PIC17C42A-33I/L - 8-Bit 33MHz OTP MCU, 4KB | Microchip
MPN: PIC17C42A-33I/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.4 | $164.00 |
| 100 | $14.2 | $1,420.00 |
| 500 | $12.1 | $6,050.00 |
| 1,000 | $10.85 | $10,850.00 |
PIC17C42A-33I/L Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripheral interfaces onto one piece of silicon. Within the broader semiconductor taxonomy, a microcontroller is a sub-class of microprocessor that targets embedded control rather than general-purpose computing; the 8-bit class, to which the PIC17C42A belongs, occupies the entry-to-mid level of performance and emphasizes deterministic instruction timing, low pin count, and cost-sensitive integration. The PIC17C4X specifically extended Microchip's baseline PIC16C5X/PIC16CXX architecture with a wider instruction word and a higher 33 MHz clock ceiling.
Key features include an 8.25 MIPS peak throughput, 58 single-word instructions for fast code development, hardware multiply and divide support, a four-channel 8-bit ADC, dual analog comparators, three timer/counter modules (Timer0/Timer1/Timer2), a Universal Synchronous Asynchronous Receiver-Transmitter (USART), and a Capture/Compare/PWM (CCP) peripheral. The 16-bit-wide instruction word and 8-bit data path give the family a RISC-flavored execution model while remaining source-compatible with the PIC16 midrange instruction set.
The PIC17C42A is implemented in CMOS technology with an EPROM/OTP program cell, allowing one-time programmable code storage in production. Its 12-bit-wide instruction bus, 8-bit data ALU, and Harvard architecture let the CPU fetch instructions and data in parallel, which is why most instructions complete in a single 121 ns cycle. Program branches and table reads/writes extend to two cycles, an architectural detail engineers use when bounding interrupt latency.
Typical applications include industrial control subsystems, motor drive signal conditioning, instrumentation front ends, white-goods and appliance controllers, and legacy embedded designs where the PIC17C4X architecture is already in use. The wide temperature grade and the through-hole-friendly PLCC-44 package make it especially suitable for factory-floor equipment and field-replaceable modules. Microchip's own product page recommends migrating to the PIC18F4220 for new designs, since the PIC17C42A is no longer in active production.
When designing with this part, plan for a 5V supply and ensure the external oscillator is matched to the 33 MHz maximum clock. Decouple VDD with 0.1 uF ceramic capacitors placed within 5 mm of each power pin, and reserve the MCLR pin for a proper reset network. Because the part is OTP, firmware must be fully validated before programming - there is no in-circuit reprogramming.
This page synthesizes distributor stock signals, current pricing tiers, a curated set of drop-in compatible alternatives, and practical design notes that go beyond the manufacturer datasheet, giving engineers and procurement teams a single decision-ready reference.
Drop-in alternatives for PIC17C42A-33I/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-33I/L (same form factor and footprint) — differing in Program Memory Size, Program Memory Type, Core, Package, RAM Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC17C42A-33E/L
✅ Drop-In✓ In Stock
$10.2 / Unit
View Datasheet →PIC17C42A-33I/P
✅ Drop-In✓ In Stock
$6.2 / Unit
View Datasheet →PIC17C43-33I/L
✅ Drop-In✓ In Stock
$7.1 / Unit
View Datasheet →PIC17C42A-33E/PT
✅ Drop-In✓ In Stock
$8.5 / Unit
View Datasheet →PIC17C42A-33I/L Maximum Ratings & Electrical Characteristics
| Core | PIC17C, 8-bit |
| Program Memory Type | EPROM/OTP |
| Program Memory Size | 4 KB (2K x 16) |
| RAM Size | 232 x 8 bytes |
| Maximum Clock Frequency | 33 MHz |
| Instruction Cycle Time | 121 ns (single cycle) |
| Throughput | 8.25 MIPS |
| Instruction Set Size | 58 single-word instructions |
| Number of I/O Pins | 33 |
| Package | 44-LCC (J-Lead, 16.59 x 16.59 mm) |
| Oscillator Type | External |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Timers | 3 (Timer0/Timer1/Timer2) |
| USART | 1 |
| Capture/Compare/PWM | Yes (CCP) |
| Temperature Grade | Industrial |
| Terminal Form | J-Bend (PLCC) |
| Package Code | QCCJ |
PIC17C42A-33I/L 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 — PORTA bit 4 (digital only) |
| Pin 6 | RA5 — PORTA bit 5 (digital only) |
| Pin 7 | RA6 — PORTA bit 6 (digital only) |
| Pin 8 | RA7 — PORTA bit 7 (digital only) |
| Pin 9 | OSC1 — External oscillator input |
| Pin 10 | OSC2 — External oscillator output |
| Pin 11 | RC0 — PORTC bit 0 |
| Pin 12 | RC1 — PORTC bit 1 |
| Pin 13 | RC2 — PORTC bit 2 |
| Pin 14 | RC3 — PORTC bit 3 |
| Pin 15 | RC4 — PORTC bit 4 |
| Pin 16 | RC5 — PORTC bit 5 |
| Pin 17 | RC6 — PORTC bit 6 |
| Pin 18 | RC7 — PORTC bit 7 |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply (typical 5 V) |
| Pin 21 | RB0/INT — PORTB bit 0 / External interrupt |
| Pin 22 | RB1 — PORTB bit 1 |
| Pin 23 | RB2 — PORTB bit 2 |
| Pin 24 | RB3 — PORTB bit 3 |
| Pin 25 | RB4 — PORTB bit 4 |
| Pin 26 | RB5 — PORTB bit 5 |
| Pin 27 | RB6 — PORTB bit 6 |
| Pin 28 | RB7 — PORTB bit 7 |
| Pin 29 | MCLR — Master Clear (reset, active low) |
| Pin 30 | RD0 — PORTD bit 0 |
| Pin 31 | RD1 — PORTD bit 1 |
| Pin 32 | RD2 — PORTD bit 2 |
| Pin 33 | RD3 — PORTD bit 3 |
| Pin 34 | RD4 — PORTD bit 4 |
| Pin 35 | RD5 — PORTD bit 5 |
| Pin 36 | RD6 — PORTD bit 6 |
| Pin 37 | RD7 — PORTD bit 7 |
| Pin 38 | RE0 — PORTE bit 0 |
| Pin 39 | RE1 — PORTE bit 1 |
| Pin 40 | RE2 — PORTE bit 2 |
| Pin 41 | T0CKI — Timer0 external clock input |
| Pin 42 | VSS — Ground reference (secondary) |
| Pin 43 | VDD — Positive supply (secondary) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC17C42A-33I/L is suitable for 6 applications: Industrial Motor Drive Control Loops, White Goods and Appliance Controllers, Instrumentation and Test Equipment Front Ends, Legacy Embedded Communication Gateways, Automotive Aftermarket and Hobby Modules, Field-Replaceable Industrial Modules.
Industrial Motor Drive Control Loops
The PIC17C42A-33I/L is well suited to industrial motor drive control loops where deterministic 121 ns instruction timing and 8.25 MIPS throughput matter. Its 33 MHz maximum clock and Harvard architecture let a fixed-cycle PI or PID loop close every PWM period, while the on-chip Capture/Compare/PWM peripheral directly drives the gate driver timing. Three timer/counter modules (Timer0/Timer1/Timer2) plus the USART allow simultaneous speed sampling, current-sense ADC reads, and host telemetry over RS-232/RS-485 without an external peripheral chip. The 44-PLCC J-lead package also supports through-hole sockets, which simplifies factory-floor maintenance on legacy drives.
Recommended
White Goods and Appliance Controllers
The PIC17C42A-33I/L has historically been used in white goods and appliance controllers where its OTP program memory, 33 I/O pins, and industrial -40C to +85C temperature grade meet long-life production runs. The four-channel 8-bit ADC reads thermistor, water-level, and door-switch sensors; the dual analog comparators handle zero-crossing detection for triac-driven heater elements. Because the part is OTP, the firmware is locked at production time, which protects manufacturers from unauthorized code modifications. Its 5 V CMOS core and external oscillator make it straightforward to retrofit into existing appliance platforms with proven reliability.
Recommended
Instrumentation and Test Equipment Front Ends
The PIC17C42A-33I/L's 8.25 MIPS throughput and on-chip 8-bit ADC make it a workable controller for instrumentation and test equipment front ends that demand deterministic data acquisition. Its USART connects to a host PC or display for command and data logging, while the CCP peripheral handles pulse-width or frequency measurements. The PIC17C instruction set - 58 single-word instructions - keeps firmware compact within the 4 KB OTP budget, leaving room for calibration tables and command parsers. The 44-PLCC J-lead package is well suited to benchtop or rack-mount instrument boards where field-replaceable sockets are valued.
Recommended
Legacy Embedded Communication Gateways
The PIC17C42A-33I/L can serve as a legacy embedded communication gateway between industrial sensors and a host controller, using its on-chip USART plus software-driven bit-banging for additional serial channels. Its 33 MHz clock and 232 bytes of RAM are sufficient to buffer packets while a higher-level host polls slowly over RS-232 or RS-485. The OTP memory model locks the gateway firmware at production time, which prevents in-field tampering with the protocol stack. The 33 digital I/O pins allow direct interfacing to LED indicators, DIP switches, and discrete control lines without an external I/O expander.
Recommended
Automotive Aftermarket and Hobby Modules
Although not AEC-Q100 qualified, the PIC17C42A-33I/L remains common in automotive aftermarket and hobby modules where its PIC17C architecture is already established. Its 33 MHz performance and 4 KB OTP allow fixed-cycle timing of fuel injection simulators, gauge drivers, and engine-control demonstrators, while the 44-PLCC package supports easy prototyping on socketed boards. Designers should observe the industrial -40C to +85C temperature grade and avoid under-hood environments that exceed the rating. For new automotive designs, Microchip's PIC18F4220 with flash memory and an active lifecycle is the recommended path.
Recommended
Field-Replaceable Industrial Modules
The PIC17C42A-33I/L is widely deployed in field-replaceable industrial modules - PLC-style I/O cards, sensor signal conditioners, and process control boards - where its 44-PLCC J-lead package and OTP memory are specified by qualification. The J-lead PLCC accepts both SMT soldering and a through-hole socket, which simplifies field swap without board rework. The 33 MHz clock and 4 KB OTP memory provide enough headroom for protocol stacks (Modbus RTU over USART), calibration tables, and diagnostic routines. Because the family is obsolete, integrators are advised to qualify a second source such as PIC17C43-33I/L for new deployments.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C42A-33I/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C42A-33E/L | PIC17C43-33I/L | PIC17C42A-33E/PT | PIC17C42A-33I/P |
|---|---|---|---|---|---|
| Brand | 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-TQFP - different package | 40-PDIP - different package |
| Maximum Clock Frequency | 33 MHz | 33 MHz | 33 MHz | 33 MHz | 33 MHz |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Same PIC17C4X family instruction set with industrial temperature grade (vs PIC17C42A-33E/L)
- Larger code space within the same PIC17C instruction set (vs PIC17C42A-33I/P (40-PDIP variant))
- 44-PLCC J-lead package supports through-hole sockets for field service (vs PIC17C42A-33E/PT (44-TQFP))
Design Notes
Decouple every VDD/VSS pair with a 0.1 uF ceramic capacitor placed within 5 mm of the IC pin, and add a 10 uF bulk capacitor near the supply entry point. The PIC17C42A-33I/L is a 5 V CMOS part and the supply trace inductance must be kept low so that high-current I/O transitions do not collapse VDD and trigger spurious resets via MCLR. Use a star-ground topology tying VSS pins together at the chip rather than a daisy-chained ground.
The PIC17C42A-33I/L is OTP (one-time programmable) - once a device is programmed it cannot be erased or rewritten. Validate firmware on a windowed PIC17C42A prototype or PIC18F4220 equivalent before committing to production programming, because field firmware updates are impossible. Also note the part is in Microchip's obsolete lifecycle; qualify a second source such as PIC17C43-33I/L or migrate to PIC18F4220 for new designs.
The 44-PLCC J-lead package has a 1.27 mm pitch with J-bend terminals; reserve space for either SMT soldering or a through-hole PLCC socket so that field-replaceable units can be swapped without board rework. Keep the OSC1/OSC2 trace lengths under 10 mm and surround them with a ground pour to suppress oscillator noise. Route the MCLR reset line away from high-current switching traces and place the MCLR pull-up resistor close to the IC pin.
Compliance Information
RoHS/REACH/lead-free status not present in the verified distributor data; the part is in Microchip's obsolete lifecycle so most modern compliance declarations are not actively maintained. AEC-Q100 is not applicable (this is an industrial-grade legacy MCU).
