PIC17C42AT-33E/L - 33MHz 8-Bit OTP MCU, 4KB, 44-PLCC | Microchip
MPN： PIC17C42AT-33E/L ✗ 停產PIC17C42AT-33E/L 概覽
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.
直接替換替代品，適用於 PIC17C42AT-33E/L — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： PIC17C42AT-33E/L （相同外形與佔位） — 差異在於 Program Memory Type, Package, Core Architecture, Timers, Program Memory Size.
PIC17C42A-33E/L
✅ 直接替換聯絡詢價
查看資料表 →PIC17C42A-33I/L
✅ 直接替換聯絡詢價
查看資料表 →PIC17C42AT-33I/L
✅ 直接替換📋 參考替代品（不在目錄中）
PIC17C42AT-25E/L
✅ 直接替換聯絡詢價
查看資料表 →PIC17C42AT-25/PT
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →PIC17C42AT-25/PQ
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →PIC17C42AT-33E/L 最大額定值與電氣特性
| Product Family | PIC17C |
| Core | 8-bit PIC RISC |
| Series | PIC17C42A |
| 最大時脈頻率 | 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 |
| 封裝 / 外殼 | 44-PLCC (J-Lead), 16.59 x 16.59 mm |
| 安裝類型 | Surface Mount |
| 工作溫度 | -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 腳位配置
| 腳位 1 | RA0 — PORTA bit 0 (digital I/O) |
| 腳位 2 | RA1 — PORTA bit 1 (digital I/O) |
| 腳位 3 | RA2 — PORTA bit 2 (digital I/O) |
| 腳位 4 | RA3 — PORTA bit 3 (digital I/O) |
| 腳位 5 | RA4 — PORTA bit 4 (digital I/O) |
| 腳位 6 | RA5 — PORTA bit 5 (digital I/O) |
| 腳位 7 | RA6 — PORTA bit 6 (digital I/O) |
| 腳位 8 | RA7 — PORTA bit 7 (digital I/O) |
| 腳位 9 | RB0/INT — PORTB bit 0 / external interrupt |
| 腳位 10 | RB1 — PORTB bit 1 (digital I/O) |
| 腳位 11 | RB2 — PORTB bit 2 (digital I/O) |
| 腳位 12 | RB3 — PORTB bit 3 (digital I/O) |
| 腳位 13 | RB4 — PORTB bit 4 (digital I/O) |
| 腳位 14 | RB5 — PORTB bit 5 (digital I/O) |
| 腳位 15 | RB6 — PORTB bit 6 (digital I/O) |
| 腳位 16 | RB7 — PORTB bit 7 (digital I/O) |
| 腳位 17 | RC0 — PORTC bit 0 (digital I/O) |
| 腳位 18 | RC1 — PORTC bit 1 (digital I/O) |
| 腳位 19 | RC2 — PORTC bit 2 (digital I/O) |
| 腳位 20 | RC3 — PORTC bit 3 (digital I/O) |
| 腳位 21 | RC4 — PORTC bit 4 (digital I/O) |
| 腳位 22 | RC5 — PORTC bit 5 (digital I/O) |
| 腳位 23 | RC6 — PORTC bit 6 (digital I/O) |
| 腳位 24 | RC7 — PORTC bit 7 (digital I/O) |
| 腳位 25 | RD0 — PORTD bit 0 (digital I/O) |
| 腳位 26 | RD1 — PORTD bit 1 (digital I/O) |
| 腳位 27 | RD2 — PORTD bit 2 (digital I/O) |
| 腳位 28 | RD3 — PORTD bit 3 (digital I/O) |
| 腳位 29 | RD4 — PORTD bit 4 (digital I/O) |
| 腳位 30 | RD5 — PORTD bit 5 (digital I/O) |
| 腳位 31 | RD6 — PORTD bit 6 (digital I/O) |
| 腳位 32 | RD7 — PORTD bit 7 (digital I/O) |
| 腳位 33 | RE0 — PORTE bit 0 (digital I/O) |
| 腳位 34 | RE1 — PORTE bit 1 (digital I/O) |
| 腳位 35 | RE2 — PORTE bit 2 (digital I/O) |
| 腳位 36 | OSC1 — External oscillator input |
| 腳位 37 | OSC2 — External oscillator output |
| 腳位 38 | MCLR — Master clear (reset) input |
| 腳位 39 | VDD — Positive supply voltage |
| 腳位 40 | VSS — Ground reference |
| 腳位 41 | TX — UART transmit output |
| 腳位 42 | RX — UART receive input |
| 腳位 43 | VSS — Ground reference |
| 腳位 44 | VDD — Positive supply voltage |
典型應用
PIC17C42AT-33E/L 適用於 6 應用s: 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.
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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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
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推薦產品摘要
工程參考資料，適用於 PIC17C42AT-33E/L — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 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 |
主要差異化特點
- Highest 33 MHz speed grade in 44-PLCC PIC17C42A family (對比PIC17C42AT-25E/L)
- Extended -40C to +125C temperature range (對比PIC17C42AT-33I/L)
- Tape & Reel shipping format (對比PIC17C42A-33E/L)
設計說明
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.
合規資訊
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.
