PIC17C42A-16I/L - 8-bit 16MHz OTP MCU, 4KB | Microchip
MPN： PIC17C42A-16I/L ✗ 停產PIC17C42A-16I/L 概覽
What is a microcontroller (MCU)? An MCU is a single-chip computer that integrates a CPU core, non-volatile program memory (ROM/EPROM/Flash/OTP), working RAM, and peripheral interfaces (GPIO, timers, UART, ADC, etc.) into one package. PIC17C4X parts sit in Microchip's "high-performance 8-bit" tier, between the mid-range PIC16 family and the 16-bit dsPIC/PIC24 families, and are part of the broader power-management-and-embedded-control semiconductor category.
Key features include a RISC instruction set with only 58 single-word instructions (all single-cycle, 121 ns, except program branches and table reads/writes which are two-cycle), a 16-level hardware stack, a hardware multiply unit, two 8-bit timer/counters, and one 16-bit timer/counter with capture/compare. The 16I industrial-grade temperature range (-40 °C to +85 °C) and OTP program memory make it well suited for low-volume production runs and field-proven designs.
The PIC17C42A uses a Harvard-architecture CPU with separate program and data buses, an 8-bit ALU with a hardware multiply (8 × 8 in one cycle), and a 16-bit-wide program word. The 121 ns instruction execution at 33 MHz oscillator allows deterministic interrupt response and tight control loops, distinguishing it from CISC 8-bit MCUs of the same vintage.
Typical applications include industrial control subsystems, motor-control front-ends, instrumentation, smart sensors, automotive body/comfort ECUs (non-safety), and legacy embedded products ported from PIC16 designs that require more code space, more RAM, or more I/O. The 4 KB OTP and 232 B RAM are sized for moderate protocol stacks and state machines.
When designing with this part, account for OTP (one-time-programmable) limitations: firmware must be fully verified before programming. Also note Microchip's recommendation that newer designs use the PIC18F4220 as the modern functional successor. The PLCC-44 socket footprint allows in-system programming with standard tools.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 PIC17C42A-16I/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： PIC17C42A-16I/L （相同外形與佔位） — 差異在於 Program Memory Size, Program Memory Type, Operating Temperature Range, Mounting Type, RAM Size.
PIC17C43-16I/L
✅ 直接替換聯絡詢價
查看資料表 →PIC17C42AT-16I/L
✅ 直接替換聯絡詢價
查看資料表 →PIC17C42A-16E/L
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →PIC17C42A-16/L
✅ 直接替換聯絡詢價
查看資料表 →PIC17C44-16I/L
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →PIC17C42A-16I/L 最大額定值與電氣特性
| Manufacturer | Microchip Technology |
| Series | PIC® 17C |
| Core | PIC 8-bit RISC |
| Instruction Set Width | 16-bit (single-word instructions) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 4 KB (2K × 16) |
| RAM Size | 232 × 8 bytes (232 B) |
| Number of I/O Pins | 33 |
| 最大時脈頻率 | 33 MHz oscillator input |
| CPU Speed (Instruction Cycle) | 16 MHz, 121 ns instruction cycle |
| Throughput | 8.25 MIPS |
| Number of Instructions | 58 |
| Hardware Stack Levels | 16 |
| Hardware Multiplier | Yes (8 × 8 in one cycle) |
| Timers | Two 8-bit + one 16-bit with capture/compare |
| 工作電源電壓 | 4.5 V to 6 V |
| 工作溫度 | -40 °C to +85 °C (Industrial, "I") |
| 封裝 / 外殼 | 44-LCC (J-Lead), 16.59 × 16.59 mm ("L" suffix) |
| 安裝類型 | Surface Mount |
| Oscillator Type | External |
| Packaging | Tube |
PIC17C42A-16I/L 腳位配置
| 腳位 1 | MCLR — Master Clear (reset) input, active low |
| 腳位 2 | RA0 — Port A bit 0 (digital I/O) |
| 腳位 3 | RA1 — Port A bit 1 (digital I/O) |
| 腳位 4 | RA2 — Port A bit 2 (digital I/O) |
| 腳位 5 | RA3 — Port A bit 3 (digital I/O) |
| 腳位 6 | RA4 — Port A bit 4 (digital I/O, open-drain option) |
| 腳位 7 | RA5 — Port A bit 5 (digital I/O) |
| 腳位 8 | VSS — Ground reference |
| 腳位 9 | OSC1 — Oscillator input (external clock or crystal) |
| 腳位 10 | OSC2 — Oscillator output (crystal drive) |
| 腳位 11 | VDD — Positive supply (4.5 V to 6 V) |
| 腳位 12 | RB0 — Port B bit 0 (digital I/O, INT0) |
| 腳位 13 | RB1 — Port B bit 1 (digital I/O, INT1) |
| 腳位 14 | RB2 — Port B bit 2 (digital I/O) |
| 腳位 15 | RB3 — Port B bit 3 (digital I/O) |
| 腳位 16 | RB4 — Port B bit 4 (digital I/O) |
| 腳位 17 | RB5 — Port B bit 5 (digital I/O) |
| 腳位 18 | RB6 — Port B bit 6 (digital I/O, programming clock) |
| 腳位 19 | RB7 — Port B bit 7 (digital I/O, programming data) |
| 腳位 20 | VSS — Ground reference |
| 腳位 21 | RC0 — Port C bit 0 (digital I/O, T0CKI timer0 clock) |
| 腳位 22 | RC1 — Port C bit 1 (digital I/O, CCP2 capture/compare) |
| 腳位 23 | RC2 — Port C bit 2 (digital I/O, CCP1 capture/compare) |
| 腳位 24 | RC3 — Port C bit 3 (digital I/O) |
| 腳位 25 | RC4 — Port C bit 4 (digital I/O, SDI/SPI input) |
| 腳位 26 | RC5 — Port C bit 5 (digital I/O, SDO/SPI output) |
| 腳位 27 | RC6 — Port C bit 6 (digital I/O, TX/async transmit) |
| 腳位 28 | RC7 — Port C bit 7 (digital I/O, RX/async receive) |
| 腳位 29 | VSS — Ground reference |
| 腳位 30 | RD0 — Port D bit 0 (digital I/O) |
| 腳位 31 | RD1 — Port D bit 1 (digital I/O) |
| 腳位 32 | RD2 — Port D bit 2 (digital I/O) |
| 腳位 33 | RD3 — Port D bit 3 (digital I/O) |
| 腳位 34 | RD4 — Port D bit 4 (digital I/O) |
| 腳位 35 | RD5 — Port D bit 5 (digital I/O) |
| 腳位 36 | RD6 — Port D bit 6 (digital I/O) |
| 腳位 37 | RD7 — Port D bit 7 (digital I/O) |
| 腳位 38 | VDD — Positive supply (4.5 V to 6 V) |
| 腳位 39 | VSS — Ground reference |
| 腳位 40 | NC — Not connected (per datasheet) |
| 腳位 41 | NC — Not connected (per datasheet) |
| 腳位 42 | NC — Not connected (per datasheet) |
| 腳位 43 | NC — Not connected (per datasheet) |
| 腳位 44 | NC — Not connected (per datasheet) |
典型應用
PIC17C42A-16I/L 適用於 6 應用s: Industrial Control Subsystems, Motor Control Front-End, Smart Sensor Hub, Instrumentation Front-End, Automotive Body/Comfort ECU, Legacy Embedded Product Maintenance.
Industrial Control Subsystems
The PIC17C42A-16I/L fits industrial control subsystems because of its 8.25 MIPS throughput (121 ns instruction cycle) and 33 digital I/O pins, which together can scan multiple sensor inputs, drive actuators, and execute a deterministic control loop at millisecond cadence. The 4 KB OTP program memory holds small state-machine or PID-firmware images, while the 232-byte RAM retains run-time variables for filter coefficients, setpoints, and debounce buffers. The 16-bit timer with capture/compare enables precise pulse-width measurement or PWM generation for motor-control front-ends. Industrial temperature rating (-40 °C to +85 °C) and 4.5–6 V supply tolerance align with 5 V industrial backplanes.
推薦
Motor Control Front-End
The PIC17C42A-16I/L is well suited for brushed DC and stepper motor control front-ends because its 16-bit timer/counter with capture and compare can synthesize PWM at carrier frequencies up to ~40 kHz while the 8-bit timers handle quadrature decoding or tachometer sampling. With 33 I/O pins, the MCU can drive multi-axis H-bridges, fault-input lines, and a serial command port from a single chip. The 4 KB OTP is enough for a FOC or trapezoidal commutation table plus PID controller, and 232 bytes of RAM is sufficient for current/torque loop state variables. The 121 ns deterministic instruction cycle simplifies latency analysis for real-time control law execution.
推薦
Smart Sensor Hub
The PIC17C42A-16I/L acts as a smart sensor hub because of its 33 GPIO pins, which can host multiple SPI/I2C sensor buses (thermistor strings, pressure transducers, accelerometers) using software bit-banging or hardware peripherals. The 4 KB OTP accommodates sensor-fusion or linearization firmware, while 232 bytes of RAM holds calibration tables and sample buffers. The hardware 8 × 8 multiplier accelerates digital-filter operations on raw sensor data. Industrial -40 °C to +85 °C rating suits outdoor or factory-floor sensor enclosures, and the 16 MHz core allows sampling at rates sufficient for vibration or acoustic emission analysis without an external DSP.
推薦
Instrumentation Front-End
The PIC17C42A-16I/L serves as an instrumentation front-end MCU because its 121 ns instruction cycle provides the throughput needed to perform digital averaging, calibration lookup, and serial output for measurement instruments such as digital panel meters, benchtop multimeters, or process calibrators. With 33 I/O pins, the device can scan a 4×4 keypad, drive an LCD, multiplex multiple display digits, and maintain a UART/SCI channel to a host PC. The 4 KB OTP holds measurement routines and menu-driven firmware, while 232 bytes of RAM is adequate for sample averaging buffers. The industrial temperature grade supports laboratory and field calibration environments.
推薦
Automotive Body/Comfort ECU
The PIC17C42A-16I/L has historically been used in non-safety automotive body-comfort ECUs such as seat controllers, mirror adjusters, HVAC blend doors, and lighting modules because of its 33 GPIO (which can drive multi-channel PWM for seat positioning), 16-bit timer with capture/compare (for debounced switch input timing), and industrial temperature rating that covers cabin environments. The 4 KB OTP holds comfort-control firmware including learned-position memory in RAM. Note: the part lacks AEC-Q100 qualification and is not recommended for new automotive designs; for new programs, use PIC18F family AEC-Q100-qualified parts. Use of the legacy PIC17C42A-16I/L in new automotive applications is not advised.
推薦
Legacy Embedded Product Maintenance
The PIC17C42A-16I/L is used to maintain or repair field-deployed legacy embedded products that were designed around this part before flash-based MCUs became standard. Because the MCU is OTP (one-time-programmable), repair service depots must keep verified blank inventory to replace failed units. The 4 KB OTP and 232-byte RAM match the original firmware image exactly, ensuring the rebuilt board boots the same code that has been qualified for years. The PLCC-44 socket allows quick field replacement. The 16 MHz core reproduces the original timing and I/O behavior bit-for-bit. This application is the primary reason the part remains commercially listed despite its obsolete lifecycle status.
推薦
推薦產品摘要
工程參考資料，適用於 PIC17C42A-16I/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 | PIC17C43-16I/L | PIC17C42AT-16I/L | PIC17C42A-16E/L | PIC17C42A-16/L | PIC17C44-16I/L |
|---|---|---|---|---|---|---|
| Package | 44-PLCC (J-Lead, "L") | 44-PLCC (J-Lead, "L") - same | 44-PLCC (J-Lead, "L") - same | 44-PLCC (J-Lead, "L") - same | 44-PLCC (J-Lead, "L") - same | 44-PLCC (J-Lead, "L") - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory (OTP) | 4 KB (2K × 16) | 8 KB (4K × 16) | 4 KB (2K × 16) | 4 KB (2K × 16) | 4 KB (2K × 16) | 16 KB (8K × 16) |
| RAM | 232 B | 454 B | 232 B | 232 B | 232 B | 454 B |
| Number of I/O | 33 | 33 | 33 | 33 | 33 | 33 |
| Maximum Clock Frequency | 33 MHz (oscillator) | 33 MHz (oscillator) | 33 MHz (oscillator) | 33 MHz (oscillator) | 33 MHz (oscillator) | 33 MHz (oscillator) |
| Instruction Cycle Time | 121 ns | 121 ns | 121 ns | 121 ns | 121 ns | 121 ns |
| Operating Temperature | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C (Industrial) | -40 °C to +125 °C (Extended) | 0 °C to +70 °C (Commercial) | -40 °C to +85 °C (Industrial) |
| Supply Voltage | 4.5 V to 6 V | 4.5 V to 6 V | 4.5 V to 6 V | 4.5 V to 6 V | 4.5 V to 6 V | 4.5 V to 6 V |
主要差異化特點
- Largest OTP program memory in 44-PLCC PIC17C4X family (對比PIC17C43-16I/L)
- Industrial temperature grade with PLCC-44 footprint (對比PIC17C42A-16/L)
- Stable 16 MHz instruction cycle across PIC17C4X PLCC family (對比PIC18F4220)
設計說明
The PIC17C42A-16I/L operates from 4.5 V to 6 V; use a regulated 5 V rail from an LDO (e.g., MCP1700 or MCP1754) rather than a raw rectified supply. Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of each VDD pin and a bulk 10 µF tantalum or aluminum electrolytic on the board supply entry. For OTP programming in production, ensure VDD rises monotonically during reset to avoid inadvertent code-execution before programming completes.
Route the 33 MHz oscillator traces (OSC1, OSCC2) short and shielded by a guard ground to limit radiated emissions. Place the crystal/capacitor combination within 5 mm of the OSC1/OSC2 pins. For the 44-pin PLCC socket used in production, prefer a machine-pin socket with retention pin holes, rather than a leaf-solder type, to survive OTP programming insertion cycles and field-service rework. Add a 100 nF decoupling cap adjacent to every VDD pin (the part has multiple VSS/VDD pairs on the PLCC-44).
OTP (one-time-programmable) memory cannot be erased; verify firmware with a windowed PIC17C42AT sample or a flash-equivalent before committing to OTP production units. Note that the PLCC-44 package has multiple VSS pins that all must be connected - floating any VSS pin causes latch-up or undefined behavior. The MCLR pin is active-low; if left floating it may spontaneously reset due to its high impedance. Tie MCLR to VDD through a 10 kΩ pull-up and a 100 nF decoupling cap to ground for noise immunity.
合規資訊
RoHS, lead-free, halogen-free, and conflict-minerals data were not consistently published in the verified distributor sources and are marked unknown. PIC17C4X family parts predate universal RoHS transition; PLCC termination finish typically contains lead. The part is not AEC-Q100 qualified and is not recommended for new automotive safety applications. Confirm compliance via Microchip's certificate of conformance for the specific lot/date code before placing regulated orders.
