Realization of a 1-V active filter using a linearization technique employing plurality of emitter-coupled pairs

Noise considerations for translinear filters

“…Whereas for MOS transconductors exact linearization is possible, as the square law is a polynomial, exact linearization of a bipolar transconductance is fundamentally impossible, since the exponential function is transcendental. Although the small voltage swings in bipolar -filters have a negative influence on the DR properties, on the other hand, it makes them very suitable for operation at low supply voltages [8], [10], [13]. The DR is, to first order, independent of the supply voltage.…”

“…Transconductance linearization techniques using linear combinations of collector currents are not as effective for bipolar as for MOS transconductors and cannot increase the maximal voltage swings above 100 mV [13]. Whereas for MOS transconductors exact linearization is possible, as the square law is a polynomial, exact linearization of a bipolar transconductance is fundamentally impossible, since the exponential function is transcendental.…”

Low-power MOS integrated filter with transconductors with spoilt current sources

“…4(b)], which requires times as much quiescent current for a given transconductance. The differential pair with a single diffuser described in [4] also has a very similar large signal behavior but a higher current usage, as has the circuit with four scaled differential pairs and maximally flat response described in [5]. It can be shown that all these circuits have a Groenewold noise factor [6], where is the transconductance, between and unity, so there is little difference in the noise behavior.…”

Linear bipolar OTAs employing exponential‐law circuits

“…The parameter values for linearity are obtained by solving equations derived from maximally at approximation [2]. Because the output current of an OTA is expressed as an odd function of v in , all even derivatives of the output current must be zero.…”