Patent ID: 8405375
Filing Date: 2013-03-26
Classification: G11C

Abstract:
1. A circuit for providing a reference voltage, comprising: a bandgap reference circuit operable to provide a first reference voltage; a first unity gain buffer coupled to the bandgap reference circuit operable to provide a second reference voltage at a second reference voltage node from the first reference voltage; a first switch for passing the second reference voltage between the second reference voltage node and a third reference voltage node; a first capacitor coupled to the third reference voltage node; a second switch coupled between the third reference voltage node and a fourth reference voltage node; a second capacitor coupled to the fourth reference voltage node, wherein during operation a fourth reference voltage at the fourth reference voltage node decays when the second capacitor discharges; and a control circuit operable to provide control signals to intermittently activate the bandgap reference circuit, first unity gain buffer and first switch to charge the first capacitor, to disconnect the third and fourth reference voltage nodes during charging of the first capacitor and to connect the third and fourth reference voltage nodes following charging of the first capacitor, thereby increasing the fourth reference voltage following decay thereof.