Microchip Technology RFPIC12F675F-I/SS

Overview

RFPIC12F675F-I/SS from Microchip Technology is a FLASH-based 8-bit RISC microcontroller with integrated UHF ASK/FSK transmitter, operating in the 380–450 MHz band. It features 1024 × 14 words of FLASH program memory, 128 bytes of EEPROM, 10-bit ADC with 4 channels, and on-chip 4 MHz precision oscillator calibrated to ±1%. It is used in automotive remote keyless entry (RKE) systems requiring compact, low-power wireless control.

For engineers reviewing the RFPIC12F675F-I/SS datasheet, RFPIC12F675F-I/SS pinout, RFPIC12F675F-I/SS application, or RFPIC12F675F-I/SS equivalent, key selection considerations include its integrated RF transmitter architecture, 20-pin SSOP package, 380–450 MHz frequency band compliance with FCC Part 15.231 and EN 300 220, and dual modulation support (ASK/FSK up to 40 kbps).

Technical Context

The RFPIC12F675F-I/SS integrates a PICmicro Mid-Range core with dedicated RF front-end circuitry including VCO, loop filter, power amplifier, and crystal oscillator multiplier (×32). Its RFEN pin enables hardware-controlled transmit activation, while REFCLK provides divided crystal reference output for external synchronization.

It supports three oscillator modes: internal 4 MHz INTOSC, external crystal (DC–20 MHz), and RC (DC–4 MHz). The RF section uses RFXTAL input at fundamental frequency (e.g., 13.56 MHz for 434 MHz output), with phase-locked VCO ensuring narrow-band transmission suitable for interference-immune receivers.

Key Specifications

Pinout & Package

Package: 20-pin SSOP (Small Outline Package), 0.65 mm pitch, body width 5.3 mm - suited for space-constrained PCB layouts in key fobs and sensors.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF microcontroller applications.

Compared with PIC16F631-I/SS, RFPIC12F675F-I/SS delivers full RF system integration in one die, eliminating external RF components and reducing PCB area by >40%. Compared with CC1110F32RHHR, it targets lower-cost, lower-power 380–450 MHz applications compliant with legacy RKE standards rather than 2.4 GHz protocols.

Availability

RFPIC12F675F-I/SS is available at Aetrix Electronics and suitable for automotive RKE systems, wireless sensor nodes, and garage door opener transmitters requiring stable component supply across long-lifecycle industrial programs.

Supply support for RFPIC12F675F-I/SS includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology Inc. is a leading provider of microcontroller, mixed-signal, analog, and Flash-IP solutions, headquartered in Chandler, Arizona.

The rfPIC12F675 product line was designed specifically for ultra-compact, battery-operated wireless transmitter applications in the sub-GHz ISM bands, emphasizing integration, low quiescent current, and regulatory compliance.

FAQ

What is the operating frequency range supported by the RFPIC12F675F-I/SS?

The RFPIC12F675F-I/SS operates in the 380–450 MHz frequency band, optimized for regional ISM allocations such as 433.92 MHz in Europe and 433.5–434.5 MHz in other jurisdictions. Its internal ×32 frequency multiplier locks the VCO to the fundamental crystal input (e.g., 13.56 MHz), ensuring stable, narrow-band transmission compliant with FCC Part 15.231 and EN 300 220.

Does the RFPIC12F675F-I/SS require an external crystal for RF operation?

Yes, the RFPIC12F675F-I/SS requires an external fundamental-mode crystal connected to the RFXTAL pin. For 434 MHz operation, a 13.56 MHz crystal is used; the internal PLL multiplies this by 32. The crystal must meet load capacitance and stability specifications outlined in Section 15.0 of the DS70091B datasheet to maintain frequency accuracy and regulatory compliance.

How many analog input channels does the RFPIC12F675F-I/SS support?

The RFPIC12F675F-I/SS supports four analog input channels (AN0–AN3) mapped to GP0, GP1, GP2, and GP4. These feed a 10-bit successive-approximation ADC with internal voltage reference options, enabling direct measurement of sensor signals such as battery voltage, thermistor resistance, or pressure transducer outputs in wireless endpoint applications.

What is the purpose of the REFCLK pin on the RFPIC12F675F-I/SS?

The REFCLK pin on the RFPIC12F675F-I/SS outputs a divided version of the RF crystal frequency - specifically CLK/4 for the RFPIC12F675F variant. This signal provides a stable, low-jitter timing reference for synchronizing external circuitry, such as a companion receiver IC or baseband logic, improving demodulation reliability and reducing system-level timing drift in bidirectional or time-critical wireless links.

Can the RFPIC12F675F-I/SS be programmed in-circuit after soldering to the PCB?

Yes, the RFPIC12F675F-I/SS supports In-Circuit Serial Programming (ICSP) using GP0 (ICSPDAT) and GP1 (ICSPCLK) pins. This allows firmware updates, calibration data writing, or security key provisioning without removing the device from the assembled board - essential for high-volume manufacturing test and field maintenance of RFPIC12F675F-I/SS-based products.