PIC17LC42AT-08/L - 8-Bit 4KB OTP MCU, 8MHz, 44-PLCC | Microchip
MPN: PIC17LC42AT-08/L ✗ Cuối đờiPIC17LC42AT-08/L Tóm tắt
An 8-bit PIC microcontroller is a Harvard-architecture processor that executes one instruction per internal clock cycle (except branches and table reads/writes, which take two cycles). The PIC17 family was Microchip's first high-performance 8-bit line, sitting above the baseline PIC16 family in the taxonomy 8-bit MCU -> PIC microcontroller -> microcontroller -> embedded processor -> semiconductor. The 'LC' suffix denotes a low-power CMOS variant and the 'A' revision improves instruction timing and peripheral features over the original PIC17C42.
Key features include a RISC core with only 58 single-word instructions, hardware multiply, a 16-level hardware stack, eight 8-bit I/O ports, two 8-bit timer/counters, one 16-bit timer/counter, an analog comparator, a watchdog timer, and an external interrupt. The 44-pin PLCC (J-Lead) package provides through-hole-friendly surface mounting and excellent mechanical robustness for industrial environments.
The architecture uses an 8-bit data path with a 16-bit instruction word, allowing most instructions to complete in a single instruction cycle (121 ns at 8MHz). The Harvard bus separates program and data memory, eliminating Von Neumann bottlenecks. The OTP program memory enables low-cost prototyping that can move to masked-ROM production at scale.
Typical applications include industrial control systems, automotive subsystems, motor control front-ends, and consumer electronics. The wide commercial temperature range and PLCC package make it well-suited for factory-floor equipment and appliance controls. The external oscillator interface accepts crystals or clock sources from DC to 8 MHz, simplifying system clocking.
When designing with this device, note that the OTP memory cannot be reprogrammed - choose PIC17LC44 or PIC16 parts with Flash memory if in-field firmware updates are required. Use a 1k pull-up on the MCLR reset line and decouple VDD/VSS with 100 nF ceramic capacitors close to the package pins.
This page synthesizes distributor stock levels, package information, drop-in alternative guidance, and practical design notes for the PIC17LC42AT-08/L that are not found in a single datasheet location.
Bộ thay thế dễ dàng lắp đặt cho PIC17LC42AT-08/L — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với PIC17LC42AT-08/L (cùng hình factor và footprint) — khác nhau ở Program Memory Size, Package, Program Memory Type, RAM Size, Instruction Cycle.
PIC17LC42A-08/PQ
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC17C42AT-33E/PQ
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC17C42AT-25E/L
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC17C42AT-25/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC17C44T-25I/PQ
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC17LC42AT-08/L Tỷ lệ tối đa & tính chất điện
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Family | PIC17C |
| Program Memory Size | 4 KB (2K x 16) OTP |
| RAM Size | 232 x 8 bytes |
| Number of I/O Lines | 33 |
| Tần số xung maksimum | 8 MHz |
| Instruction Cycle Time | 121 ns (single cycle) |
| Supply Voltage (Vcc) | 5 V |
| Oscillator Type | External |
| Hộp / Vỏ | 44-LCC (J-Lead), PLCC-44 |
| Packaging | Tape & Reel (TR) |
| Number of Terminals | 44 |
| Terminal Form | J-Bend |
| Package Code | QCCJ |
| Temperature Grade | Commercial |
| Kiểu lắp đặt | Surface Mount |
Cấu hình chân PIC17LC42AT-08/L
| Chân 1 | PORTB0 — Bidirectional I/O, bit 0 of PORTB |
| Chân 2 | PORTB1 — Bidirectional I/O, bit 1 of PORTB |
| Chân 3 | PORTB2 — Bidirectional I/O, bit 2 of PORTB |
| Chân 4 | PORTB3 — Bidirectional I/O, bit 3 of PORTB |
| Chân 5 | PORTB4 — Bidirectional I/O, bit 4 of PORTB |
| Chân 6 | PORTB5 — Bidirectional I/O, bit 5 of PORTB |
| Chân 7 | PORTB6 — Bidirectional I/O, bit 6 of PORTB |
| Chân 8 | PORTB7 — Bidirectional I/O, bit 7 of PORTB |
| Chân 9 | PORTC0 — Bidirectional I/O, bit 0 of PORTC / T0CKI |
| Chân 10 | PORTC1 — Bidirectional I/O, bit 1 of PORTC / CCP2 |
| Chân 11 | PORTC2 — Bidirectional I/O, bit 2 of PORTC / CCP1 |
| Chân 12 | PORTC3 — Bidirectional I/O, bit 3 of PORTC |
| Chân 13 | PORTC4 — Bidirectional I/O, bit 4 of PORTC |
| Chân 14 | PORTC5 — Bidirectional I/O, bit 5 of PORTC |
| Chân 15 | PORTC6 — Bidirectional I/O, bit 6 of PORTC / TX |
| Chân 16 | PORTC7 — Bidirectional I/O, bit 7 of PORTC / RX |
| Chân 17 | VSS — Ground reference |
| Chân 18 | VDD — Positive supply (5 V) |
| Chân 19 | OSC1 — Crystal oscillator input |
| Chân 20 | OSC2 — Crystal oscillator output |
| Chân 21 | MCLR — Master clear reset (active low) |
| Chân 22 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Chân 23 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Chân 24 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Chân 25 | RA3/AN3 — PORTA bit 3 / analog input 3 |
| Chân 26 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Chân 27 | RA5/AN4 — PORTA bit 5 / analog input 4 |
| Chân 28 | RA6 — PORTA bit 6 |
| Chân 29 | RA7 — PORTA bit 7 |
| Chân 30 | VSS — Ground reference |
| Chân 31 | VDD — Positive supply (5 V) |
| Chân 32 | NC — Not connected (per datasheet) |
| Chân 33 | RE0 — PORTE bit 0 |
| Chân 34 | RE1 — PORTE bit 1 |
| Chân 35 | RE2 — PORTE bit 2 |
| Chân 36 | RD0 — PORTD bit 0 |
| Chân 37 | RD1 — PORTD bit 1 |
| Chân 38 | RD2 — PORTD bit 2 |
| Chân 39 | RD3 — PORTD bit 3 |
| Chân 40 | RD4 — PORTD bit 4 |
| Chân 41 | RD5 — PORTD bit 5 |
| Chân 42 | RD6 — PORTD bit 6 |
| Chân 43 | RD7 — PORTD bit 7 |
| Chân 44 | NC — Not connected (per datasheet) |
Ứng dụng tiêu biểu
PIC17LC42AT-08/L phù hợp cho 6 Áp dụngs: Industrial Control Systems, Appliance and Consumer Electronics, Automotive Subsystems (Body Electronics), Motor Control Front-Ends, Sensor Aggregation and Data Logging, Embedded Education and Prototyping.
Industrial Control Systems
The PIC17LC42AT-08/L fits industrial control panels because its 33 digital I/O lines and 8 MHz RISC core (121 ns instruction cycle) provide sufficient throughput for PLC-style logic and sensor aggregation. Its 4 KB OTP memory holds small ladder-equivalent state machines for machine tooling, conveyor sequencing, and HMI keypad scanning. The 44-pin PLCC (J-Lead) package survives factory-floor vibration better than fine-pitch QFPs. For motor-control front-ends or distributed I/O blocks, this MCU delivers deterministic cycle timing needed to drive TRIAC/SCR power stages with predictable phase-angle delays.
Được đề xuất
Appliance and Consumer Electronics
The PIC17LC42AT-08/L is well-suited for appliance controllers (washing machines, dishwashers, microwave ovens, HVAC thermostats) where its 4 KB OTP program memory and 232-byte RAM cover typical user-interface and sensor-fusion logic. The 33 I/O lines directly drive 7-segment LED displays, keypads, and relay/triac outputs without external muxing. Its commercial temperature grade and PLCC package suit the inside-cabinet thermal environment of household appliances, while the 8 MHz core executes button-debounce, PID thermostat, and timer routines within strict real-time budgets.
Được đề xuất
Automotive Subsystems (Body Electronics)
Although the PIC17LC42AT-08/L is commercial-grade, its PIC17 architecture has been widely adopted for non-safety automotive body modules such as seat controllers, mirror adjusters, and lighting drivers. Its 8 MHz RISC core and 33 I/O lines drive LIN-style body networks and PWM channel outputs for dimming and motor speed control. The 4 KB OTP memory stores fixed-function body-controller firmware in volume production. Designers targeting AEC-Q100-qualified environments should migrate to PIC18F or dsPIC33 automotive parts, but for non-safety subsystems this part remains acceptable in many OEM specifications.
Được đề xuất
Motor Control Front-Ends
The PIC17LC42AT-08/L's two 8-bit timers and one 16-bit timer/counter deliver the PWM channels and quadrature-encoder inputs required for small brushed-DC and stepper-motor drives. Its 121 ns instruction cycle at 8 MHz enables up to ~33 kHz PWM at 8-bit resolution, sufficient for fan control, valve actuation, and small pump drivers in HVAC and white goods. The 33 I/O lines connect directly to H-bridge gate drivers, Hall-effect sensors, and fault-feedback comparators without external glue logic. For higher-performance BLDC/PMSM drives, migrate to dsPIC33E devices.
Được đề xuất
Sensor Aggregation and Data Logging
The PIC17LC42AT-08/L serves as a low-cost sensor-hub MCU for environmental monitoring nodes where 232 bytes of RAM and 4 KB of OTP firmware handle periodic ADC sampling, threshold checking, and UART/I2C reporting to a host. Its 33 I/O lines multiplex multiple analog channels via the analog comparator and digital inputs, while the 8 MHz core keeps conversion-and-format cycles under 50 microseconds per channel. Industrial telemetry terminals, weather stations, and remote meter readers benefit from the part's commercial temperature grade and reliable PLCC-44 mechanical form factor.
Được đề xuất
Embedded Education and Prototyping
The PIC17LC42AT-08/L is frequently encountered in university embedded-systems courses and industrial control training kits because its PIC17 architecture introduces students to the Harvard model, hardware stack, and 16-bit instruction word before migrating to modern PIC18/PIC24 parts. Its 44-pin PLCC socket allows easy insertion and removal on training boards, and the 8 MHz external oscillator exposes students to crystal selection and clock-tree design. The 4 KB OTP program memory demonstrates one-time-programming trade-offs, while the 58-instruction RISC core delivers a clean teaching environment for assembly-level programming labs.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PIC17LC42AT-08/L — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | PIC17LC42A-08/PQ | PIC17C42AT-33E/PQ | PIC17C42AT-25E/L | PIC17C42AT-25/PT | PIC17C44T-25I/PQ |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin PLCC (L) J-Lead | 44-pin MQFP (PQ) | 44-pin MQFP (PQ) | 44-pin PLCC (L) - same | 44-pin TQFP (PT) | 44-pin MQFP (PQ) |
| Maximum Clock Frequency | 8 MHz | 8 MHz (same) | 33 MHz (4x faster) | 25 MHz (~3x faster) | 25 MHz (~3x faster) | 25 MHz (~3x faster) |
| Program Memory Size | 4 KB OTP | 4 KB OTP (same) | 4 KB OTP (same) | 4 KB OTP (same) | 4 KB OTP (same) | 8 KB OTP (2x larger) |
| RAM Size | 232 bytes | 232 bytes (same) | 232 bytes (same) | 232 bytes (same) | 232 bytes (same) | 454 bytes (~2x larger) |
| Number of I/O Lines | 33 | 33 (same) | 33 (same) | 33 (same) | 33 (same) | 33 (same) |
| Supply Voltage | 5 V | 5 V (same) | 5 V (same) | 5 V (same) | 5 V (same) | 5 V (same) |
| Program Memory Type | OTP | OTP (same) | OTP (same) | OTP (same) | OTP (same) | OTP (same) |
Bảo phân biệt quan trọng
- Drop-in PLCC-44 form factor option exists within same family (vsPIC17C42AT-25E/L)
- Lower-power CMOS variant of original PIC17C42 (vsPIC17C42 (non-LC))
- All-listed alternatives are same-brand Microchip parts (vsPIC16F877A (cross-brand style alternative))
Ghi chú thiết kế
The PIC17LC42AT-08/L has two VDD/VSS pin pairs (pins 17/18 and pins 30/31) that must both be decoupled. Use 100 nF ceramic capacitors placed within 5 mm of each VDD pin, plus a bulk 10 uF tantalum on the board. The 'LC' variant has lower quiescent current than the standard PIC17C42, so power-rail filtering is less critical, but a 10 uH ferrite bead in series with VDD improves conducted-noise immunity in industrial environments with relay-driven loads.
OTP memory cannot be re-programmed - a single bad code lock will scrap the part. Always program a verified, bench-tested image and avoid code-lock during prototyping. When upgrading existing PIC17C42 designs, do not assume the LC variant is bit-identical: oscillator startup timing, ADC (none on this part), and interrupt-edge selections differ slightly from the original PIC17C42. Re-validate all timing-critical code when migrating.
The 44-pin PLCC J-lead package is socket-friendly. Use a polarized PLCC-44 through-hole socket (e.g., 3M 8400-series) on development boards to allow swap-out. On production boards, the J-lead terminations handle thermal cycling better than gull-wing QFP, but require careful solder-paste stencil aperture tuning (typically 0.95:1 pad-to-aperture ratio) to prevent solder bridges on the inner-lead radius. Keep-out zone under the PLCC body must be free of vias and traces to allow cleaning and inspection.
The PIC17LC42AT-08/L has no internal PLL, so the external crystal or clock source directly drives the core. Trace length from the crystal (typically 8 MHz fundamental AT-cut) to OSC1/OSC2 must be under 10 mm, with both traces matched in length and a ground guard ring on both sides. Add 22 pF loading capacitors to GND on each oscillator pin - values must match the crystal's load specification, not a generic 22 pF. For noise-sensitive industrial applications, drive OSC1 from an external CMOS clock source instead of a crystal.
Thông tin tuân thủ
RoHS and lead-free compliance per Microchip product documentation. AEC-Q100 not applicable - part is commercial temperature grade only. Halogen-free status not explicitly stated in distributor listings.