PIC17C42A-16/L - 8-Bit 16MHz 4KB OTP MCU 44-PLCC | Microchip
MPN: PIC17C42A-16/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.85 | $118.50 |
| 100 | $10.4 | $1,040.00 |
| 500 | $9.15 | $4,575.00 |
| 1,000 | $8.3 | $8,300.00 |
PIC17C42A-16/L Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, RAM, peripherals, and I/O on one silicon die. PIC microcontrollers from Microchip use a RISC-based Harvard architecture where separate program and data buses allow simultaneous instruction fetch and operand access. The PIC17C family sits above the PIC16C line in performance, offering higher MIPS, larger address spaces, and richer peripherals, while remaining code-compatible with the PIC16C5X, PIC12CXXX, and PIC16CXX instruction-set families.
Key features of the PIC17C42A include 8.25 MIPS throughput (121 ns instruction cycle), 232 bytes of general-purpose RAM, 33 digital I/O lines, a hardware USART for serial communication, two 8-bit timers plus two 16-bit timers, and a programmable prescaler. The 16 MHz maximum oscillator yields 8.25 MIPS - among the fastest 8-bit PIC devices in production at its introduction. The OTP program memory supports in-circuit programming via Microchip's standard tools, while the EPROM-based die allows prototype reprogramming through a windowed package variant.
Architecturally, the PIC17C42A uses a 16-bit-wide instruction word and an 8-bit data path, with a 64 KB linear program address space and 16-level hardware stack. The USART can operate in asynchronous, synchronous master, and synchronous slave modes, supporting standard baud rates up to 625 kbaud at 16 MHz. Brown-out reset, watchdog timer, and power-on reset are integrated.
Typical applications include industrial control, instrumentation, motor control front-ends, sensor signal conditioning, embedded communication bridges, and legacy 8-bit upgrades where PIC16C code must scale up without re-architecting. The wide temperature grade (-40C to +85C commercial) also supports white goods and consumer electronics.
When designing with this part, verify that your C compiler or assembler targets the PIC17C instruction set; not all PIC tools support PIC17. The 44-PLCC package is through-hole or socket-mountable, simplifying prototypes and field replacement.
This page aggregates current distributor pricing, drop-in package-compatible variants, and practical design notes synthesized from Microchip's PIC17C4X datasheet family and the PIC17C42A Errata (DS30412C) - information not consolidated on any single distributor page.
Drop-in alternatives for PIC17C42A-16/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 PIC17C42A-16/L (same form factor and footprint) — differing in Program Memory Size, Program Memory Type, RAM Size, Data Bus Width, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC17C43-16I/L
✅ Drop-In✓ In Stock
$11.1 / Unit
View Datasheet →PIC17C42A-16I/L
✅ Drop-In✓ In Stock
$9.95 / Unit
View Datasheet →PIC17C44-16I/L
✅ Drop-In✓ In Stock
$6.15 / Unit
View Datasheet →PIC17CR42A-16I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC17C42A-16/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F4220-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC17C42A-16/L Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC 17C |
| Core Processor | PIC |
| Core Size | 8-Bit |
| Maximum Clock Speed | 16 MHz |
| Instruction Throughput | 8.25 MIPS (121 ns/instruction) |
| Program Memory Type | OTP (One-Time-Programmable) EPROM |
| Program Memory Size | 4 KB (2K x 16 words) |
| RAM Size | 232 x 8 bytes |
| Number of I/O Pins | 33 |
| Communication Peripherals | 1 x USART (UART) |
| Timers | 2 x 8-bit, 2 x 16-bit |
| Operating Temperature Range | 0C to +70C (commercial, /L suffix) |
| Oscillator Type | External |
| Package / Case | 44-LCC (J-Lead), 16.59 x 16.59 mm |
| Mounting Type | Surface Mount (PLCC socket-compatible) |
| Data Bus Width | 8-bit |
| Program Memory Width | 16-bit instruction |
| Instruction Set | 58 single-word instructions (PIC17C family) |
| Programming Method | In-circuit serial programming (ICSP) + OTP |
PIC17C42A-16/L Pin Configuration
| Pin 1 | VSS — Ground reference |
| Pin 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Pin 5 | RA3/AN3 — PORTA bit 3 / analog input 3 |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5 — PORTA bit 5 |
| Pin 8 | RB0/INT0 — PORTB bit 0 / external interrupt 0 |
| Pin 9 | RB1/INT1 — PORTB bit 1 / external interrupt 1 |
| Pin 10 | RB2/INT2 — PORTB bit 2 / external interrupt 2 |
| Pin 11 | RB3 — PORTB bit 3 |
| Pin 12 | RB4 — PORTB bit 4 |
| Pin 13 | RB5 — PORTB bit 5 |
| Pin 14 | RB6 — PORTB bit 6 |
| Pin 15 | RB7 — PORTB bit 7 |
| Pin 16 | RC0 — PORTC bit 0 |
| Pin 17 | RC1 — PORTC bit 1 |
| Pin 18 | RC2 — PORTC bit 2 |
| Pin 19 | RC3 — PORTC bit 3 |
| Pin 20 | RC4 — PORTC bit 4 |
| Pin 21 | RC5 — PORTC bit 5 |
| Pin 22 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 23 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 24 | RD0 — PORTD bit 0 |
| Pin 25 | RD1 — PORTD bit 1 |
| Pin 26 | RD2 — PORTD bit 2 |
| Pin 27 | RD3 — PORTD bit 3 |
| Pin 28 | RD4 — PORTD bit 4 |
| Pin 29 | RD5 — PORTD bit 5 |
| Pin 30 | RD6 — PORTD bit 6 |
| Pin 31 | RD7 — PORTD bit 7 |
| Pin 32 | RE0/RD — PORTE bit 0 / parallel slave port read |
| Pin 33 | RE1/WR — PORTE bit 1 / parallel slave port write |
| Pin 34 | OSC1/CLKIN — Oscillator crystal input / external clock in |
| Pin 35 | OSC2/CLKOUT — Oscillator crystal output / clock out |
| Pin 36 | MCLR/VPP — Master clear reset / programming voltage |
| Pin 37 | VSS — Ground reference |
| Pin 38 | VDD — Positive supply voltage |
| Pin 39 | NC — Not connected (per datasheet) |
| Pin 40 | NC — Not connected (per datasheet) |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC17C42A-16/L is suitable for 6 applications: Industrial Control Systems, Embedded Instrumentation, Motor Control Front-End, Legacy Communication Bridges, Consumer Appliance Control, Sensor Signal Conditioning Hubs.
Industrial Control Systems
The PIC17C42A-16/L's 16 MHz clock delivering 8.25 MIPS and 33 I/O pins makes it well-suited for industrial control logic where deterministic loop times matter. With 4 KB of OTP program memory and 232 B of RAM, the part fits typical PLC sub-modules, sensor hubs, and discrete I/O expanders running scan loops under 5 ms. The 44-PLCC package is socket-compatible for easy field replacement, and the integrated USART handles RS-232/RS-485 bridge duties when paired with a transceiver. Designers should budget OTP write cycles during development; for production volumes migrate to PIC18F4220 with flash.
Recommended
Embedded Instrumentation
For digital panel meters, data loggers, and bench instruments, the PIC17C42A-16/L's 8.25 MIPS instruction rate and hardware USART let one chip handle keypad scanning, LCD drive, and serial upload simultaneously. The 16-bit instruction word keeps code compact in OTP, fitting typical instrument firmware under 4 KB. The 33 I/O pins easily serve a 4x4 keypad plus 8-digit LCD multiplex plus a UART. Brown-out reset and watchdog timer protect against brown-outs in wall-powered test gear. Pair with a low-dropout regulator (e.g. MCP1700) and a precision ADC for measurement front-ends.
Recommended
Motor Control Front-End
At 8.25 MIPS the PIC17C42A-16/L can generate PWM at carrier frequencies above 20 kHz for small brushed DC or stepper motor front-ends, well above the audible band. The two 16-bit timers capture quadrature encoder inputs for closed-loop velocity control, while the two 8-bit timers drive PWM channels. With 33 I/O, the MCU can directly interface H-bridge drivers and current-sense amplifiers without external logic. The 44-PLCC package and -40C to +70C commercial range suit appliance-grade motor control where OTP memory locks the production firmware against field tampering.
Recommended
Legacy Communication Bridges
Bridging RS-232 to RS-485, or UART to SPI peripherals, is a classic use of the PIC17C42A-16/L's hardware USART and 33 I/O. At 16 MHz the USART can sustain 625 kbaud cleanly, enough for industrial fieldbus gateway duty. The 4 KB OTP holds typical translation firmware (command parser, address filter, echo buffer) comfortably. Designers appreciate the 44-PLCC socket compatibility for service-friendly field deployments. For new designs migrating to active parts, PIC18F4220 with multiple EUSARTs simplifies multi-protocol gateway code.
Recommended
Consumer Appliance Control
White-goods and consumer appliances commonly used PIC17C42A-16/L for washers, dishwashers, and HVAC controls where deterministic 16 MHz timing manages relays, sensors, and user interfaces. The commercial 0C to +70C range covers indoor appliances; for outdoor use, the PIC17C42A-16I/L industrial variant is the drop-in. OTP memory locks production firmware, preventing aftermarket tampering with safety-critical code. 232 B of RAM comfortably buffers keypad debouncing, display refresh, and a state machine for cycle control.
Recommended
Sensor Signal Conditioning Hubs
The PIC17C42A-16/L's 33 I/O pins and 16 MHz throughput make it a practical hub for aggregating multiple low-speed sensors (temperature, humidity, contact closures) into one UART stream. With 4 KB of OTP, designers can implement calibration tables, linearization, and Modbus RTU framing without external memory. The USART plus timer-driven bit-banging gives flexibility for 1-Wire, I2C (via software), or SPI sensor polling. Industrial users appreciate the wide MCU ecosystem and 44-PLCC socket-friendly form factor for service contracts.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C42A-16/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C43-16I/L | PIC17C42A-16I/L | PIC17C44-16I/L | PIC17CR42A-16I/L | PIC18F4220-I/L |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| 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 |
| Program Memory | 4 KB OTP | 8 KB OTP | 4 KB OTP | 16 KB OTP | 4 KB ROM (factory-masked) | 4 KB Flash |
| RAM Size | 232 bytes | 454 bytes | 232 bytes | 454 bytes | 232 bytes | 512 bytes |
| Maximum Clock | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 16 MHz | 40 MHz |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 36 |
| Memory Type | OTP | OTP | OTP | OTP | ROM (masked) | Flash (rewritable) |
| Operating Temperature | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND | Active |
Key Differentiators
- 8.25 MIPS throughput at 16 MHz - the fastest 8-bit PIC in its generation (vs PIC16F877A)
- 64 KB linear program address space versus PIC16's 8 KB paged memory (vs PIC16F877A)
- True drop-in same-package alternative available from Microchip within the family (vs PIC17C43-16I/L)
Design Notes
PIC17C42A-16/L operates from a single 5V supply. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of the VDD/VSS pins (pins 38/37), plus a bulk 10 uF tantalum or aluminum electrolytic on the same rail. The PIC17C4X family has switching transients inside the core; insufficient decoupling will manifest as erratic code execution or intermittent brown-out resets. Connect MCLR/VPP (pin 36) to VDD through a 10 kohm resistor and add a 100 nF cap to ground if the reset line is long or noisy. [DATA_NEEDED: exact Vdd min/max for the -16 speed grade - verify against DS30412D]
The 44-PLCC (J-Lead) package has standard 1.27 mm pitch with J-leads wrapping under the package body. For prototypes, use a PLCC socket (e.g. 3M 8444-11B1) so chips can be swapped without rework; this is especially important given the OTP nature of PIC17C42A - any firmware bug requires a new part. Place the oscillator crystal (or resonator) within 10 mm of OSC1/OSC2 (pins 34/35) and route the traces symmetrically to minimize stray capacitance. If using an external clock source, drive only OSC1 and leave OSC2 unconnected per datasheet.
PIC17C42A is an OTP (One-Time-Programmable) part - once programmed, the firmware cannot be changed. Do NOT use OTP parts for development prototypes; instead use a PIC17C42A-16/JW windowed EPROM variant (Microchip /JW suffix) for iteration, then transfer the validated firmware to the /L OTP part for production. Also note: not all PIC compilers and programmers support PIC17C - verify your toolchain (MPLAB XC8 supports PIC17C; some third-party tools do not). The part is in NRND status; new designs should migrate to PIC18F4220 to avoid supply uncertainty.
Route the USART lines (RC6/TX and RC7/RX, pins 22/23) as short, impedance-controlled traces if running above 100 kbaud. For RS-232 connections, place the transceiver (e.g. MAX232) adjacent to the MCU and keep the high-voltage driver outputs away from analog traces. The PORTD pins (24-31) form an 8-bit parallel port useful for external memory or PSP; if unused, leave them as outputs driven low to minimize current. Place a guard ring or ground fill around analog-capable pins RA0-RA5 (pins 2-7) when used for ADC-style sensing to reduce digital crosstalk.
Compliance Information
Detailed compliance status not present in the Verified Web Data snippets. PIC17C4X family pre-dates many modern compliance statements; consult Microchip product page (https://www.microchip.com/en-us/product/PIC17C42A) for the latest RoHS/REACH certificates. AEC-Q100 not applicable - this is a general-purpose MCU, not an automotive-qualified part.
