Method and apparatus for micropower analog-to-digital conversion in an implantable medical device
US5606320A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 6, 1994 |
| Grant date | Feb 25, 1997 |
| Priority date | — |
| Expiry date | Dec 6, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/466
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A micropower analog-to-digital converter (ADC) for use in an implantable medical device is disclosed. The ADC achieves a high conversion speed at micropower levels through a number of timing and circuit improvements over the conventional implementation of the successive approximation ADC architecture. The ADC includes a digital-to-analog converter (DAC) that preferably is implemented as a binary-weighted, switched capacitor array that employs top plate charging and performs bipolar conversion. The DAC provides an analog output signal representing array charge to a comparator. During a comparator latch phase, the DAC asynchronously determines a bit of the ADC digital output signal in response to the comparator output, and initiates a test of the next least significant bit during the same latch phase. Further, the DAC analog output signal is timed to settle during the latch phase in response to both the bit update and the next bit test. In conjunction with increasing conversion speed, the DAC reduces power requirements by using a power gated buffer that selectively increases the power of the ADC input signal only when necessary to drive the ADC conversion circuitry. Further, the comp…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.