Patent ID: 6359475
Filing Date: 2002-03-19
Classification: G11C

Abstract:
A sample and hold circuit, comprising:a first operational amplifier having first and second inputs and an output; a second operational amplifier having first and second inputs, and first and second outputs, wherein the first input is connected to the output of the first operational amplifier, the second input is connected to the second input of the first operational amplifier, and the first and second outputs are adapted for connection to an analog-to-digital converter; a first switch adapted for connection to an input voltage; a second switch adapted for connection to a ground reference; third and fourth switches adapted for connection to a voltage reference; a fifth switch connected in a first feedback loop between the first input and first output of the second operational amplifier; a sixth switch connected in a second feedback loop between the second input and second output of the second operational amplifier; a first capacitor connected between the first switch and the first input of the first operational amplifier; and a second capacitor connected between the second switch and the second input of the first operational amplifier; wherein, the first switch is connected between the voltage reference and the first capacitor; the second switch is connected between the ground reference and the second switch; the third switch is connected between the voltage reference and the first input of the first operational amplifier; and the fourth switch is connected between the voltage reference and the second input of the first operational amplifier.