公开(公告)号：US20180367065A1

公开(公告)日：2018-12-20

申请号：US16061966

申请日：2017-01-06

Applicant: Polight AS

Inventor： Tore SVORTDAL

IPC: H02N2/06 ,  H02N2/02 ,  G02B26/08

Abstract: The invention relates to an electronic circuit (100) for controlling charging of a piezoelectric load (190). The electronic circuit comprises a charge pump (111) configured to supply a charging current to the piezoelectric load dependent on a charge control signal (131), a measurement circuit (113) configured to obtain a load voltage corresponding to a terminal voltage at a load terminal of the piezoelectric load, a comparator circuit (114) configured to compare an adjustable reference voltage with the load voltage. The electronic circuit is configured to determine the charge control signal dependent on the comparison so that the control signal controls delivery of the charging current dependent on the comparison. The electronic circuit is further configured to set the adjustable reference voltage to a target voltage (VT) and to set the adjustable reference voltage to a low limit voltage (Vlow), being lower than the target voltage, when the load voltage reaches the target voltage.