Patent ID: 8013664
Filing Date: 2011-09-06
Classification: H02M,Y02B

Abstract:
1. A charge pump controller comprising: a configurable pump capacitor; a control circuit configured to couple the configurable pump capacitor in a charging configuration for a first time interval and to couple the configurable pump capacitor in a discharge configuration for a second time interval; a current source configured to provide a reference current; a charging circuit configured to form a charging current that is proportional to the reference current and to couple the charging current to the configurable pump capacitor to store a charge of a first value on the configurable pump capacitor responsively to the first time interval; and a discharge circuit configured to operate in a first state or a second state responsively to a first value of the reference current, the discharge circuit configured to limit charge coupled from the configurable pump capacitor to a load during the second time interval to approximately the first value responsively to the first state and to limit charge coupled from the configurable pump capacitor to the load during the second time interval to less than the first value responsively to the second state, the discharge circuit including a first current mirror configured to form a first current that is proportional to the reference current, a first transistor coupled to receive the first current responsively to the second time interval, and a second transistor that controls charge coupled from the configurable pump capacitor to the load to no greater than approximately the first value.