The implementation of future instruments for capturing neural activity in the brain requires data acquisition with good noise immunity, high resolution and extremely low levels of power consumption. A/D converters based on sigma-delta modulation are especially well suited to achieving the resolution requirements expected for such systems. However, in array configurations of conventional oversampling modulators, the attendant power dissipation seems likely to exceed the requirements foreseen for neural imaging applications. The immediate purpose of this research is to find novel architectural techniques for power reduction - such as signal multiplexing and stage-sharing. Low-power circuit implementations, such as those based on subthreshold circuit design, will also be investigated.
Integrated Circuits Lab