Full-Wave Current Sensor for Automotive Synchronous Buck Converter

This paper presents a novel current sensor suitable for fully integrated synchronous buck converters that operate over a wide range of input voltages, such as those used in automotive applications. Its topology was derived by addressing shortcomings of a solution published previously. A design example validates the proposal: the sensor implemented in a High-V 180nm CMOS process can operate with input voltages up to 45V, over a wide range off duty cycle values - between 10% and 70% - with errors smaller than 3% for inductor currents larger than 200mA.