Patent ID: 8115545

Claim:
A circuit comprising: a microelectromechanical structure configured to provide a current to a current path; an amplifier having a first input coupled to the current path, a second input configured to receive a first voltage, and an output configured to provide a second voltage; a first transistor coupled to the first input and the output of the amplifier; a second transistor having a gate configured to receive the second voltage and a source coupled to a first capacitive device; a first comparator having a first input configured to receive a third voltage at the source of the second transistor, a second input configured to receive a first reference voltage, and an output; a second comparator having a first input configured to receive the third voltage, a second input configured to receive a second reference voltage, and an output; a third transistor having a gate coupled to the output of the first comparator; a fourth transistor having a gate coupled to the output of the second comparator, and a drain coupled to a source of the third transistor and a gate of the first transistor; and a second capacitive device having one end coupled to the gate of the first transistor.