Dr. Kishan Joshi

High power supply rejection over a wide frequency band is becoming a critical requirement for power regulators operating over increasingly higher bandwidths. With switching regulators shrinking in size and form factor, the reduction in passive filter sizes is further pushing operating frequencies higher in SoCs. Degraded power supply rejection in conventional linear and switching regulators and consequently higher ripple in the output supply domains these generate have the detrimental effect of impacting down-the-line blocks these regulators power. This manifests as limitation in the linearity of Analog-Digital converters, increased jitter in phase-locked loops which impacts overall SoC performance.

This talk will cover two aspects of improving robustness of supply regulator to power supple ripple. The first part of the talk focuses on improving the power supply rejection  (PSR) in a linear regulator which provides good PSR over a wide bandwidth. The talk will cover techniques to improve PSR without increasing the overhead on power consumption in the system. The second part of the talk will address commercial off-the-shelf (COTS) ripple cancellation system that can be used in conjunction with an existing switching regulator to suppress the ripple on the output of the system.

Biography:

Kishan Joshi received his M.S. & Ph.D. degrees in electrical engineering from Arizona State University, Tempe, AZ, USA in 2016 & 2020. He is currently working as an Analog Engineering Manager at Intel Corp., Santa Clara, CA on fully integrated voltage regulators.

Prior to joining Intel, Kishan has worked at Texas Instruments Inc. Tucson, AZ in the Linear Power group designing Low DropOut regulators from 2019 to 2021. He was an analog design intern at Kilby Labs, Texas Instruments, Santa Clara, CA in 2016, at NXP Semiconductors, Chandler, AZ in 2017 and at Linear power group, Texas Instruments, Tucson, AZ in 2018 where he worked on power converters, analog-to-digital converters and ultra-low Iq LDOs respectively. From 2012 to 2014 he was a Digital Circuit Designer at Sankalp Semiconductors Pvt. Ltd., India where he worked on standard cell library design for mixed-signal libraries. His current research interests include low-power analog design, supply ripple rejection and power management IC design. He is a peer reviewer for IEEE Access, TCAS-I & II, TPEL, APEC, ISCAS. From 2022-2024 he has been serving as the Chair of San Francisco Bay Area Council PELS Chapter. He is currently serving as the Regional Chair for IEEE PELS Region 4-6 overseeing ~40 chapters. He is also a member of the PELS TC-10 on design methodologies. He is also the webmaster for the MTT-15 technical committee.