Home

Dr. Subhajit Sen

Subhajit Sen

Associate Professor,

Contact: Room 212-A, IIIT-B,Electronic City, Bangalore

E-mail: subhajit_sen@iiitb.ac.in, Phone: 91-80-4140-7777 (Extension 161)

I work (and teach) in the area of analog and mixed-signal interface and power management circuits using both microelectronic(VLSI) IC, nanoelectronic and COTS technologies. Why analog? The physical world is observable (and controllable) only as analog signals: be they weak signals at the input of wireless receivers or the high-power outputs of motor-controllers. Even digital logic signals transmitted in any band-limited medium have to be treated as analog signals before they can be recovered without error as is done in circuits called SERDES(serializer-deserializer). Furthermore, it has been well established that the neurons in the human brain process information in analog form (that can be mimicked by transistors) with orders of magnitude higher efficiency in power as compared to digital computer circuit based algorithms: a computing paradigm known as neuromorphic processing. Therefore the fundamental importance of analog signal processing will never go away.

However, a curious and perhaps surprising reality for a practitioner of the analog art is as follows: because of the ubiquity of digital communication and signal processing, it is not enough to know how to process and signal-condition raw analog signals i.e. know how to amplify, filter, mix up or down, add/subtract analog signals. One must also be able to present the signal in digital format to a computer and conversely convert it back to the analog domain without losing signal-to-noise ratio. The latter is accomplished using data-converters (A/D and D/A) and phase-locked-loops that are an important component of modern analog and RF circuit research.

The field of CMOS VLSI analog & RF integrated circuits has been made possible by the pioneering work of Profs. Paul Gray and Robert Meyer and many of their students at UC Berkeley as well as in companies in Silicon Valley and elsewhere(Canada and Europe). Much of modern embedded electronics would not have been possible without their key contributions. Other pioneers in low-power VLSI are Prof. Eric Vittoz(ETH) and Carver Mead(Caltech). Important recent contributions have come from Profs. Behzad Razavi.