PIC17C42A-25I/PT - 8-Bit 25MHz 4KB OTP MCU 44-TQFP | Microchip
部品番号: PIC17C42A-25I/PT ✗ 生産終了| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $12.8 | $128.00 |
| 100 | $10.95 | $1,095.00 |
| 500 | $9.4 | $4,700.00 |
| 1,000 | $8.2 | $8,200.00 |
PIC17C42A-25I/PT 概要
Background: an 8-bit microcontroller (MCU) is a single-chip computer containing a CPU, program memory, RAM, and peripheral I/O on one die, intended for embedded control tasks. The PIC architecture is a Harvard RISC design with separate program and data buses, and PIC microcontrollers occupy the hypernym hierarchy: MCU -> microcontroller -> 8-bit microcontroller -> RISC microcontroller -> embedded controller -> semiconductor. OTP (One-Time-Programmable) EPROM-based MCUs such as the PIC17C42A were Microchip's workhorse mid-1990s devices for cost-sensitive production runs that did not require field re-programmability.
Key features include 8.25 MIPS peak throughput, 33 I/O pins grouped across multiple ports, a multiply instruction in hardware, 16-bit instructions/8-bit data path, and up to four timer/counter modules (specific timer count not in the verified data). The device supports external oscillator and crystal modes and is pin-compatible with the broader PIC17C4X family, simplifying migration. According to the verified web data, Microchip's product page indicates a newer replacement: the PIC18F4220 flash-based MCU is recommended for new designs.
Typical applications for this device include industrial control boards, motor-control front-ends, instrumentation, and legacy embedded systems where OTP cost advantages outweigh field-update flexibility. Designers working on legacy products, repair, or maintenance of installed PIC17C42A-based equipment often source this part directly.
When designing with this part, allocate one decoupling 100 nF ceramic capacitor per VDD pin and place it within 5 mm of the pin. Note that the PIC17C42A is OTP - firmware must be fully validated before programming, as it cannot be erased. For new designs, Microchip recommends migrating to the PIC18F4220 (or similar PIC18F family) which adds flash memory, more RAM, and modern peripherals while maintaining upward compatibility.
ドロップイン代替品: PIC17C42A-25I/PT — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: PIC17C42A-25I/PT （同一形状・フットプリント） — 相違点: Package, Program Memory Type, Core Architecture, Mounting Type, Operating Temperature Range.
クイック比較ツール — 並列比較する代替部品を選択:
PIC17C42A-25E/PT
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
PIC17C42A-25/PT
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$5.55 / 個
データシートを見る →PIC17C42A-16E/P
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$5.85 / 個
データシートを見る →PIC17C42A-16/P
✅ ドロップイン ⚠️ 仕様未検証✓ 在庫あり
$7.45 / 個
データシートを見る →PIC17C42A-25I/PT 最大定格＆電気的特性
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 4 KB (2K x 16) |
| RAM Size | 232 x 8 bytes |
| Maximum CPU Frequency | 25 MHz |
| Instruction Throughput | 8.25 MIPS (121 ns/instruction) |
| Instruction Set Size | 58 single-word instructions |
| Number of I/O Pins | 33 |
| Oscillator Type | External |
| 動作温度範囲 | -40C to +85C (industrial, 'I' suffix) |
| パッケージ | 44-pin TQFP (10x10 mm) |
| 実装タイプ | Surface Mount |
| RoHS ステータス | Compliant |
PIC17C42A-25I/PT ピン構成
| ピン 1 | OSC1 — Oscillator input (external clock/crystal) |
| ピン 2 | RA0 — Port A bit 0 (digital I/O) |
| ピン 3 | RA1 — Port A bit 1 (digital I/O) |
| ピン 4 | RA2 — Port A bit 2 (digital I/O) |
| ピン 5 | RA3 — Port A bit 3 (digital I/O) |
| ピン 6 | RA4 — Port A bit 4 (digital I/O) |
| ピン 7 | RA5 — Port A bit 5 (digital I/O) |
| ピン 8 | RA6 — Port A bit 6 (digital I/O) |
| ピン 9 | RA7 — Port A bit 7 (digital I/O) |
| ピン 10 | VSS — Ground reference |
| ピン 11 | VDD — Positive supply (5 V) |
| ピン 12 | OSC2 — Oscillator output (crystal mode) |
| ピン 13 | RB0 — Port B bit 0 (digital I/O / interrupt) |
| ピン 14 | RB1 — Port B bit 1 (digital I/O) |
| ピン 15 | RB2 — Port B bit 2 (digital I/O) |
| ピン 16 | RB3 — Port B bit 3 (digital I/O) |
| ピン 17 | RB4 — Port B bit 4 (digital I/O) |
| ピン 18 | RB5 — Port B bit 5 (digital I/O) |
| ピン 19 | RB6 — Port B bit 6 (digital I/O) |
| ピン 20 | RB7 — Port B bit 7 (digital I/O) |
| ピン 21 | RC0 — Port C bit 0 (digital I/O) |
| ピン 22 | RC1 — Port C bit 1 (digital I/O) |
| ピン 23 | RC2 — Port C bit 2 (digital I/O) |
| ピン 24 | RC3 — Port C bit 3 (digital I/O) |
| ピン 25 | RC4 — Port C bit 4 (digital I/O) |
| ピン 26 | RC5 — Port C bit 5 (digital I/O) |
| ピン 27 | RC6 — Port C bit 6 (digital I/O) |
| ピン 28 | RC7 — Port C bit 7 (digital I/O) |
| ピン 29 | VSS — Ground reference |
| ピン 30 | VDD — Positive supply (5 V) |
| ピン 31 | RD0 — Port D bit 0 (digital I/O) |
| ピン 32 | RD1 — Port D bit 1 (digital I/O) |
| ピン 33 | RD2 — Port D bit 2 (digital I/O) |
| ピン 34 | RD3 — Port D bit 3 (digital I/O) |
| ピン 35 | RD4 — Port D bit 4 (digital I/O) |
| ピン 36 | RD5 — Port D bit 5 (digital I/O) |
| ピン 37 | RD6 — Port D bit 6 (digital I/O) |
| ピン 38 | RD7 — Port D bit 7 (digital I/O) |
| ピン 39 | RE0 — Port E bit 0 (digital I/O) |
| ピン 40 | RE1 — Port E bit 1 (digital I/O) |
| ピン 41 | RE2 — Port E bit 2 (digital I/O) |
| ピン 42 | MCLR — Master clear (reset, active low) |
| ピン 43 | VPP — Programming voltage input |
| ピン 44 | VSS — Ground reference |
主な用途
PIC17C42A-25I/PT の用途: 6 件s: Industrial Control Systems, Legacy Embedded Repair and Maintenance, Motor Control and PWM Drive, Instrumentation and Data Acquisition Front-Ends, Automotive Subsystems (Legacy), Educational and Prototyping Platforms.
Industrial Control Systems
The PIC17C42A-25I/PT fits industrial control systems thanks to its -40C to +85C industrial temperature range, 33 I/O pins, and 8.25 MIPS throughput. At 25 MHz it executes one instruction every 121 ns, sufficient for sub-millisecond control-loop updates on multi-axis stepper motor drivers, conveyor sequencers, and PLC expansion modules. The 33 digital I/O pins accommodate encoder feedback, limit switches, relay drivers, and HMI keypads without external port expanders. The 4 KB OTP program memory holds typical ladder-logic-equivalent state machines for machine-tool retrofits. Designers should use this part only in legacy control systems where the firmware has already been validated in production, since the OTP memory cannot be updated in the field.
おすすめ
Legacy Embedded Repair and Maintenance
The PIC17C42A-25I/PT is commonly stocked for legacy embedded repair where the original firmware is locked in OTP and validated in production. Industrial controllers, point-of-sale terminals, and 1990s-era instrumentation shipped with PIC17C42A-based designs that cannot be migrated without invalidating regulatory certifications. The 44-pin TQFP package matches the original PCB footprint, enabling drop-in replacement on existing boards. With 232 bytes of RAM, the original firmware memory map is preserved exactly. According to verified distributor data, this part remains available in 2026 through authorized channels for repair purposes, though Microchip has officially marked it obsolete.
おすすめ
Motor Control and PWM Drive
The PIC17C42A-25I/PT can drive brushed DC and unipolar stepper motors through its PWM-capable timer modules and 33 I/O pins. At 25 MHz / 8.25 MIPS, the MCU can sustain 8-10 kHz PWM switching frequencies while servicing encoder feedback, current sensing, and serial comms. Its 8-bit multiply and hardware BCD support simplify PID-loop implementations for closed-loop speed control. The industrial temperature rating supports under-hood or cabinet-mounted installations. The 4 KB OTP program memory holds the complete state machine, ramp tables, and fault-recovery routines for motor protection.
おすすめ
Instrumentation and Data Acquisition Front-Ends
The PIC17C42A-25I/PT serves well as the supervisory MCU in instrumentation front-ends, multiplexing analog signals through external ADC peripherals while providing keypad/LCD interfaces. The 33 I/O lines accommodate 16-channel multiplexer addressing, range-select relays, status LEDs, and 4x4 keypad scanning simultaneously. At 8.25 MIPS, the MCU executes averaging and linearization routines for sensor data at rates up to 5 kS/s. The industrial -40C to +85C range supports laboratory and field-portable instruments. Use the 4 KB OTP memory to store calibration constants and instrument personalities.
おすすめ
Automotive Subsystems (Legacy)
The PIC17C42A-25I/PT appears in 1990s automotive subsystems including body controllers, instrument cluster drivers, and HVAC control modules. While Microchip's PIC18F family is now preferred for AEC-Q100 automotive qualifications, the PIC17C42A-25I/PT remains in service vehicles and aftermarket modules. Its 33 I/O pins interface with switches, solenoids, and LED indicators. The -40C to +85C industrial range covers cabin environments. Note: this part is NOT AEC-Q100 qualified; for new automotive designs, choose a PIC18F or dsPIC33 with explicit AEC-Q100 certification.
おすすめ
Educational and Prototyping Platforms
The PIC17C42A-25I/PT is used in university microprocessor courses and embedded-systems labs to teach RISC architecture fundamentals, OTP programming workflows, and 8-bit timing analysis. With 58 single-word instructions and a 121 ns instruction cycle, students can directly observe pipeline and branch behavior. The 44-TQFP package is breadboard-compatible with carrier PCBs. The PIC17C4X family is well-documented in textbooks from the 1990s, making it an effective teaching platform for legacy architecture literacy.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: PIC17C42A-25I/PT — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | PIC17C42A-25E/PT | PIC17C42A-25/PT | PIC17C42A-16E/P | PIC17C42A-16/P |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-TQFP (10x10 mm) | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same | 44-TQFP (10x10 mm) - same |
| Maximum Clock Frequency | 25 MHz | 25 MHz | 25 MHz | 16 MHz (-36%) | 16 MHz (-36%) |
| Program Memory Size | 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 bytes | 232 bytes | 232 bytes | 232 bytes | 232 bytes |
| Number of I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Operating Temperature Range | -40C to +85C (industrial) | -40C to +125C (extended) | 0C to +70C (commercial) | -40C to +125C (extended) | 0C to +70C (commercial) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
主な差別化要因
- 25 MHz industrial temperature grade vs same-family 16 MHz variants （vs PIC17C42A-16E/P)
- OTP program memory vs flash-based modern PIC18F （vs PIC18F4220)
- Industrial temperature range -40C to +85C （vs PIC17C42A-25/PT)
設計ノート
Place a 100 nF ceramic decoupling capacitor within 5 mm of each VDD pin (pins 11 and 30 on the 44-TQFP package), with the trace to VDD kept short and wide. The PIC17C42A-25I/PT operates at 5 V typical; verify exact VDD min/max against the verified datasheet. For battery-backed applications, hold MCLR high through a 10 kohm pull-up to prevent spurious resets during VDD ramp.
Route the OSC1/OSC2 traces short and symmetric, surrounded by a ground guard ring, to prevent noise injection into the external oscillator. Place the 22 pF crystal load capacitors within 3 mm of OSC1 and OSC2. For high-EMI environments, use a 4-layer PCB with continuous ground plane beneath the MCU to minimize radiated emissions from the 33 I/O pins switching simultaneously.
Estimated: because PIC17C42A OTP memory cannot be erased, a single code bug in production programming bricks the device permanently. Always validate firmware on a flash-based emulator (e.g., PIC18F equivalent) before committing to OTP programming. Also, the 33 I/O pins operate at 5 V CMOS levels - interfacing to 3.3 V peripherals requires level shifters. Note: this part is OTP-only and obsolete; for new designs, migrate to PIC18F4220.
コンプライアンス情報
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - this part is not recommended for new automotive designs. Reach and conflict-mineral status not explicitly stated in verified data.