Microchip Technology RFPIC12F675FT-I/SS

Overview

RFPIC12F675FT-I/SS from Microchip Technology is a FLASH-based 8-bit RISC microcontroller with integrated UHF ASK/FSK transmitter, operating at 380–450 MHz. It features 1024 × 14 words of program memory, 128 bytes of EEPROM, 10-bit ADC with 4 channels, and 6 GPIO pins with interrupt-on-change. Used in automotive remote keyless entry (RKE) systems requiring compact, low-power wireless control.

For engineers reviewing the RFPIC12F675FT-I/SS datasheet, RFPIC12F675FT-I/SS pinout, RFPIC12F675FT-I/SS application, or RFPIC12F675FT-I/SS equivalent, key selection considerations include its integrated RF transmitter architecture, 20-pin SSOP package, 4 MHz internal oscillator calibrated to ±1%, ASK/FSK modulation support up to 40 Kbps, and FCC Part 15.231/EN 300 220 compliance.

Technical Context

The RFPIC12F675FT-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 RF section operates independently from the MCU core, enabling concurrent baseband processing and RF transmission.

It supports dual modulation schemes: ASK via DATAASK pin and FSK via DATAFSK/FSKOUT pins, with output power adjustable across four levels (+10 dBm to –12 dBm). The REFCLK output provides divided crystal reference (÷4 for K/F variants, ÷8 for H variant), confirming RFPIC12F675FT-I/SS is the 380–450 MHz FSK/ASK variant ('F' suffix).

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with rfPIC12F629-I/SS and STM8L152C6T6, RFPIC12F675FT-I/SS uniquely combines certified RF transmission, 8-bit RISC efficiency, and sensor peripherals in one SSOP package - reducing bill-of-materials, certification risk, and time-to-market for fixed-band sub-GHz wireless controllers.

Availability

RFPIC12F675FT-I/SS is available at Aetrix Electronics and suitable for automotive RKE systems, wireless alarm peripherals, and battery-powered telemetry requiring stable component supply and long-lifecycle support.

Supply support for RFPIC12F675FT-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, analog, and FPGA solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

RFPIC12F675FT-I/SS belongs to Microchip's legacy rfPIC® family - designed specifically for cost-sensitive, battery-operated sub-GHz wireless control applications where integration, regulatory compliance, and small footprint are critical.

FAQ

What RF frequency band does the RFPIC12F675FT-I/SS operate in?

The RFPIC12F675FT-I/SS operates in the 380–450 MHz UHF band, as indicated by the 'F' suffix in its part number per Microchip's identification system. This matches FCC Part 15.231 and EN 300 220 regulations for license-free short-range devices. Its RF carrier is generated by multiplying the external RFXTAL crystal frequency by 32 - for example, a 12.5 MHz crystal yields 400 MHz output. RFPIC12F675FT-I/SS does not support 290–350 MHz ('K') or 850–930 MHz ('H') bands.

Does the RFPIC12F675FT-I/SS require an external RF power amplifier?

No, the RFPIC12F675FT-I/SS integrates a fully functional RF power amplifier with adjustable output power (+10 dBm to –12 dBm in 4 steps) and RFEN enable control. It drives the ANT pin directly into a 50 Ω load, though an external matching network is required for optimal power transfer and harmonic suppression per band. RFPIC12F675FT-I/SS eliminates the need for discrete PA stages, reducing BOM cost and board space.

How is the RFPIC12F675FT-I/SS programmed in-circuit?

The RFPIC12F675FT-I/SS supports In-Circuit Serial Programming (ICSP™) using two dedicated pins: GP0/ICSPDAT (pin 19) and GP1/ICSPCLK (pin 18). A standard Microchip PIC programmer applies VPP (~13 V) to GP3/MCLR (pin 4) while toggling clock and data lines. RFPIC12F675FT-I/SS does not require full socket removal - firmware updates can be performed on assembled PCBs, enabling field upgrades and post-production calibration.

What is the purpose of the REFCLK pin on the RFPIC12F675FT-I/SS?

The REFCLK pin (pin 7) outputs a divided version of the RFXTAL crystal frequency - specifically ÷4 for the RFPIC12F675FT-I/SS ('F' variant). This 3–11.25 MHz clock can serve as a precise system timing reference for the MCU core or synchronize external receiver circuitry. Unlike generic clock outputs, REFCLK is derived from the same crystal driving the RF synthesizer, ensuring phase coherence between baseband and RF domains in RFPIC12F675FT-I/SS designs.

Can the RFPIC12F675FT-I/SS operate from a single 3.3 V supply?

Yes, the RFPIC12F675FT-I/SS supports a wide operating voltage range of 2.0–5.5 V, making it compatible with 3.3 V logic systems. However, note that VDD (digital supply) and VDDRF (RF supply) are separate pins (pins 4 and 9) - both must be supplied at the same nominal voltage (e.g., 3.3 V) for proper operation. Operating RFPIC12F675FT-I/SS at 3.3 V reduces RF output power slightly versus 5 V but maintains full functionality and meets specified current consumption metrics.