PIC17LC42A-08I/P - 8-bit 33MHz 4KB OTP MCU, 33 I/O DIP-40
MPN: PIC17LC42A-08I/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.51 | $5.51 |
| 10 | $4.78 | $47.80 |
| 100 | $4.35 | $435.00 |
| 500 | $4.05 | $2,025.00 |
| 1,000 | $3.75 | $3,750.00 |
PIC17LC42A-08I/P Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory (ROM/EPROM/Flash), data RAM, and peripherals on one die. The PIC17C family is Microchip's original high-performance 8-bit tier above the baseline PIC16C line, introducing a wider 16-bit instruction word, a hardware multiply, and an expanded peripheral set. In the taxonomy of electronic components, the PIC17LC42A sits within microcontrollers -> 8-bit microcontrollers -> PIC microcontrollers -> PIC17C family -> OTP EPROM-based MCUs.
Key features include 58 single-word instructions, single-cycle execution for most instructions (with two-cycle program branches and table reads/writes), an external oscillator interface, an industrial temperature grade (-40C to +85C), and an instruction set optimized for C-language efficiency. The wide 16-bit instruction word enables a single-cycle hardware multiply and a richer addressing mode set compared to PIC16C baseline parts, allowing higher code density and faster arithmetic.
The PIC17LC42A uses a Harvard architecture with separate program and data buses, OTP EPROM program memory, and an external oscillator input. With a 33 MHz clock and 121 ns instruction cycle, it delivers roughly 8 MIPS throughput, and the 33 I/O lines share four 8-bit ports plus a control port for interrupt, timer, and peripheral functions. The architecture supports 16-bit instructions for code efficiency and offers a richer peripheral set than the PIC16C family.
Typical applications include industrial control systems, motor control front-ends, automotive body electronics (legacy), instrumentation, and embedded control subsystems where through-hole PCB construction and a long-lifecycle 8-bit MCU simplify manufacturing. The wide operating voltage and OTP EPROM also make it attractive for prototyping and short-to-medium production runs.
When designing with this device, plan for an external oscillator and verify that the OTP windowless package is appropriate (JW package required for prototype erasing). The through-hole DIP-40 footprint simplifies hand prototyping but consumes significant board area; consider PIC17C42A variants in surface-mount packages for volume production.
This page synthesizes Microchip PIC17C42A datasheet specifications, DigiKey/Mouser distributor pricing, drop-in same-package alternatives from the PIC17C42A family, and practical design notes that complement the manufacturer datasheet.
Drop-in alternatives for PIC17LC42A-08I/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 PIC17LC42A-08I/P (same form factor and footprint) — differing in Package, Core Architecture, Operating Temperature Range, Mounting Type, Maximum Clock Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC17C42A-16/P
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.45 / Unit
View Datasheet →PIC17C42A-33I/P
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$6.2 / Unit
View Datasheet →PIC17C42A-33/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$9.65 / Unit
View Datasheet →PIC17C42A-25/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.55 / Unit
View Datasheet →PIC17C42A-25E/P
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.6 / Unit
View Datasheet →PIC17C42A-16E/P
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.85 / Unit
View Datasheet →PIC17LC42A-08I/P Maximum Ratings & Electrical Characteristics
| Program Memory Size | 4 KB (2K x 16) OTP EPROM |
| RAM Size | 232 x 8 bytes |
| Number of I/O Pins | 33 |
| Maximum Clock Frequency | 33 MHz |
| Instruction Cycle | 121 ns |
| Core Architecture | 8-bit RISC, Harvard |
| Instruction Set | 58 single-word instructions |
| Oscillator Type | External |
| Program Memory Technology | OTP EPROM |
| Package | 40-PDIP (0.600 in / 15.24 mm) |
| Mounting Type | Through-Hole |
| Operating Temperature Grade | Industrial |
| Operating Temperature Range | -40C to +85C |
| Pin Count | 40 |
| Data EEPROM | None |
| RoHS Status | Compliant |
PIC17LC42A-08I/P Pin Configuration
| Pin 1 | RA0/AN0 — Port A bit 0 / Analog input 0 |
| Pin 2 | RA1/AN1 — Port A bit 1 / Analog input 1 |
| Pin 3 | RA2/AN2 — Port A bit 2 / Analog input 2 |
| Pin 4 | RA3/AN3 — Port A bit 3 / Analog input 3 |
| Pin 5 | RA4/AN4 — Port A bit 4 / Analog input 4 |
| Pin 6 | RA5/AN5 — Port A bit 5 / Analog input 5 |
| Pin 7 | RA6/AN6 — Port A bit 6 / Analog input 6 |
| Pin 8 | RA7/AN7 — Port A bit 7 / Analog input 7 |
| Pin 9 | RB0/INT — Port B bit 0 / External interrupt |
| Pin 10 | RB1 — Port B bit 1 |
| Pin 11 | RB2 — Port B bit 2 |
| Pin 12 | RB3 — Port B bit 3 |
| Pin 13 | RB4 — Port B bit 4 |
| Pin 14 | RB5 — Port B bit 5 |
| Pin 15 | RB6 — Port B bit 6 |
| Pin 16 | RB7 — Port B bit 7 |
| Pin 17 | VSS — Ground |
| Pin 18 | VDD — Positive supply voltage |
| Pin 19 | OSC1/CLKIN — Oscillator input / clock in |
| Pin 20 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 21 | RC0/T1OSO — Port C bit 0 / Timer1 oscillator output |
| Pin 22 | RC1/T1OSI — Port C bit 1 / Timer1 oscillator input |
| Pin 23 | RC2/CCP1 — Port C bit 2 / Capture/Compare/PWM 1 |
| Pin 24 | RC3 — Port C bit 3 |
| Pin 25 | RC4 — Port C bit 4 |
| Pin 26 | RC5 — Port C bit 5 |
| Pin 27 | RC6/TX — Port C bit 6 / USART transmit |
| Pin 28 | RC7/RX — Port C bit 7 / USART receive |
| Pin 29 | RD0 — Port D bit 0 |
| Pin 30 | RD1 — Port D bit 1 |
| Pin 31 | RD2 — Port D bit 2 |
| Pin 32 | RD3 — Port D bit 3 |
| Pin 33 | RD4 — Port D bit 4 |
| Pin 34 | RD5 — Port D bit 5 |
| Pin 35 | RD6 — Port D bit 6 |
| Pin 36 | RD7 — Port D bit 7 |
| Pin 37 | RE0/PSP0 — Port E bit 0 / Parallel Slave Port |
| Pin 38 | RE1/PSP1 — Port E bit 1 / Parallel Slave Port |
| Pin 39 | MCLR/VPP — Master clear reset / Programming voltage |
| Pin 40 | VDD — Positive supply voltage (second pin) |
Typical Applications
PIC17LC42A-08I/P is suitable for 6 applications: Industrial Control Systems, Legacy Automotive Body Electronics, Motor Drive Front-End, Instrumentation and Data Acquisition, Embedded Control Subsystems, Prototype and Educational Platforms.
Industrial Control Systems
The PIC17LC42A-08I/P fits legacy industrial control systems where the proven PIC17C instruction set and through-hole 40-pin PDIP simplify field servicing and hand rework. Its 33 MHz clock, 4KB OTP EPROM, and 33 I/O lines deliver enough throughput for relay sequencing, sensor multiplexing, and simple PID loops. Industrial temperature grade (-40C to +85C) tolerates factory floor environments. The OTP EPROM is ideal for fixed-function controllers; for modernizing, migrate to PIC18F or dsPIC33.
Recommended
Legacy Automotive Body Electronics
The PIC17LC42A-08I/P can replace aging PIC17C42A devices in legacy automotive body modules - door locks, seat controllers, wiper logic, and HVAC actuators. Its 33 I/O pins cover the typical signal count for body controllers, and the industrial temperature grade spans the automotive underhood range. The OTP EPROM locks the calibration per vehicle, and the 40-pin PDIP aids service replacement. For new automotive designs, choose AEC-Q100-qualified dsPIC33 or PIC18F-Q1 parts.
Recommended
Motor Drive Front-End
Use PIC17LC42A-08I/P as the control front-end for low-cost brushed DC or stepper motor drives where the MCU generates PWM, monitors current sensors, and runs commutation logic. The 33 I/O lines handle PWM channels, H-bridge enables, encoder inputs, and fault feedback. 4KB OTP holds typical trapezoidal commutation tables and PI controller constants. Migration to DSPIC33EP64MC204 delivers center-aligned PWM and 14-bit ADC at similar cost for new designs.
Recommended
Instrumentation and Data Acquisition
The PIC17LC42A-08I/P supports instrumentation front-ends that multiplex analog sensors, drive LCD or LED displays, and serialize readings over UART/SPI. With 33 I/O pins, the MCU can scan a keypad, drive a character LCD, and stream data via RS-232 without external glue logic. OTP EPROM holds calibration constants, and the 8 MHz clock is adequate for slow multiplexed measurements. Use the PIC18F4550 for USB-equipped modern replacements.
Recommended
Embedded Control Subsystems
Drop the PIC17LC42A-08I/P into embedded subsystems that require deterministic 8-bit control, such as appliance controllers, vending machines, and HVAC damper actuators. Its 58 single-word instructions and 121 ns cycle time deliver predictable latency for real-time loops. The through-hole 40-pin PDIP aids hand-prototype builds and field rework. The DIP-40 footprint and PIC17C instruction set keep firmware portable across PIC17C42A speed grades for volume flexibility.
Recommended
Prototype and Educational Platforms
The PIC17LC42A-08I/P serves educational labs and engineering prototypes where students learn the PIC17C architecture's 16-bit instruction word, hardware multiply, and external oscillator design. Through-hole 40-pin PDIP packages plug into standard breadboards and development boards. Use the JW (windowed) variant of PIC17C42A for erasable prototypes, since the PIC17LC42A-08I/P is OTP and cannot be re-programmed. Migrate to PIC18F or dsPIC33 for modern curricula.
Recommended
Recommended Products Summary
Engineering reference data for PIC17LC42A-08I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C42A-16/P | PIC17C42A-33I/P | PIC17C42A-33/P | PIC17C42A-25/P |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 40-PDIP (0.600 in) | 40-PDIP - same | 40-PDIP - same | 40-PDIP - same | 40-PDIP - same |
| Maximum Clock Frequency | 8 MHz (33 MHz max spec, -08 suffix denotes 8 MHz rating) | 16 MHz | 33 MHz | 33 MHz | 25 MHz |
| Program Memory | 4 KB (2K x 16) OTP EPROM | 4 KB OTP EPROM - same | 4 KB OTP EPROM - same | 4 KB OTP EPROM - same | 4 KB OTP EPROM - same |
| RAM Size | 232 bytes | 232 bytes - same | 232 bytes - same | 232 bytes - same | 232 bytes - same |
| Number of I/O Pins | 33 | 33 - same | 33 - same | 33 - same | 33 - same |
| Operating Temperature Grade | Industrial (-40C to +85C) | Commercial (0 to +70C) | Industrial - same | Commercial | Commercial |
| Voltage Class | LC (low-voltage) variant | Standard 5V | Standard 5V | Standard 5V | Standard 5V |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Low-voltage (LC) operation versus standard PIC17C42A (vs PIC17C42A-33I/P)
- Industrial temperature grade versus commercial PIC17C42A variants (vs PIC17C42A-33/P)
- Through-hole DIP-40 footprint versus surface-mount PIC17C42A variants (vs PIC17C42A-33I/PT)
Design Notes
The PIC17LC42A-08I/P uses OTP (One-Time-Programmable) EPROM that cannot be erased after programming. Do NOT use this part for prototypes - use the PIC17C42A-16/JW or PIC17C42A-25/JW windowed ceramic package for development, then commit the final code to the OTP PIC17LC42A-08I/P for production. Attempting to re-program the OTP device will destroy the existing code with no recovery.
The PIC17LC42A (low-voltage 'LC' variant) requires careful decoupling - place a 0.1 uF ceramic capacitor directly across VDD and VSS pins (pins 18 and 17), as close to the package as possible. Add a bulk 10 uF tantalum or electrolytic capacitor at the board power entry. Brown-out detection should be enabled via configuration bits to prevent code corruption during supply droop, which can latch up the EPROM control logic and require a full power cycle.
The 40-pin PDIP footprint (0.600 in / 15.24 mm row spacing) simplifies through-hole prototyping but consumes significant board area versus surface-mount alternatives. For production volume, migrate to the PIC17C42A-33/PT (44-TQFP) variant. Layout the MCLR/VPP pin (pin 39) with a 10 kohm pull-up to VDD and a 100 nF cap to ground for clean reset behavior. Place the oscillator (pins 19/20) traces short and shield from switching signals.
PIC17C family oscillator design is sensitive to parasitic capacitance - keep the crystal or ceramic resonator traces (OSC1/OSC2, pins 19 and 20) within 0.5 inch of the package and surround them with a ground pour. For an external CMOS clock input, drive OSC1 directly and leave OSC2 floating per Microchip AN588. Add a series resistor on MCLR if the reset line is long to limit inrush current on power-up.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - this is a legacy industrial-grade part, not automotive. For automotive, choose PIC18F-Q1 or dsPIC33 AEC-Q100 qualified variants.
