SI4455-B1A-FM

SI4455-B1A-FM is a Silicon Labs RF transceiver IC (Si4455 family) designed for low‑power wireless in ISM/license‑free bands. It integrates the RF front end (PA, LNA, mixer), a programmable frequency synthesizer, and a digital baseband/modem, all controllable via SPI.
Key points:
- Modulation and data: supports common schemes (FSK/GFSK, MSK, GMSK, OOK/ASK), flexible data rates, and built‑in packet handling (CRC, address filtering) with RSSI/readout of link quality.
- Power and interface: low‑power operation with multiple power modes, adjustable TX output power, single‑supply operation, and a simple SPI interface with GPIOs.
- Packaging/revision: B1A-FM denotes a specific package/revision; check the datasheet for exact band coverage, electrical specs, and recommended applications.
- Applications: remote controls, wireless sensors, meters, home/industrial IoT, and other low‑power wireless links.
For exact RF bands, power, and feature support, consult the SI4455‑B1A‑FM datasheet and programming guide.

Here are the key features of the SI4455-B1A-FM (Si4455 family):
- Sub-GHz RF transceiver for ISM bands with integrated PLL/VCO
- Modulation: FSK/GFSK, and OOK/ASK
- Data rate: up to several hundred kbps
- Programmable TX output power (high efficiency, up to ~+20 dBm)
- Receiver sensitivity in the wide range of tens of dBm below 0 dBm (typical around -110 to -120 dBm)
- Integrated RF frontend, RSSI, AFC, and channel filtering
- Universal 1.8–3.6 V supply; low-power operation with configurable power-saving modes
- SPI control interface with multiple GPIOs/DIOs and interrupt support
- Small footprint packaging suitable for embedded systems (FM/B1A variants)
- Suitable for remote controls, sensors, metering, and other sub-GHz wireless applications
Note: exact frequency coverage, data rate, and TX power depend on the chosen band and external components; consult the datasheet for precise numbers for your configuration.

Pin count: 20 pins in a 4x4 mm QFN package (SI4455-B1A-FM).
Function: EZRadioPro sub‑GHz RF transceiver. Pins include RF_P/RF_N for the RF front end, power (VDD/GND), SPI control lines (SI, SO, SCLK, NSEL), Shutdown (SDN), four GPIOs (GPIO0–GPIO3) and event/interrupt lines (GDO/NIRQ).

- Manufacturer: Silicon Laboratories, Inc. (Silicon Labs).
- What kind of company: A fabless semiconductor company that designs and markets silicon, software, and solutions for IoT, including RF transceivers, wireless MCUs, timing products, and related ICs.

SI4455-B1A-FM is a low-power, highly integrated transceiver for sub-GHz ISM bands (roughly 240–960/300–928 MHz). Common application areas include:
- Home/building automation (sensors, actuators, remote controls)
- Industrial automation and process telemetry
- Smart metering and utility telemetry
- Asset tracking, inventory management, and logistics
- Remote monitoring and data acquisition (environmental, HVAC)
- IoT sensor networks and gateways
These use cases leverage its long-range, low-power wireless links in the ISM bands.

QFN (Quad Flat No-Lead) package, typically a 20‑pin 4×4 mm QFN.