Comments on "A novel wide-band differential amplifier"

The circuit proposed by Khan and Arun Kumar in ibid, vol. 41, p.555-559 (Aug. 1992) has been originally proposed by Soliman and Ismail (see IEEE Trans. Circuits Syst., vol.CAS-26, p.112-117, 1979), who have derived the condition for minimum phase error, taking into account the single-pole model of the OA. The effect of second pole on this actively compensated finite gain amplifier has been analyzed by the author (see AEU, vol.42, p.192-194, 1988), wherein this circuit has been completely compared with other state of the art realizations regarding (a) gain error, b) phase error, (c) conditions required for minimizing phase error and gain error, (d) matching of active devices whether required, and (e) condition for stability taking into account the second pole of the opamp.<
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