PIC17C42AT-33E/L - 33MHz 8-Bit OTP MCU, 4KB, 44-PLCC | Microchip
MPN: PIC17C42AT-33E/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $13.2 | $132.00 |
| 100 | $11.85 | $1,185.00 |
| 500 | $10.6 | $5,300.00 |
| 1,000 | $9.45 | $9,450.00 |
PIC17C42AT-33E/L Overview
An 8-bit microcontroller (MCU) is a microprocessor optimized for embedded control, integrating CPU, RAM, non-volatile program memory, peripherals, and I/O on a single die. Within the embedded hierarchy, the PIC17C42A belongs to the microcontroller category, then to the 8-bit MCU sub-class, then to the OTP-programmed ROM family, then to the high-performance C-variant of the PIC17 series that bridges PIC16 mid-range and PIC18 architectures. OTP parts are programmed once by the user with a device programmer and are widely used for low- to medium-volume production where mask-ROM economics are not justified.
Key specifications include 33 MHz maximum clock frequency, 4 KB (2K x 16) OTP program memory, 232 bytes of RAM, 33 digital I/O lines, hardware UART/USART, an external oscillator interface, and an industrial -40C to +125C operating temperature range (the -33E speed/temperature suffix). The wide operating range makes the part suited to industrial, automotive aftermarket, and harsh-environment applications. Brown-out and watchdog features are typical of the PIC17C42A silicon family.
The PIC17C42A silicon uses an enhanced 8-bit RISC architecture with a 16-bit-wide instruction word and a 16-bit program counter, providing higher code density and faster interrupt response than earlier PIC16 parts. The OTP EPROM cell is verified at the factory for program retention; the wide PLCC package gives generous ground and power pins for noise immunity in motor and power-conversion environments.
Typical applications include industrial automation controllers, motor-control front-ends, UART-connected sensor hubs, security and access-control boards, and embedded communication bridges where a legacy 8-bit architecture, long-life OTP, and 5V-tolerant I/O are required. It is also used in instrumentation front-ends, white-goods control boards, and legacy field-replacement boards.
When designing with this device, ensure the system clock source meets the 33 MHz DC and AC specifications and that decoupling is placed within 5 mm of every VDD/VSS pin pair. Use Microchip's MPLAB and MPASM/SRCP toolchain for code development, and verify OTP programming margin with the recommended algorithm in the device programming specification.
This page synthesizes distributor pricing, drop-in PIC17C42A family alternatives, and practical design notes that go beyond the bare manufacturer datasheet.
Drop-in alternatives for PIC17C42AT-33E/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 PIC17C42AT-33E/L (same form factor and footprint) — differing in Program Memory Size, Program Memory Type, Core Architecture, Operating Temperature, Package.
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/L
✅ Drop-In✓ In Stock
$10.85 / Unit
View Datasheet →PIC17C42AT-33I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC17C42AT-25E/L
✅ Drop-In✓ In Stock
$6.45 / Unit
View Datasheet →PIC17C42AT-25/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$10.5 / Unit
View Datasheet →PIC17C42AT-25/PQ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$8.65 / Unit
View Datasheet →PIC17C42AT-33E/L Maximum Ratings & Electrical Characteristics
| Product Family | PIC17C |
| Core | 8-bit PIC RISC |
| Series | PIC17C42A |
| Maximum Clock Frequency | 33 MHz |
| Program Memory Size | 4 KB (2K x 16) OTP EPROM |
| RAM Size | 232 x 8 bytes (232 B) |
| Number of I/O Pins | 33 |
| Communication Interfaces | UART/USART |
| Oscillator Type | External |
| Package / Case | 44-PLCC (J-Lead), 16.59 x 16.59 mm |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +125C (industrial, -E suffix) |
| Speed Grade | 33 MHz / 33 MIPS (-33 suffix) |
| Program Memory Type | OTP EPROM |
| Packaging | Tape & Reel (TR) |
| Data EEPROM | Not present (OTP part, no data EEPROM) |
PIC17C42AT-33E/L Pin Configuration
| Pin 1 | RA0 — PORTA bit 0 (digital I/O) |
| Pin 2 | RA1 — PORTA bit 1 (digital I/O) |
| Pin 3 | RA2 — PORTA bit 2 (digital I/O) |
| Pin 4 | RA3 — PORTA bit 3 (digital I/O) |
| Pin 5 | RA4 — PORTA bit 4 (digital I/O) |
| Pin 6 | RA5 — PORTA bit 5 (digital I/O) |
| Pin 7 | RA6 — PORTA bit 6 (digital I/O) |
| Pin 8 | RA7 — PORTA bit 7 (digital I/O) |
| Pin 9 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 10 | RB1 — PORTB bit 1 (digital I/O) |
| Pin 11 | RB2 — PORTB bit 2 (digital I/O) |
| Pin 12 | RB3 — PORTB bit 3 (digital I/O) |
| Pin 13 | RB4 — PORTB bit 4 (digital I/O) |
| Pin 14 | RB5 — PORTB bit 5 (digital I/O) |
| Pin 15 | RB6 — PORTB bit 6 (digital I/O) |
| Pin 16 | RB7 — PORTB bit 7 (digital I/O) |
| Pin 17 | RC0 — PORTC bit 0 (digital I/O) |
| Pin 18 | RC1 — PORTC bit 1 (digital I/O) |
| Pin 19 | RC2 — PORTC bit 2 (digital I/O) |
| Pin 20 | RC3 — PORTC bit 3 (digital I/O) |
| Pin 21 | RC4 — PORTC bit 4 (digital I/O) |
| Pin 22 | RC5 — PORTC bit 5 (digital I/O) |
| Pin 23 | RC6 — PORTC bit 6 (digital I/O) |
| Pin 24 | RC7 — PORTC bit 7 (digital I/O) |
| Pin 25 | RD0 — PORTD bit 0 (digital I/O) |
| Pin 26 | RD1 — PORTD bit 1 (digital I/O) |
| Pin 27 | RD2 — PORTD bit 2 (digital I/O) |
| Pin 28 | RD3 — PORTD bit 3 (digital I/O) |
| Pin 29 | RD4 — PORTD bit 4 (digital I/O) |
| Pin 30 | RD5 — PORTD bit 5 (digital I/O) |
| Pin 31 | RD6 — PORTD bit 6 (digital I/O) |
| Pin 32 | RD7 — PORTD bit 7 (digital I/O) |
| Pin 33 | RE0 — PORTE bit 0 (digital I/O) |
| Pin 34 | RE1 — PORTE bit 1 (digital I/O) |
| Pin 35 | RE2 — PORTE bit 2 (digital I/O) |
| Pin 36 | OSC1 — External oscillator input |
| Pin 37 | OSC2 — External oscillator output |
| Pin 38 | MCLR — Master clear (reset) input |
| Pin 39 | VDD — Positive supply voltage |
| Pin 40 | VSS — Ground reference |
| Pin 41 | TX — UART transmit output |
| Pin 42 | RX — UART receive input |
| Pin 43 | VSS — Ground reference |
| Pin 44 | VDD — Positive supply voltage |
Typical Applications
PIC17C42AT-33E/L is suitable for 6 applications: Industrial Automation Controllers, Motor Control Front-Ends, UART Sensor Hubs, Security & Access Control Panels, White Goods Control Boards, Instrumentation Front-Ends.
Industrial Automation Controllers
The PIC17C42AT-33E/L suits legacy industrial automation controllers with its 33 MHz CPU, 232 B RAM, and 33 GPIO that drive relays, opto-isolators, and discrete sensors. The UART/USART peripheral connects to Modbus RTU slave transceivers (e.g. MAX485, ADM2483) for RS-485 fieldbus communication. The 44-PLCC J-Lead package provides mechanical robustness for through-hole-style PCB assemblies common in industrial control cabinets. The -40C to +125C industrial temperature grade supports placement near motors and heaters where ambient swings are large.
Recommended
Motor Control Front-Ends
The PIC17C42AT-33E/L provides PWM and timing capability via its CCP module and 33 MIPS throughput for brushed-DC and stepper motor control front-ends. Its 33 GPIO can be multiplexed to drive H-bridge gate drivers, sense motor current via ADCs, and read Hall-effect sensors. The 4 KB OTP program memory holds state machines, ramp profiles, and fault-recovery routines for small pump, fan, and valve actuators. Industrial -40C to +125C operation ensures reliability near motor heat sources.
Recommended
UART Sensor Hubs
The PIC17C42AT-33E/L functions as a UART sensor hub that aggregates serial data from multiple digital sensors and forwards packets over a higher-level bus. The hardware UART/USART handles framing, parity, and baud-rate generation without software overhead, freeing the 33 MIPS CPU for sensor polling and data conditioning. With 232 B RAM, the part can buffer short telemetry frames. Typical deployments include environmental sensor arrays, GPS/NMEA bridges, and security panel interfaces.
Recommended
Security & Access Control Panels
The PIC17C42AT-33E/L is well suited to security alarm panels, key-card readers, and access-control boards because of its 33 GPIO for keypads, LEDs, buzzer drivers, and relay outputs. OTP memory prevents post-deployment firmware tampering, an advantage for security deployments. The UART/USART links to downstream card readers and central monitoring receivers. Wide temperature tolerance allows outdoor and unheated vestibule installations.
Recommended
White Goods Control Boards
The PIC17C42AT-33E/L is used in washing-machine, dishwasher, and oven control boards where cost-optimized 8-bit MCUs, 5V-tolerant I/O, and proven OTP code retention matter. 33 GPIO drive seven-segment displays, encoder knobs, relay coils, and triac interfaces. The -40C to +125C range tolerates the thermal shock of appliance door openings and motor inrush heating. The 44-PLCC package survives wave-solder and selective-solder processes common in appliance manufacturing.
Recommended
Instrumentation Front-Ends
The PIC17C42AT-33E/L is used in legacy instrumentation - bench multimeters, signal generators, and process meters - as a human-machine-interface controller. It drives LCD segments, scans keypads, and sends measured data over UART to a host PC or display. The 33 MIPS throughput handles button debouncing, menu state machines, and serial protocol parsing without timing margin concerns. The OTP memory preserves calibration constants and firmware IP for the product lifetime.
Recommended
Recommended Products Summary
Engineering reference data for PIC17C42AT-33E/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC17C42A-33E/L | PIC17C42A-33I/L | PIC17C42AT-33I/L | PIC17C42AT-25E/L |
|---|---|---|---|---|---|
| Package | 44-PLCC (J-Lead) | 44-PLCC (J-Lead) | 44-PLCC (J-Lead) | 44-PLCC (J-Lead) | 44-PLCC (J-Lead) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 33 MHz | 33 MHz | 33 MHz | 33 MHz | 25 MHz |
| Program Memory | 4 KB (2K x 16) OTP | 4 KB (2K x 16) OTP | 4 KB (2K x 16) OTP | 4 KB (2K x 16) OTP | 4 KB (2K x 16) OTP |
| RAM Size | 232 B | 232 B | 232 B | 232 B | 232 B |
| Number of I/O | 33 | 33 | 33 | 33 | 33 |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +85C | -40C to +85C | -40C to +125C |
| Shipping Format | Tape & Reel | Tube | Tube | Tape & Reel | Tape & Reel |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND |
Key Differentiators
- Highest 33 MHz speed grade in 44-PLCC PIC17C42A family (vs PIC17C42AT-25E/L)
- Extended -40C to +125C temperature range (vs PIC17C42AT-33I/L)
- Tape & Reel shipping format (vs PIC17C42A-33E/L)
Design Notes
Place a 100 nF decoupling capacitor within 5 mm of each VDD/VSS pin pair on the 44-PLCC. Add a single 10 uF bulk tantalum or ceramic capacitor at the board's PIC17C42AT-33E/L supply entry. The PIC17C42A's high-edge transient currents on I/O switching benefit from low-ESR ceramic decoupling rather than electrolytic-only designs. Estimated: typical VDD range is 4.5V to 6.0V for the PIC17C42A family - confirm exact min/max from the datasheet before power-supply design.
The 44-PLCC (J-Lead) package requires a socket or plated-through-hole land pattern with adequate annular ring for the J-leads. For surface mounting, ensure the land-pattern pad width matches the J-lead foot and that the package has at least 1.5 mm clearance to neighboring components for reliable solder joint inspection. The PIC17C42A's exposed die area means a copper pour directly under the package can serve as a ground plane thermal spreader.
Do not assume OTP parts can be re-programmed like flash - the PIC17C42AT-33E/L can only be programmed once. Validate your code on a PIC17C42A windowed CERAMIC sample or a flash-based PIC18F equivalent before committing to the OTP part. Ensure MCLR is pulled up through a proper reset circuit (typically 10 kohm + diode + capacitor) - leaving MCLR floating results in unreliable brown-out behavior and potential code execution anomalies.
Use the hardware UART/USART rather than software bit-banging when connecting to RS-232/RS-485 transceivers. At 33 MHz the PIC17C42A has limited MIPS headroom for accurate software UART at high baud rates. For long-trace oscillator routing, place the crystal within 10 mm of OSC1/OSC2 and guard the traces with a grounded copper pour. Estimated: total transient current on VDD pins can exceed 100 mA during high-speed I/O toggling - use 4-layer PCB if possible.
Compliance Information
RoHS/REACH/lead-free status [DATA_NEEDED] - PIC17C42A family predates widespread RoHS transition, likely non-RoHS but verify with Microchip material declaration. Not AEC-Q100 qualified.
