RFM75-S

General Description

RFM75 is a GFSK transceiver operating in the world wide ISM frequency band at 2400-2483.5 MHz.Burst mode transmission and up to 2Mbps air data rate make them suitable for applications requiring ultra low power consumption. The embedded packet processing engines enable their full operation with a very simple MCU as a radio system. Auto re-transmission and auto acknowledge give reliable link without any MCU interference. 
RFM75 operates in TDD mode, either as a transmitter or as a receiver.
The RF channel frequency determines the center of the channel used by RFM75. The frequency is set by the RF_CH register in register bank 0 according to the following formula: F0= 2400 + RF_CH (MHz). The resolution of the RF channel frequency is 1MHz.
A transmitter and a receiver must be programmed with the same RF channel frequency to be able to communicate with each other. The output power of RFM75 is set by the RF_PWR bits in the RF_SETUP register. 
Demodulation is done with embedded data slicer and bit recovery logic. The air data rate can be programmed to 250Kbps, 1Mbps or 2Mbps by RF_DR_HIGH and RF_DR_LOW register. A transmitter and a receiver must be programmed with the same setting.
In the following chapters, all registers are in register bank 0 except with explicit claim.

Features

• 2400-2483.5 MHz ISM band operation
• Support 250Kbps, 1Mbps and 2 Mbps airdata rate
• Programmable output power
• Tolerate +/- 60ppm 16 MHz crystal
• Variable payload length from 1 to 32bytes
• Automatic packet processing
• 6 data pipes for 1:6 star networks
• 1.9V to 3.6V power supply
• 4-pin SPI interface with maximum 8 MHz clock rate
• 20-pin 4x4mm QFN package

Applications

• Wireless PC peripherals
• Wireless gamepads
• Wireless audio
• Remote controls
• Home automation
• Toys