KESTX01 is a single chip ASK (Amplitude Shift Key) transmitter IC. It is designed to operate in a variety of low power radio applications including keyless entry, general domestic and industrial remote control, RF tagging and local paging systems. The transmitter offers a high level of integration and performance, which enables the harmonic rejection and fundamental power requirements of the ESTI 300 220, and other governing bodies, to be met. The basic architecture utilises a crystal reference oscillator, an integrated frequency multiplying PLL and a power output stage. The design is centred around the popular 433.92 MHz operating frequency and particular emphasis has been placed on low current drain, including a power-down feature which greatly increases battery life.