be erased or rewritten. Engineers accustomed to Flash-based PIC18F parts may accidentally program production code into OTP silicon and scrap boards. Always validate firmware on a PIC18F2420-I/SO (pin-compatible Flash part) before committing the OTP version to production. Estimated: about 70% of OTP-vs-Flash confusion arises from oversight in prototype-to-production handoff.
Route the ICSP pins (RB6/PGC = pin 26, RB7/PGD = pin 27, MCLR/VPP = pin 1) to a 5-pin in-circuit programming header. Keep the trace between MCLR and the ICSP header short (under 50 mm) and avoid sharing it with high-current switching signals. The 28-SOIC package's 0.295 inch (7.50 mm) body width provides ample clearance for hand-soldered prototype boards.
The PIC18C242's 28-SOIC variant exposes only 5 A/D channels (vs 8 on the 40-pin PIC18C442). If your design needs more analog inputs, add an external analog multiplexer (e.g., CD4051) or migrate to the 40-pin PIC18C442-I/SP. Add a 100 nF bypass cap on each AVDD reference pin and route analog traces away from PWM outputs to avoid coupling.
Compliance Information
RoHS and lead-free per Microchip product page. PIC18C242T-E/SO is not AEC-Q100 qualified; for AEC-Q100 applications, choose PIC18F2420-I/SO with automotive grade qualification.
