Patent ID: 7623053

Claim:
An implantable medical device comprising: at least one sensor that generates an analog input signal; at least one delta-sigma analog-to-digital converter (ADC) that converts the analog input signal to a digital signal, the delta-sigma ADC comprising: an integrator that produces an integrated difference between the analog input signal and a reconstruction of the analog input signal; a quantizer that produces a control signal based on the integrated difference; an up/down counter that adjusts a digital value according to the control signal; a digital-to-analog converter (DAC) that generates the reconstruction of the analog input signal based on the digital value of the up/down counter and provides the reconstruction of the analog input signal as negative feedback to the integrator, wherein a resolution of the quantizer is less than a resolution of the DAC; and a compensation module that compensates for a phase shift in the negative feedback caused by the integrator and the up/down counter, wherein the device further comprises: a processor that receives the digital signal from the delta-sigma ADC.