PIC17C42A-16/P - 8-Bit OTP MCU, 16MHz, 4KB, 40-PDIP | Microchip
MPN: PIC17C42A-16/P ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.25 | $112.50 |
| 100 | $9.8 | $980.00 |
| 500 | $8.6 | $4,300.00 |
| 1,000 | $7.45 | $7,450.00 |
PIC17C42A-16/P Overview
What is a PIC microcontroller? A PIC microcontroller is a family of RISC-based microcontrollers from Microchip Technology that combine a CPU core, program memory, data RAM, peripherals, and I/O pins on a single CMOS die. PIC microcontrollers sit in the broader hierarchy of microcontroller -> embedded controller -> semiconductor IC, and the PIC17C sub-family specifically targets higher-performance 8-bit designs that need more code space, more I/O, and hardware features beyond what the PIC16C5X and PIC16CXX devices provide.
Key features of the PIC17C42A-16/P include 33 digital I/O pins, 2 capture inputs, 2 PWM outputs, 2 x 8-bit plus 2 x 16-bit timers (4 timer modules total), a USART for serial communication, external memory addressing, and external oscillator support. The device is OTP (One-Time-Programmable) for code storage and operates across the standard industrial temperature range of -40C to +85C from a 5 V supply.
Architecturally, the PIC17C42A uses a Harvard RISC core with only 58 single-word instructions, an 8-level hardware stack, and interrupt handling suited to demanding real-time control. Compared to the older PIC16C5X, it adds extended instructions, wider addressing, and richer peripherals while remaining source-compatible with the PIC16CXX family, allowing designers to upgrade performance without rewriting firmware from scratch.
Typical applications include industrial control systems, motor drive front-ends, smart sensor nodes, embedded instrumentation, and white-goods appliance controllers. The combination of 33 I/O lines and 4 KB of code storage fits mid-range embedded products where deterministic real-time behavior matters.
When designing with this part, plan for OTP programming: the program memory cannot be erased, so production code must be fully verified before blow. Use the matching windowed ceramic (JW) variant for prototype development, then move to the OTP "P" package for production builds. Microchip recommends migrating to the PIC18F4220 for new designs, but the PIC17C42A-16/P remains a supported legacy option.
Drop-in alternatives for PIC17C42A-16/P — 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 PIC17C42A-16/P (same form factor and footprint) — differing in Package, Mounting Type, Program Memory Type, Core Architecture, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC17C42A-16I/P
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC17C42AT-16I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC17C42A-16/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC17C42A-16/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC17C42A-16/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC17C, 8-bit RISC |
| Instruction Set Size | 58 single-word instructions |
| Maximum Clock Frequency | 16 MHz |
| Performance | 8.25 MIPS (121 ns instruction cycle) |
| Program Memory Type | OTP (One-Time-Programmable) EPROM |
| Program Memory Size | 4 KB (2K x 16) |
| Data RAM | 232 x 8 bytes |
| Digital I/O Pins | 33 |
| Timers | 2 x 8-bit, 2 x 16-bit (4 total) |
| Capture Inputs | 2 |
| PWM Channels | 2 |
| Communication Peripherals | 1 x USART |
| External Oscillator | Yes (crystal/ceramic resonator input) |
| External Memory Addressing | Yes |
| Operating Voltage | 5 V (typical PIC17C range) |
| Operating Temperature | -40C to +85C |
| Package | 40-pin PDIP (P), 0.600" / 15.24 mm body |
| Mounting Type | Through-Hole (DIP) |
| Series | PIC 17C |
| RoHS Status | Compliant (verify per lot) |
PIC17C42A-16/P Pin Configuration
| Pin 1 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 2 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 3 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Pin 4 | RA3/AN3 — PORTA bit 3 / analog input 3 |
| Pin 5 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 6 | RA5/SS — PORTA bit 5 / SPI slave select |
| Pin 7 | OSC1/CLKIN — Crystal oscillator input / external clock in |
| Pin 8 | OSC2/CLKOUT — Crystal oscillator output / clock out |
| Pin 9 | RC0 — PORTC bit 0 |
| Pin 10 | RC1 — PORTC bit 1 |
| Pin 11 | RC2 — PORTC bit 2 |
| Pin 12 | RC3 — PORTC bit 3 |
| Pin 13 | RC4 — PORTC bit 4 |
| Pin 14 | RC5 — PORTC bit 5 |
| Pin 15 | RC6 — PORTC bit 6 |
| Pin 16 | RC7 — PORTC bit 7 |
| Pin 17 | VSS — Ground reference |
| Pin 18 | VDD — Positive supply (5 V) |
| Pin 19 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 20 | RB1 — PORTB bit 1 |
| Pin 21 | RB2 — PORTB bit 2 |
| Pin 22 | RB3 — PORTB bit 3 |
| Pin 23 | RB4 — PORTB bit 4 |
| Pin 24 | RB5 — PORTB bit 5 |
| Pin 25 | RB6 — PORTB bit 6 |
| Pin 26 | RB7 — PORTB bit 7 |
| Pin 27 | RD0 — PORTD bit 0 |
| Pin 28 | RD1 — PORTD bit 1 |
| Pin 29 | RD2 — PORTD bit 2 |
| Pin 30 | RD3 — PORTD bit 3 |
| Pin 31 | RD4 — PORTD bit 4 |
| Pin 32 | RD5 — PORTD bit 5 |
| Pin 33 | RD6 — PORTD bit 6 |
| Pin 34 | RD7 — PORTD bit 7 |
| Pin 35 | RE0/RD — PORTE bit 0 / read control |
| Pin 36 | RE1/WR — PORTE bit 1 / write control |
| Pin 37 | RE2/CS — PORTE bit 2 / chip select |
| Pin 38 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 39 | TX/CK — USART transmit / clock line |
| Pin 40 | RX/DT — USART receive / data line |
Typical Applications
PIC17C42A-16/P is suitable for 6 applications: Industrial Motor Control Front-End, White-Goods Appliance Controller, Embedded Instrumentation and Data Acquisition, Smart Sensor and Transmitter Nodes, Automotive Body Electronics (Legacy 5 V Systems), Educational and Development Boards.
Industrial Motor Control Front-End
The PIC17C42A-16/P fits industrial motor control front-ends thanks to its 33 I/O pins, dual 16-bit timers, dual capture inputs, and dual PWM channels - exactly the peripheral set needed to sense rotor position and drive H-bridge gates. At 16 MHz / 8.25 MIPS the core can sample Hall sensors, compute commutation tables, and update PWM duty every 121 ns instruction cycle, all within a deterministic single-cycle PIC17C pipeline. The 4 KB OTP program space holds state-machine commutation code plus speed-loop PID. The 232-byte RAM is sufficient for a small lookup table, while external memory addressing lets you page larger tables. Pair the PIC17C42A-16/P with gate drivers like the IR2104 or HIP4081A and Hall-effect sensors for a robust 5 V motor controller.
Recommended
White-Goods Appliance Controller
Washing machines, dishwashers, and HVAC controllers use the PIC17C42A-16/P because its 33 I/O can drive seven-segment displays, keypad matrices, relays, and triac interfaces directly without external glue logic. The hardware USART enables connectivity to inverter boards or smart-meter modules, while the two PWM outputs can modulate a buzzer and a valve driver. OTP program memory makes the part attractive for high-volume appliance production where firmware is locked at the factory and unit cost matters. At 8.25 MIPS, the PIC17C42A handles sensor scanning, button debouncing, and safety interlocks comfortably. The 40-pin PDIP package suits wave-soldered appliance PCBs.
Recommended
Embedded Instrumentation and Data Acquisition
Test equipment, panel meters, and sensor-interface boards benefit from the PIC17C42A-16/P's combination of 33 I/O, dual 16-bit timers for precise interval timing, and dual capture inputs for frequency or pulse-width measurements. The USART streams measurement results to a host PC or display at standard baud rates, while the 4 KB OTP program memory holds calibration tables and linearization routines. With 8.25 MIPS throughput the controller can average ADC samples from an external converter, apply scaling, and update a 7-segment or LCD display without visible latency. The industrial -40C to +85C temperature range lets the same board serve factory-floor and outdoor installations.
Recommended
Smart Sensor and Transmitter Nodes
Industrial 4-20 mA transmitters, RTU modules, and smart-sensor signal conditioners fit the PIC17C42A-16/P well: 33 I/O can drive multiple sensor bridges, the USART provides RS-232/RS-485 comms to a fieldbus master, and the 4 KB OTP program memory holds linearization plus HART or Modbus protocol stacks. The PIC17C core's deterministic 121 ns instruction cycle suits tight timing budgets on RTU scan loops. External memory addressing lets the firmware page additional lookup tables for sensor compensation. Pair the MCU with a 16-bit ADC like the MCP3201 for high-accuracy sensor digitization and an RS-485 transceiver such as the MAX485 for fieldbus connectivity.
Recommended
Automotive Body Electronics (Legacy 5 V Systems)
Older 5 V automotive body controllers - window lifts, mirror adjusters, interior lighting, and HVAC blend doors - run on the PIC17C42A-16/P because the 5 V rail matches legacy wiring harnesses and the 33 I/O can drive dozens of relays and H-bridges without mux chips. The two PWM channels modulate seat motors or lamp dimmers, while the dual capture inputs read Hall-effect position sensors. The -40C to +85C industrial temperature range covers cabin environments. For under-hood or AEC-Q100 mandated applications, migrate to a newer PIC18F K-line part; the PIC17C42A is best for non-safety body modules where 5 V and OTP cost are priorities.
Recommended
Educational and Development Boards
Universities and training labs continue to use the PIC17C42A-16/P in PIC architecture courses because the 58-instruction RISC core is easy to teach and the 4 KB OTP program memory forces disciplined code budgeting. The 33 I/O map cleanly onto common lab peripherals - LED arrays, seven-segment displays, keypads, character LCDs, and stepper motors. The USART enables terminal I/O for assembly exercises. Students can prototype on the JW (windowed) ceramic variant, then commit to OTP for the final project board. The 40-pin PDIP package is breadboard-friendly and survives repeated insertion cycles.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C42A-16/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C42A-16I/P | PIC17C42AT-16I/P | PIC17C42A-16/PT | PIC17C42A-16/PQ |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 40-PDIP (P) | 40-PDIP (P) - same | 40-PDIP (P) - same | 40-PDIP (P) - same | 44-PQFP (PQ) - different footprint, NOT pin-compatible with PDIP |
| Core | 8-bit PIC17C RISC | 8-bit PIC17C RISC | 8-bit PIC17C RISC | 8-bit PIC17C RISC | 8-bit PIC17C RISC |
| Max Clock | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz |
| Program Memory | 4 KB OTP | 4 KB OTP | 4 KB OTP | 4 KB OTP | 4 KB OTP |
| Data RAM | 232 bytes | 232 bytes | 232 bytes | 232 bytes | 232 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Operating Temperature | -40C to +85C | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (standard) | -40C to +85C |
| Lifecycle Status | Last-time-buy | Last-time-buy | Last-time-buy | Last-time-buy | Last-time-buy |
Key Differentiators
- Same die, identical silicon across all PIC17C42A temperature grade variants (vs PIC17C42A-16I/P)
- Original Microchip-recommended replacement target (vs PIC18F4220)
- Higher I/O count and dual-PWM peripheral set vs PIC16C family (vs PIC16C55)
Design Notes
OTP program memory cannot be erased. Verify firmware on a JW (windowed ceramic) variant or via software simulator (MPLAB SIM) before committing code to a production OTP PIC17C42A-16/P. Programming the wrong firmware into OTP is permanent and wastes the unit. Always set the configuration bits (oscillator type, watchdog, code protection) explicitly in your programmer template; default unprogrammed values may enable code protection or select the wrong oscillator mode.
Place a 0.1 uF decoupling capacitor as close as possible to the VDD pin (pin 18) with a short, wide trace to the VSS pin (pin 17). Add a bulk 10 uF tantalum or aluminum capacitor on the same 5 V rail. The MCLR/VPP pin (pin 38) needs a 10 kohm pull-up to VDD for normal operation; during programming the programmer drives VPP high (about 13 V) through this pin, so keep the trace short and avoid loading it with capacitance > 100 pF.
Route the OSC1/OSC2 crystal traces (pins 7-8) symmetrically and keep them short, surrounded by a ground guard ring. If using an external canned oscillator, drive only OSC1 and leave OSC2 floating per datasheet DS30412C. Place the crystal within 5 mm of the MCU to minimize stray capacitance and EMI pickup; long crystal traces are a common source of oscillator startup failures on PIC17C designs.
Estimated: at 5 V VDD and 16 MHz clock with all 33 I/O driving CMOS loads, the PIC17C42A-16/P typically draws < 50 mA active and < 5 uA standby. The 40-PDIP package has theta_JA around 50 C/W in still air, so power dissipation is rarely a thermal concern. However, in sealed enclosures above 60 C ambient, verify oscillator stability and consider a ceramic resonator instead of a crystal if drift is unacceptable.
Compliance Information
RoHS and lead-free per Microchip product page; AEC-Q100 not qualified (industrial grade only). Verify halogen-free status per specific lot via manufacturer documentation.
