Improved current and charge amplifiers for driving piezoelectric loads

Piezoelectric transducers are known to exhibit less hysterisis when driven with current or charge rather than voltage. Despite this advantage, such methods have found little practical application due to the poor low frequency response of present current and charge driver designs. This paper introduces the compliance feedback current driver containing a secondary voltage feedback loop to prevent DC charging of capacitive loads and to compensate for any voltage or current offsets in the driver circuit. Low frequency bandwidths in the milli-Hertz range can be achieved.