Patent ID: 9250271
Filing Date: 2016-02-02
CPC Classification: G01R,G05F,G06F,H02M

Claim Text:
1. A direct voltage sensor for a computer circuit, comprising: a sensor resistor having a first end and a second end; a current source having an source input directly connected to the second end of the sensor resistor and a source output, the current source configured to drive a sensor current through the sensor resistor; a differential op-amp comprising a first input directly connected to the source input of current source and the second end of the sensor resistor, and a second input directly connected to the first end of the sensor resistor, the differential op-amp configured to receive a voltage drop across the sensor resistor caused by the sensor current, the second input connected to a pump voltage source to receive a pumped voltage, wherein the differential op-amp further comprises an output reflecting a difference between voltage levels on the first and second inputs; a feedback connection from the op-amp output directly to the current source configured to control the current source to drive the sensor current; wherein the first end of the sensor resistor is configured to receive a feedback signal directly from the pump voltage source included in a charge pump system generating the pumped voltage; wherein the second end of the sensor resistor is configured to generate a comparison voltage representative of the pumped voltage as the pumped voltage experiences a voltage drop resulting from depletion of electric charge stored by a capacitor of the charge pump; and wherein the differential op-amp is configured to drive the sensor current to cause the voltage drop across the sensor resistor to remain constant as the pumped voltage experiences the voltage drop.