PIC12F635-I/MF - 8-Bit MCU, 20MHz, 1.75KB Flash, 8-DFN | Microchip
MPN： PIC12F635-I/MF ✓ 啟用中PIC12F635-I/MF 概覽
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, RAM, and peripherals on a single die. The PIC10/12 family of mid-range core MCUs is widely used as cost-optimized glue logic and sensor interface controllers in space-constrained designs. Within the broader taxonomy, PIC12F635 belongs to the enhanced mid-range 8-bit MCU category, with its RISC single-cycle instruction set delivering deterministic interrupt latency and ~5 MIPS peak throughput at 20 MHz, suitable for deterministic control loops where a 32-bit MCU would be over-spec.
Key features include nanoWatt power management with multiple sleep modes (typically sub-1 uA standby), a hardware USART/SPI/I2C-capable EUSART block on selected variants, internal 4 MHz and 31 kHz oscillators reducing external component count, and Microchip's In-Circuit Serial Programming (ICSP) interface for field upgrades. The on-chip enhanced comparator supports analog signal conditioning without an external op-amp, while two timer/counters and a watchdog timer enable closed-loop control and fail-safe operation. Programming is supported by the free MPLAB X IDE and XC8 compiler toolchain.
The device targets cost-sensitive 8-bit applications including PIR motion sensor signal chains, battery-powered remote controls, LED driver controllers, fan/relay control, security PIR front-ends, simple sensor nodes, and consumer appliance user-interface sub-MCUs. Its 8-pin DFN package keeps the board footprint to roughly 6x5 mm while exposing six I/O pins through multiplexed peripheral functions. Typical designs pair the PIC12F635-I/MF with a 3V coin cell or USB-powered linear regulator, a small EEPROM or sensor on the I2C bus, and a low-side MOSFET or opto-triac load driver.
When designing with the PIC12F635-I/MF, ensure decoupling is placed within 3 mm of VDD with at least a 100 nF X7R ceramic plus a bulk tantalum. Reserve GP3/MCLR for the ICSP programming header unless the internal MCLR disable is configured, and respect the 20 MHz maximum Fosc when VDD drops below 4.5V (4.5V-5.5V required for full-speed operation). This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet.
直接替換替代品，適用於 PIC12F635-I/MF — 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： PIC12F635-I/MF （相同外形與佔位） — 差異在於 Package, ADC, Operating Temperature, MSL Level, Core Architecture.
PIC12F635-E/MF
✅ 直接替換聯絡詢價
查看資料表 →PIC12F635T-I/MF
✅ 直接替換📋 參考替代品（不在目錄中）
PIC12F1840-E/MF
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →PIC12F1571-E/MF
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →PIC12F1501T-I/MU
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →PIC12F1572-I/MS
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →PIC12F635-I/MF 最大額定值與電氣特性
| Core Architecture | PIC12 enhanced mid-range 8-bit RISC |
| Program Memory (Flash) | 1.75 KB (1K x 14 words) |
| Data SRAM | 64 bytes |
| Data EEPROM | 128 bytes |
| Maximum Clock Speed | 20 MHz |
| Operating Voltage Range | 2.0 V to 5.5 V (4.5 V-5.5 V for full 20 MHz) |
| I/O Pins | 6 |
| 封裝 | 8-pin DFN-S (6x5 mm) |
| 工作溫度範圍 | -40 C to +85 C (industrial) |
| Peripherals | Enhanced Comparator, 2 Timers, WDT, BOD, POR, EUSART |
| ADC | None (analog via comparator only) |
| Internal Oscillator | 4 MHz and 31 kHz selectable |
| Programming Interface | ICSP (In-Circuit Serial Programming) |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant |
| MSL 等級 | 1 |
| Peak Throughput | 5 MIPS at 20 MHz |
PIC12F635-I/MF 腳位配置
| 腳位 1 | VDD — Positive supply voltage (2.0V to 5.5V) |
| 腳位 2 | GP5/T1CKI/OSC1/CLKIN — General-purpose I/O / Timer1 clock input / external oscillator input |
| 腳位 3 | GP4/AN3/T1G/OSC2/CLKOUT — General-purpose I/O / Timer1 gate / oscillator output / clockout |
| 腳位 4 | GP3/MCLR/VPP — General-purpose I/O / Master Clear (reset, active low) / ICSP programming voltage |
| 腳位 5 | GP2/COUT/T0CKI/INT — General-purpose I/O / Comparator output / Timer0 clock / external interrupt |
| 腳位 6 | GP1/CIN-/ICSPCLK — General-purpose I/O / Comparator inverting input / ICSP clock |
| 腳位 7 | GP0/CIN+/ICSPDAT — General-purpose I/O / Comparator non-inverting input / ICSP data |
| 腳位 8 | VSS — Ground reference |
典型應用
PIC12F635-I/MF 適用於 6 應用s: PIR Motion Sensor Front-End, Battery-Powered Remote Control, LED Lighting Controller, Small Fan or Relay Controller, Security PIR Sensor Hub, Consumer Appliance User Interface.
PIR Motion Sensor Front-End
The PIC12F635-I/MF fits PIR motion sensor signal chains because it integrates a low-power enhanced comparator to directly condition the PIR op-amp output and a 20 MHz mid-range core for envelope detection. With nanoWatt sleep currents typically sub-1 uA and a 2.0V-5.5V supply range, it can run on two AA cells for multi-year battery life. The six I/O pins drive the alarm LED, relay or opto-triac load, and PIR analog front-end without an external ADC. The 8-pin DFN package fits behind the Fresnel lens housing. Practical designs pair it with a Microchip MCP73831 Li-ion charger or a 3V linear regulator and use the internal comparator to set the detection threshold without external op-amps.
推薦
Battery-Powered Remote Control
The PIC12F635-I/MF's 2.0V-5.5V supply, 1.75 KB Flash, and nanoWatt sleep modes make it a natural choice for coin-cell or 2xAAA remote controls. The internal 31 kHz oscillator drives a low-duty-cycle keypad scan loop with sub-uA quiescent current, and the 20 MHz fast clock wakes on interrupt to handle IR or RF transmission bursts. The 8-pin DFN package fits inside a slim remote housing, leaving room for a coin cell and a PCB antenna for sub-GHz transmit. Real-world designs use PICkit-programmed custom IR protocols and rely on the brown-out detect (BOD) to prevent brown-out-induced lockups during battery end-of-life.
推薦
LED Lighting Controller
The PIC12F635-I/MF drives low-end LED lighting controllers by using the enhanced comparator to sense a potentiometer or photodiode for brightness control and one of its timers to generate PWM for LED dimming. With 20 MHz throughput, it can implement soft-fade transitions and color-mixing state machines in firmware while still leaving 70-80% of the 1.75 KB Flash for application code. The 8-pin DFN package drops into a recessed LED driver PCB, and the -40C to +85C range covers indoor fixtures and outdoor enclosures. Designers typically pair it with a low-side N-channel MOSFET like the DMG3415U for PWM dimming.
推薦
Small Fan or Relay Controller
The PIC12F635-I/MF handles small fan speed controllers or relay switching where deterministic on/off control plus RPM feedback matters more than computing horsepower. The enhanced comparator reads back-EMF or tachometer pulses from a 2-wire fan, while one timer generates the PWM drive and another handles the watchdog. Operating from 2.0V to 5.5V supports 3.3V and 5V rails, and the industrial temperature range tolerates under-hood or appliance interior environments. The 6 I/O pins map cleanly to fan-tach input, PWM output, fault LED, and a serial debug port.
推薦
Security PIR Sensor Hub
The PIC12F635-I/MF acts as a low-cost sensor hub in distributed security systems by aggregating one PIR or reed-switch input via the comparator and forwarding state over a single-wire UART link to a master controller. Its 128-byte EEPROM stores calibration and tamper-detection parameters, while the 1.75 KB Flash holds the simple state-machine firmware. The 8-pin DFN package mounts on a tiny sensor carrier PCB that fits inside a door-frame junction box, and the -I industrial temperature grade covers outdoor and unheated garage installations.
推薦
Consumer Appliance User Interface
The PIC12F635-I/MF serves as a sub-MCU in appliance user-interface boards, scanning 2-3 mechanical buttons and driving 2-3 indicator LEDs. The enhanced comparator wakes the device from sleep on button press via a resistor-divider network, allowing the rest of the system to stay in deep sleep until user interaction. The internal 4 MHz oscillator provides accurate timing for debounce and LED blink patterns without external crystals. The DFN-8 package measures only 6x5 mm, fitting comfortably behind a small appliance front-panel PCB alongside a 7-segment display driver.
推薦
推薦產品摘要
工程參考資料，適用於 PIC12F635-I/MF — 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 | PIC12F635-E/MF | PIC12F635T-I/MF | PIC12F1840-E/MF | PIC12F1571-E/MF | PIC12F1501T-I/MU | PIC12F1572-I/MS |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 8-pin DFN-S (6x5 mm) | 8-pin DFN-S (6x5 mm) - same | 8-pin DFN-S (6x5 mm) - same | 8-pin DFN-S (6x5 mm) - same | 8-pin DFN-S (6x5 mm) - same | 8-pin DFN-S - same family | 8-pin DFN-S - same family |
| Flash Memory | 1.75 KB | 1.75 KB | 1.75 KB | 7 KB | 1.75 KB | 1.75 KB | 3.5 KB |
| SRAM | 64 bytes | 64 bytes | 64 bytes | 256 bytes | 128 bytes | 64 bytes | 128 bytes |
| EEPROM | 128 bytes | 128 bytes | 128 bytes | 256 bytes | unlisted | unlisted | unlisted |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 32 MHz | 20 MHz | 20 MHz | 20 MHz |
| ADC | None (comparator only) | None | None | 10-bit | 10-bit | 10-bit | 10-bit |
| Operating Temperature | -40 C to +85 C | -40 C to +125 C | -40 C to +85 C | -40 C to +125 C | -40 C to +125 C | -40 C to +85 C | -40 C to +85 C |
主要差異化特點
- Lowest-cost 8-bit MCU with hardware comparator in 8-pin DFN (對比PIC12F675-I/MF)
- 4x more code space on a same-footprint upgrade path (對比PIC12F1840-E/MF)
- Extended temperature grade in identical DFN-8 package (對比PIC12F635-E/MF)
設計說明
Decouple VDD (pin 1) with a 100 nF X7R ceramic placed within 3 mm of the package, plus a 4.7-10 uF bulk capacitor on the upstream rail. The PIC12F635-I/MF draws ~100 uA/MIPS active and sub-1 uA in sleep, so a low-Iq LDO such as MCP1700 is recommended for battery-powered designs. Estimated: at 20 MHz active with 5V VDD the core draws ~2 mA; verify with the PIC12F635 family datasheet power curves section.
Reserve GP3/MCLR (pin 4) for the ICSP programming header unless the internal MCLR disable configuration bit is set, in which case GP3 becomes a general-purpose input. Route the ICSP header to a 5-pin 0.1-inch header footprint so the PICkit can be attached without disassembly. The 8-pin DFN has an exposed pad (EP) on the underside that should be soldered to the PCB ground pour for thermal dissipation and mechanical strength.
Keep the ICSP traces short and away from switching nodes; if the design includes an analog front-end driven by the on-chip comparator, route CIN+ and CIN- (pins 6 and 7) as a differential pair with a ground guard on either side. Avoid running high-current traces under the DFN-8 thermal pad to prevent ground-bounce coupling into the analog comparator reference. Use a single ground pour stitched with vias around the MCU for low-impedance return paths.
Do not exceed 20 MHz Fosc below 4.5V VDD; the PIC12F635 datasheet's electrical characteristics specify that 20 MHz operation requires 4.5V-5.5V. Below 4.5V, Fosc derates to 10 MHz (2.0V-4.5V). Forgetting this is the most common cause of erratic behavior at low battery voltage. Also remember that the PIC12F635 has no ADC; do not connect analog sensors to GP0-GP5 expecting ADC readings - use the enhanced comparator or migrate to PIC12F675/PIC12F683 if an ADC is required.
When using the internal comparator for PIR or thermopile sensing, add a small RC low-pass filter on the comparator input to suppress switching-noise spikes from nearby digital lines. The comparator output (COUT on GP2) can be configured as an interrupt source to wake the MCU from sleep, which is essential for battery-powered motion detectors. Keep the comparator input traces short and surrounded by ground to minimize pickup from the ICSP clock line.
合規資訊
RoHS compliant per Microchip material declaration. AEC-Q100 not qualified - choose PIC12F635-E/MF for extended temperature or PIC16F1xxx AEC-Q100 variants for automotive. Halogen-free status not explicitly stated in retrieved data.
