Power Management Techniques for Very Low Consumption and EMI Reduction in Automotive Applications

An event driven synchronous clock state machine scheme has been developed in BiCMOS technology. The proposed implementation uses a voltage and clock system management approach where the circuit works trigged by events, saving power and reducing EMI. A comparison between standard methods using continuous clock and the proposed implementation is presented. This implementation was used into a high speed CAN transceiver device contributing to low power consumption (96uW in sleep and 120uW in standby operating mode) and achieves low EMI under CAN bus idle condition and during transmission (under 40dBuV in the 1 MHz to 1 GHz range). A theoretical analysis and silicon measurements are presented and discussed.