Patent ID: 6263192
Filing Date: 2001-07-17
Classification: H02M,H04B,H04L

Abstract:
A mobile communications device comprising:a DC power supply for providing a first DC output voltage;a DC--DC converter having a synchronization input and configured to receive the first DC output voltage and produce, responsive to a switching waveform generated by a first internal clock, a second DC output voltage for powering components of the communications device;a transceiver coupled to an antenna having a frequency band;a baseband circuit having a signal line coupled to the transceiver;a microprocessor coupled to the baseband circuit through at least one signal line; anda UART coupled to the microprocessor having a second variable frequency transmit clock output coupled to the synchronization input of the DC--DC converter, with the second clock set at a frequency determined appropriate for synchronization of the first clock and to avoid substantial interference with the frequency band of the transceiver, whereby synchronization of the first clock by the second clock is achieved.