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A new method of cancelling DC offset in sense amplifier for SFC PUF application

IP.com Disclosure Number: IPCOM000220558D
Publication Date: 2012-Aug-06
Document File: 4 page(s) / 40K

Publishing Venue

The IP.com Prior Art Database

Abstract

A sense amplifier's dc offset can be cancelled effectively by utilizing a combination of servo loop and switched cap circuit

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A new method of cancelling DC offset in sense amplifier for SFC PUF application

A dc sense amplifier of U1 shown in figure1 is an essential element in the application of SFC PUF system, detail of U1 is shown in figure 2. A method of using a differential servo loop to cancel dc offset from the second stage of the amplifier is illustrated in figure 4, which should effectively cancel the offset contributed from both stage 1 and stage 2. Initially the input of U1 is connected to Vcom shown in figure 4 and offset voltage is corrected from Vc2p - Vc2n (auxiliary input), when switches are in operational state indicated from figure 5, the servo loop is open and the correction voltage from the auxiliary input is maintained by the differential switched cap to allow the U1 to read from Vp - Vn (signal input) accurately. At the end of the operational state, a reset state is in place to prepare a next operational state (a total of 16 SFC's (16 NFET pairs) shown in figure 1 mean a 16-operational states).

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