CAPACITIVE DIGITAL-TO-ANALOG CONVERTER RESET IN AN IMPLANTABLE MEDICAL DEVICE ANALOG-TO DIGITAL CONVERTER

摘要

In general, this disclosure describes techniques for capacitive digit-to-analog converter (CAPDAC) resetting in an implantable medical device (IMD) analog-to-digital converter (ADC). The CAPDAC of an IMD ADC may occasionally be reset to increase the accuracy of its output. The output of the CAPDAC may be disconnected from a negative feedback input of an integrator and connected to a pseudo load during the reset. Disconnecting the CAPDAC from the negative feedback input of the integrator reduces the affect of the reset on the integrator. During the reset of the CAPDAC, the negative feedback input of integrator is coupled to a sample and hold capacitor, which temporarily provides an input approximately equal to a previous, e.g., immediate, value of the output of CAPDAC prior to the reset. Thus, the resetting of the CAPDAC is done in such a manner that the affect of the reset on integrator is substantially reduced or eliminated.