Prototype silicon micropower supply for sensors

Miniature, remote, autonomous sensors generally have a relatively large power supply compared to the size of the sensor and sensor conditioning electronic circuitry. An integrated micropower supply made in a silicon wafer offers the prospect of shrinking the power supply size down to the size of the sensor and conditioning circuitry. In this paper, we describe a prototype silicon micropower supply comprising a nickel-zinc microbattery integrated in a silicon wafer interfaced to a miniature silicon solar array via an adaptable charge controller that can optimally supply charging current from the miniature solar array to the microbattery. Details of each of the subsystems are described together with test results on a multichip, hybrid implementation of an all-silicon, miniature power supply.