The RFM66W is a fully integrated ISM band transceiver optimized for use in the (EN 300 220-1) 868 MHz band in Europe and the (FCC Part 15) 915 MHz band in the US with a minimum of external components. It offers a combination of high link budget and low current consumption in all operating modes. The 143 dB link budget is achieved by a low noise CMOS receiver front end and up to +20 dBm of transmit output power. A pair of internal power amplifiers are provided permitting either fully regulated - for constant RF performance, or direct supply connection - for optimal efficiency. This makes RFM66W ideal for either M2M applications powered by alkaline battery chemistries or long battery life metering applications using Lithium battery chemistries. The Low-IF architecture of the RFM66W sees fast transceiver start times and demodulation predicated towards low modulation index and gaussian filtered spectrally efficient modulation forma