A fully integrated CMOS PM radio receiver for wristwatch calibration

In this paper, a fully integrated phase modulation radio receiver ASIC is presented. The ASIC is a mixed analog and digital circuit, implemented in a 1.5-/spl mu/m CMOS technology. The only required external components are the reception antenna and a 32-kHz crystal. The radio receiver is dedicated to the 162-kHz "Allouis" radio transmitter. In addition to the audio information, 40-bit/s digital data are transmitted as phase modulation of the main carrier. These digital data may contain "live" information, such as the exact time. The presented ASIC demodulates and decodes these digital data. The principal features of this radio receiver are a low voltage supply (2.2-4.5 V), low power consumption (less than 150 /spl mu/A), a large sensitivity range (10 /spl mu/V-100 mV), and a reduced number of external components. Thanks to all of these performances, the circuit can be built in a wristwatch.