Design of a High Voltage Linear Regulator with Current Sinking Capability for Capacitive Micromachined Ultrasonic Transducer Driver Circuit

This work presents a high voltage linear regulator for integration in the power management unit of a capacitive micromachined ultrasonic transducer driver circuit. A novel topology of a linear regulator with high current sinking capability, which transforms an input voltage of 70 V into a stable output voltage of 66 V, was developed. The physical layout was created and occupies a die area of 0.15 mm2. The functionality was evaluated through post-layout simulations for 16 corners and temperature extremes of −40 C and 100 C. Typically, the regulator is able to maintain an output voltage of 65.75 V when sinking every 500 ns load current pulses with a magnitude of 100 mA, 35 ns width and 3 ns rise and fall time. The total quiescent current is 288 mA. The regulator exhibits line regulation of 90 mV/V and a load regulation of 1.7 mV/mA. Power efficiency of 94.01 % could be achieved. The project is realized in a high-voltage 0.18 mm silicon on insulator (SOI) process from X-FAB Silicon Foundries SE. The BSIM3v3 model has been used for circuit simulations in the Spectre Simulator from Cadence Design Systems Inc..