Microchip Technology RFPIC12F675HT-I/SS

Overview

rfPIC12F675HT-I/SS from Microchip Technology is a FLASH-based 8-bit RISC microcontroller with integrated UHF ASK/FSK transmitter, operating at 434 MHz (H-band variant), featuring 1024 × 14-bit FLASH, 128-byte EEPROM, 10-bit ADC with 4 channels, and 6 GPIO pins with interrupt-on-change. It delivers +10 dBm to –12 dBm RF output power in 4 steps for automotive RKE and wireless sensor applications.

For engineers reviewing the rfPIC12F675HT-I/SS datasheet, rfPIC12F675HT-I/SS pinout, rfPIC12F675HT-I/SS application, or rfPIC12F675HT-I/SS equivalent, key selection considerations include its SSOP-20 package, factory-calibrated 4 MHz internal oscillator (±1%), integrated VCO/loop filter/power amp, FCC Part 15.231 and EN 300 220 compliance, and low-power sleep current of 0.1 µA.

Technical Context

The rfPIC12F675HT-I/SS integrates a PICmicro Mid-Range core with 35 single-cycle instructions and an 8-level hardware stack, paired with a fully integrated UHF transmitter subsystem including crystal oscillator (RFXTAL), phase/frequency detector, charge pump, VCO, loop filter (LF), and RF power amplifier driving ANT via VDDRF/VSSRF rails. Its RFEN pin enables/disables transmission, while DATAASK and DATAFSK accept baseband modulation inputs.

It supports dual-domain operation: digital core runs from VDD (2.0–5.5V) with 500 µA typical active current at 4 MHz INTOSC, while RF section operates from dedicated VDDRF with independent VSSRF ground references and REFCLK output (divided-by-4 on K/F variants, divided-by-8 on H variants). The device uses GP0–GP5 for mixed-signal I/O, including analog comparator (16 reference levels), Timer0/Timer1, and ICSP programming via GP0/GP1.

Key Specifications

Pinout & Package

rfPIC12F675HT-I/SS is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm pitch, optimized for compact RF PCB layouts requiring separate analog/digital/RF ground domains.

Key Features

Applications

Equivalent & Alternatives

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

Compared with rfPIC12F675F-I/SS and rfPIC12F675K-I/SS, the rfPIC12F675HT-I/SS provides higher-frequency operation (850–930 MHz), enabling smaller antennas and better immunity to narrowband interference in dense urban deployments - critical for next-generation smart building access systems.

Availability

rfPIC12F675HT-I/SS is available at Aetrix Electronics and suitable for automotive RKE systems, wireless sensor nodes, and industrial telemetry applications requiring stable component supply, long-lifecycle support, and regulatory-ready RF integration.

Supply support for rfPIC12F675HT-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, with global design and manufacturing operations.

The rfPIC12F675 product line was designed to integrate RF transmission capability directly into cost-sensitive 8-bit microcontrollers for short-range wireless control - targeting automotive, security, and metering applications where minimal external components and regulatory compliance are mandatory.

FAQ

What is the RF frequency band supported by the rfPIC12F675HT-I/SS?

The rfPIC12F675HT-I/SS operates in the 850–930 MHz band (H-band), with transmit frequency determined by the external crystal connected to RFXTAL and multiplied by 32. This makes it suitable for EN 300 220-compliant applications in the 868/915 MHz ISM bands. The rfPIC12F675HT-I/SS does not support 315 MHz or 433 MHz bands - those require the K- or F-band variants respectively.

Does the rfPIC12F675HT-I/SS require an external crystal for RF operation?

Yes, the rfPIC12F675HT-I/SS requires an external fundamental-mode quartz crystal connected to RFXTAL to generate its RF carrier. The internal circuitry multiplies this crystal frequency by 32 to achieve the final UHF output. However, the digital core can run from its factory-calibrated 4 MHz internal oscillator, eliminating the need for a second crystal.

How many analog input channels does the rfPIC12F675HT-I/SS ADC support?

The rfPIC12F675HT-I/SS features a 10-bit analog-to-digital converter with four configurable input channels (AN0–AN3), mapped to GP0, GP1, GP2, and GP4 respectively. These channels support single-ended measurements with software-selectable voltage reference options, enabling direct interfacing with resistive sensors, thermistors, or battery monitoring circuits in the rfPIC12F675HT-I/SS system.

What is the purpose of the VDDRF and VSSRF pins on the rfPIC12F675HT-I/SS?

VDDRF and VSSRF provide a dedicated power and ground domain for the RF transmitter section - isolating sensitive analog RF circuitry from digital switching noise. VDDRF accepts 2.0–3.6V, while dual VSSRF pins (pins 10 and 12) must be connected to a clean, low-inductance RF ground plane. This separation is essential to meet spectral emission limits and maintain rfPIC12F675HT-I/SS transmit stability.

Can the rfPIC12F675HT-I/SS be programmed in-circuit after soldering?

Yes, the rfPIC12F675HT-I/SS supports In-Circuit Serial Programming (ICSP™) via GP0 (ICSPDAT) and GP1 (ICSPCLK), allowing full firmware programming and debugging without removing the device from the PCB. This capability is retained even when other GPIO functions are enabled, making the rfPIC12F675HT-I/SS ideal for field-upgradable wireless endpoints.