A sub-1µW, 16kHz Current-Mode SAR-ADC for Neural Spike Recording
This thesis presents an ultra-low-power 8-bit asynchronous current-mode
successive approximation (SAR) ADC for single channel neuron spike recording.
The novel design exploits current mode operating in weak inversion for
high power efficiency and is designed to operate at a 1.8V supply. The ADC is
running at a 16kHz sampling frequency using under 1uW of power, though
is adjustable using the featured calibration registers. A finished layout is
presented, occupying less than 0.078mm2. Linear operation through mismatch
and process variations is obtained using a current calibration circuit
connected to both the current mode DAC and all the biases. This ensures
INL < 0.5 and DNL < 1, yielding no missing codes and a 3sigma production
yield. Calibration is needed because of the relatively large mismatch caused
by sub-threshold operation of the current mirrors. The design also offers a
newly developed current comparator with high resolution and fast settling
relative to the current level and is completable with other state-of-the-art solutions,
though still feature some voltage scaling issues left for future work.
Place, publisher, year, edition, pages
Institutt for elektronikk og telekommunikasjon , 2011. , 113 p.
ntnudaim:6286, MTEL elektronikk, Analog og blandet design
IdentifiersURN: urn:nbn:no:ntnu:diva-14371Local ID: ntnudaim:6286OAI: oai:DiVA.org:ntnu-14371DiVA: diva2:452319
Ytterdal, Trond, ProfessorConstandinou, Timothy