A low-power CMOS front end for particle detection applications

A complete low-power front end for particle detection applications is proposed. The front end integrates a charge sensitive amplifier with a novel adaptive biasing scheme which allows the DC bias currents to be scaled below conventional limits. A peak detector circuit obtains a peak value for each detection event which is then converted to digital via an 8 bit charge-redistribution successive approximation analog to digital converter. The ADC is shut off in between detection events to further reduce power consumption. The entire circuit consumes between 39muW and 400muW of power depending on the particle detection rate. This low power operation enables the development of compact, long-life, battery powered, remote particle sensors.