| CPC H03K 5/24 (2013.01) [G05F 1/56 (2013.01); H03K 5/02 (2013.01)] | 17 Claims |

|
1. An apparatus comprising:
a buffer amplifier having an output node;
a first current path between the output node and a capacitor, the first current path including a diode oriented with a cathode thereof toward the output node and further including a first switch between the output node and the capacitor;
a second current path between the output node and the capacitor, the second current path including a diode oriented with a cathode thereof toward the capacitor and further including a second switch between the output node and the capacitor; and
comparator circuitry operative, in response to a voltage on the capacitor being above an upper threshold, to open the first switch, wherein the comparator circuitry is further operative, in response to the voltage on the capacitor being below a lower threshold, to open the second switch.
|