Linear CMOS power controller for precision sensor applications

The authors describe the design and implementation of a controlled power source. Its function is to stabilize power over a reasonable range of load variations. A solution using only linear circuit blocks is proposed in order to avoid an analog multiplier. This is achieved by making the power regulation around the nominal operating point and keeping only the first order correcting terms in the compensation equation. The error introduced by this approach is smaller than 0.2% for 10% load variation, which gives a stabilization factor of 50. The circuit was integrated as a driver for the resistor heating element of an air flow sensor cointegrated on the same chip