The ATA5282 is a 125-kHz ultra low power receiver IC with three input channels for Passive Entry Go applications. It includes all circuits for an LF wake-up channel. The three sensitive input stages of the IC amplifier demodulate and measure the input signal from the antenna coils. The microcontroller interface of the IC outputs the data signal as well as the measured RSSI values. During standby mode, the header detection unit monitors the incoming signal and generates a wake-up signal for the microcontroller if the IC receives a valid 125-kHz carrier signal. By combining the IC with an antenna coil, a microcontroller, an RF transmitter/transceiver and a battery, it is possible to design a complete hands-free key for Passive Entry Go applications.