Print Email Facebook Twitter An Auto-Zero-Stabilized Voltage Buffer With a Quiet Chopping Scheme and Constant Sub-pA Input Current Title An Auto-Zero-Stabilized Voltage Buffer With a Quiet Chopping Scheme and Constant Sub-pA Input Current Author Rooijers, C.T. (TU Delft Electronic Instrumentation) Huijsing, J.H. (TU Delft Electronic Instrumentation) Makinwa, K.A.A. (TU Delft Microelectronics) Department Microelectronics Date 2022 Abstract This article describes an auto-zero stabilized voltage buffer that achieves low offset and low noise with sub-pA input current. A high gain stabilization loop is used to periodically cancel the buffer’s offset. The loop itself is periodically disconnected from the buffer and auto-zeroed, during which its bandwidth is reduced to reduce the associated noise folding. However, this also reduces its offset correction range, and so to avoid overloading, its initial offset is digitally trimmed. To break up the correlation between the residual low-frequency (LF) noise of the auto-zero and stabilization phases, the loop is periodically chopped, which significantly reduces the buffer’s LF noise. Finally, the duty-cycle of the two phases is optimized to bring the buffer’s LF noise density close to 2–√ times its white noise density (14 nV/ Hz−−−√ ), which is the fundamental limit of an AZ amplifier. The buffer also achieves a constant and low input current (0.8 pA), as well as a state-of-the-art offset (0.4 μV ). Subject Auto-zerodigitally assisted AZ looplow input currentlow offsetnoise correlationnoise folding To reference this document use: http://resolver.tudelft.nl/uuid:af37d4fe-ebba-4ae2-854b-7dafb98a897d DOI https://doi.org/10.1109/JSSC.2021.3127462 Embargo date 2023-02-08 ISSN 0018-9200 Source IEEE Journal of Solid State Circuits, 57 (8), 2438-2448 Bibliographical note Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public. Part of collection Institutional Repository Document type journal article Rights © 2022 C.T. Rooijers, J.H. Huijsing, K.A.A. Makinwa Files PDF An_Auto_Zero_Stabilized_V ... urrent.pdf 3.29 MB Close viewer /islandora/object/uuid:af37d4fe-ebba-4ae2-854b-7dafb98a897d/datastream/OBJ/view