1.2 V Sinh‐Domain allpass filter

Abstract

A first-order Sinh-Domain allpass filter topology is introduced in this paper. It is constructed from a class-AB current mirror and appropriately configured non-linear transconductor cells. Due to the inherent class-AB nature of Sinh-Domain filters, the proposed topology offers the capability for handling currents at levels greater than that of the dc bias current level. Also, it offers the well-known features of companding filters such as electronic adjustment of its frequency characteristics and the capability for operation in a low-voltage environment. In addition, a four-phase sinusoidal oscillator design example has been provided. The behaviour of the proposed topology has been evaluated and compared with other already known configurations, where the most important performance factors have been considered.

Electronically Tunable Voltage-Mode Multiphase Sinusoidal Oscillator with Low Output Impedance Nodes Employing VD-DIBAs

“…The multiphase sinusoidal oscillator (MSO) is one important type of oscillator, which is useful for various electronic applications in communication systems, control systems, instruments, power electronics, single-sideband generators [1], etc. The MSO is designed by first-order circuits, such as an all-pass filter [2][3][4][5][6], a high-pass filter [7][8], and a low-pass filter [9][10][11][12][13][14][15][16][17][18][19]. To achieve the same magnitude and phase difference of each output sinusoidal waveform, the MSO should be designed from the same sub-circuit without an additional amplifier.…”

Single transistor RC‐only second‐order allpass filters

“…[9][10][11] Transistor-based first-order RC allpass filters have however been previously reported in Wijenayake et al, 12 as well as first-order sinh domain allpass filters. 13 In Tangsrirat and Pukkalanun, 14 second-order allpass filters were constructed using current differencing transconductance amplifiers (CDTAs), but the number of transistors used is very large. Allpass filters based on such active building blocks are not suitable for high frequency operation.…”

“…This also includes the filters in previous studies . Transistor‐based first‐order RC allpass filters have however been previously reported in Wijenayake et al, as well as first‐order sinh domain allpass filters . In Tangsrirat and Pukkalanun, second‐order allpass filters were constructed using current differencing transconductance amplifiers (CDTAs), but the number of transistors used is very large.…”