High-Voltage Hall-Effect Sensor Interface in a Standard Digital CMOS Process

A high-voltage Hall-effect sensor interface realized in a 5V 0.6 mum CMOS process using 40V high-voltage devices is presented. The design includes a high-voltage operational transconductance amplifier, which achieves a common-mode input range that is within a V_TP of the upper rail with the use of a bulk-driven input stage. Also discussed is a reverse voltage protection architecture that uses a comparator with a bulk-driven input stage and a PMOS blocking technique. These reverse voltage blocks allow for a reliable reverse battery protection without using a series blocking diode or resistor. Integration of these blocks into a standard CMOS process allows for cost savings as additional devices such as data converters and microprocessors are combined with the Hall-effect sensor interface