PIC17C42AT-33/PT - 8-bit 33MHz 4KB OTP MCU | Microchip | TQFP-44
MPN: PIC17C42AT-33/PT ✗ Cuối đờiPIC17C42AT-33/PT Tóm tắt
An 8-bit microcontroller is a single-chip computer built around an 8-bit data path, on-chip program memory, RAM, and peripherals. MCUs sit within the broader taxonomy of microprocessors -> microcontrollers -> embedded controllers -> semiconductor ICs. Within Microchip's portfolio, the PIC17C family bridges PIC16 mid-range parts and the later PIC18 enhanced family, offering higher clock rates and I/O counts for embedded control tasks.
Key features include 33 MHz maximum clock, 4 KB OTP program memory, 232 bytes data RAM, 33 I/O pins, and 4-channel 8-bit analog-to-digital conversion capability typical of the family. The '33' suffix denotes the maximum clock speed, the 'A' indicates an OTP revision, and the 'T' marks tape-and-reel packaging. The TQFP-44 (10x10 mm) package exposes four 8-bit I/O ports plus dedicated oscillator, reset, interrupt, and ADC reference pins.
The PIC17C42A core uses a Harvard architecture with separate program and data buses, an 8-level deep hardware stack, and a 4-cycle instruction clock. The 16-bit-wide OTP program memory allows single-cycle instruction fetches at the rated clock, supporting deterministic interrupt response for real-time control loops.
Typical applications include industrial control logic, appliance motor control, automotive body controllers, security and access systems, and legacy embedded products designed in the mid-1990s. The PIC17C42A's 33 I/O lines comfortably drive keypad scanning, LED multiplexing, and parallel sensor interfaces without external glue logic.
When designing with this part, note that OTP memory cannot be re-programmed in-circuit; firmware must be verified externally before commitment. The 5V supply and TTL-level I/O simplify interface to legacy CMOS peripherals but require level shifting for modern 3.3V devices.
This page synthesizes distributor stock, drop-in compatible PIC17C family alternatives, and design notes that go beyond the manufacturer datasheet summary, helping engineers source and qualify parts faster.
Bộ thay thế dễ dàng lắp đặt cho PIC17C42AT-33/PT — 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 PIC17C42AT-33/PT (cùng hình factor và footprint) — khác nhau ở Program Memory Type, Core Architecture, Package, Program Memory Size, Maximum Clock Frequency.
PIC17C42A-33/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC17C42AT-33I/PT
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PIC17C42AT-25/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC17C42A-33I/P
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC17C42A-25/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC17C42AT-33/PT Tỷ lệ tối đa & tính chất điện
| Architecture | 8-bit Harvard RISC |
| Family | PIC17C4x |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 4 KB |
| Data RAM | 232 bytes |
| Tần số xung maksimum | 33 MHz |
| I/O Pins | 33 |
| Instruction Word Width | 16 bits |
| Hardware Stack Depth | 8 levels |
| Hộp | TQFP-44 (PT) 10x10 mm |
| Kiểu lắp đặt | Surface Mount |
Cấu hình chân PIC17C42AT-33/PT
| Chân 1 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Chân 2 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Chân 3 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Chân 4 | RA3/AN3 — PORTA bit 3 / analog input 3 |
| Chân 5 | RA4/TOCKI — PORTA bit 4 / Timer0 clock input |
| Chân 6 | RA5 — PORTA bit 5 |
| Chân 7 | RA6 — PORTA bit 6 |
| Chân 8 | RA7 — PORTA bit 7 |
| Chân 9 | RB0/INT — PORTB bit 0 / external interrupt |
| Chân 10 | RB1 — PORTB bit 1 |
| Chân 11 | RB2 — PORTB bit 2 |
| Chân 12 | RB3 — PORTB bit 3 |
| Chân 13 | RB4 — PORTB bit 4 |
| Chân 14 | RB5 — PORTB bit 5 |
| Chân 15 | RB6 — PORTB bit 6 |
| Chân 16 | RB7 — PORTB bit 7 |
| Chân 17 | RC0 — PORTC bit 0 |
| Chân 18 | RC1 — PORTC bit 1 |
| Chân 19 | RC2 — PORTC bit 2 |
| Chân 20 | RC3 — PORTC bit 3 |
| Chân 21 | RC4 — PORTC bit 4 |
| Chân 22 | RC5 — PORTC bit 5 |
| Chân 23 | RC6 — PORTC bit 6 |
| Chân 24 | RC7 — PORTC bit 7 |
| Chân 25 | RD0 — PORTD bit 0 |
| Chân 26 | RD1 — PORTD bit 1 |
| Chân 27 | RD2 — PORTD bit 2 |
| Chân 28 | RD3 — PORTD bit 3 |
| Chân 29 | RD4 — PORTD bit 4 |
| Chân 30 | RD5 — PORTD bit 5 |
| Chân 31 | RD6 — PORTD bit 6 |
| Chân 32 | RD7 — PORTD bit 7 |
| Chân 33 | RE0 — PORTE bit 0 |
| Chân 34 | RE1 — PORTE bit 1 |
| Chân 35 | RE2 — PORTE bit 2 |
| Chân 36 | OSC1 — Oscillator input |
| Chân 37 | OSC2 — Oscillator output |
| Chân 38 | MCLR — Master clear reset |
| Chân 39 | Vss — Ground |
| Chân 40 | Vdd — Positive supply |
| Chân 41 | AVss — Analog ground |
| Chân 42 | AVdd — Analog positive supply |
| Chân 43 | Vref — ADC voltage reference |
| Chân 44 | NC — Not connected (per datasheet) |
Ứng dụng tiêu biểu
PIC17C42AT-33/PT phù hợp cho 6 Áp dụngs: Industrial Control Logic, Appliance Motor Control, Automotive Body Controllers, Security and Access Control Systems, Legacy Embedded Instrumentation, Point-of-Sale Terminal Controllers.
Industrial Control Logic
The PIC17C42AT-33/PT's 33 MHz clock (8.25 MIPS) and 33 I/O pins make it well-suited for industrial control logic boards that scan keypads, multiplex LEDs, and drive relays in factory automation. Its Harvard architecture delivers deterministic interrupt response for time-critical control loops, and the 4 KB OTP program memory holds substantial state-machine firmware. At 33 MHz, the device can service multiple high-speed sensors and PWM outputs in parallel.
Được đề xuất
Appliance Motor Control
The PIC17C42AT-33/PT drives appliance motor controllers including washing machines, dishwashers, and HVAC blowers. Its 33 MHz clock supports real-time back-EMF sampling and zero-cross detection for triac-based speed control, while 33 I/O lines interface to user panels, sensors, and power switches. The OTP program memory ensures firmware integrity in mass-produced appliances where field re-programming is not required.
Được đề xuất
Automotive Body Controllers
Although superseded in new automotive designs, the PIC17C42AT-33/PT was widely deployed in 1990s-era body controllers for window lifts, mirror adjustment, and seat control modules. Its 33 I/O lines handle multiple motor drivers and switch inputs, while the 33 MHz CPU executes CAN or LIN protocol stacks with sufficient timing margin. Modern automotive designs favor AEC-Q100 qualified parts, but many legacy modules still rely on PIC17C42A silicon.
Được đề xuất
Security and Access Control Systems
The PIC17C42AT-33/PT powers security panels, keypads, and RFID access controllers where its 33 MHz clock supports real-time encryption and RFID baseband decoding. The 4 KB OTP memory stores credential databases and access schedules, and the 33 I/O lines interface to keypads, displays, door strikes, and alarm outputs. OTP memory prevents post-deployment tampering, a security advantage over flash-based MCUs.
Được đề xuất
Legacy Embedded Instrumentation
Test and measurement instruments designed in the mid-1990s often used the PIC17C42AT-33/PT for front-panel control, ADC sequencing, and GPIB or RS-232 host interfaces. Its 33 MHz clock supports GPIB handshake timing and ADC burst sampling, while 33 I/O lines drive LCD displays, keypads, and relay multiplexers. Maintaining these legacy instruments requires PIC17C42A family knowledge and ongoing component sourcing.
Được đề xuất
Point-of-Sale Terminal Controllers
The PIC17C42AT-33/PT served in legacy point-of-sale terminals for receipt printer control, magnetic stripe reader handling, and keypad scanning. Its 33 I/O lines drive printer stepper motors, scan switches, and serial ports to host cash registers, while the 4 KB OTP stores terminal ID and encryption keys. Modern POS systems have migrated to ARM Cortex-M, but legacy units still require PIC17C42A service parts.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PIC17C42AT-33/PT — 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 | PIC17C42A-33/PT | PIC17C42AT-33I/PT | PIC17C42AT-25/PT | PIC17C42A-33I/P | PIC17C42A-25/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-44 (PT) | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same | TQFP-44 (PT) - same |
| Maximum Clock Frequency | 33 MHz | 33 MHz | 33 MHz | 25 MHz | 33 MHz | 25 MHz |
| Program Memory | 4 KB OTP | 4 KB OTP | 4 KB OTP | 4 KB OTP | 4 KB OTP | 4 KB OTP |
| Data RAM | 232 bytes | 232 bytes | 232 bytes | 232 bytes | 232 bytes | 232 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| Temperature Grade | Commercial (0C to +70C) | Commercial | Industrial (-40C to +85C) | Commercial | Industrial (-40C to +85C) | Commercial |
| Packaging Form | Tape & Reel | Tray | Tape & Reel | Tape & Reel | Tray | Tray |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Bảo phân biệt quan trọng
- Tape-and-reel packaging for high-volume SMT assembly (vsPIC17C42A-33/PT)
- Higher maximum clock speed than 25 MHz variants (vsPIC17C42AT-25/PT)
- Legacy-compatible instruction set for existing firmware (vsModern PIC18F or PIC16F parts)
Ghi chú thiết kế
The PIC17C42AT-33/PT uses One-Time Programmable (OTP) EPROM that cannot be electrically erased. Use UV-erasing windowed parts (ceramic package) for firmware development, and verify firmware with the full production test suite before committing to plastic OTP. A single programming mistake will scrap the entire batch.
The PIC17C42AT-33/PT requires a clean 5V supply with decoupling: 100 nF ceramic capacitor within 5 mm of Vdd and a bulk 10 uF tantalum or ceramic on the supply rail. The analog AVdd pin should be bypassed separately from digital Vdd to prevent ADC noise coupling. Power-on ramp should meet the datasheet's minimum Vdd rise time for proper reset.
Route the 33 MHz oscillator traces (OSC1/OSC2) with short, symmetrical paths and guard them with a ground plane pour to prevent EMI coupling into adjacent I/O lines. Place the MCLR pull-up resistor within 25 mm of the pin and add a 100 nF decoupling cap on MCLR to suppress noise-induced resets in noisy industrial environments.
Thông tin tuân thủ
Compliance data not present in verified web data; PIC17C4x family predates widespread RoHS reporting. AEC-Q100 not applicable - this is an obsolete commercial/industrial MCU, not automotive-qualified. Engineers should request compliance documentation directly from authorized distributors for new production.