New simple transistor realizations of second‐ generation voltage conveyor

Abstract

Summary In this paper, two new complementary metal oxide semiconductor (CMOS) realizations for second‐generation voltage conveyor (VCII) are presented. The first proposed VCII has a very simple structure employing only six transistors. The second proposed VCII employs 11 transistors, and none of the transistors at both proposed circuits suffer from the body effect. Small‐signal analysis, parasitic elements, and input‐referred noise of the proposed VCIIs are given. Moreover, a new active element called voltage controlled second‐generation voltage conveyor (VC‐VCII) is proposed as dual element of current controlled second‐generation current conveyor (CCCII) active element. Its parasitic resistance at the Y terminal can be controlled electronically. Two presented CMOS structures of VCII are worked as VC‐VCII with slight modification. Proposed circuits are simulated in Cadence Analog environment using TSMC 0.18‐μm process parameters with ±0.9‐V supply voltages. Both CMOS structures occupy a small chip area of 276.8 and 271 μm2, respectively. The bandwidth of the current follower stage of the proposed VCIIs is found as 794 MHz, whereas the bandwidth of the voltage follower stage for the first and second proposed VCIIs is found as 2.57 and 1.92 GHz, respectively. As an application example, voltage‐mode first‐order low‐pass filter has been given with its tunable gain by using VC‐VCII.

0.5 V Current-Mode Low-Pass Filter Based on Voltage Second Generation Current Conveyor for Bio-Sensor Applications

“…A number of VCII structures have been reported recently in literature [11]- [18]. Unfortunately, these structures are designed by rather high supply voltage and high-power consumption such as 1.65 V/330 µW in [11], 0.9 V/120 µW in [12], 1.65 V/320 µW in [13], 0.9 V/664 µW in [16], 0.45 V/79.3 µW in [18]. Therefore, these VCIIs are not suitable for applications to ultra-low power analog signal processing.…”

A New VCII Application: Sinusoidal Oscillators

“…Recently, the dual circuit of CCII, called second-generation voltage conveyor (VCII), has attracted the attention of researchers [35][36][37][38][39][40][41][42][43][44]. In particular, the recent study reported in [35,36] showed that this device helps to benefit from CM signal processing features and overcome the limitations in CCII-based circuits.…”

Towards Realization of a Low-Voltage Class-AB VCII with High Current Drive Capability

“…In [17], a comparison between OA-based circuits and VCII-based circuits was drawn, showing that the problem of the cross-talk effect among inputs in a conventional OA-based non-inverting summing amplifier can be cancelled out using VCII. Literature survey shows the possibility of realizing various VCIIbased analog circuits such as filters, integrators, differentiators, rectifiers, and impedance simulators [16][17][18][19][20][21][22][23][24][25][26][27].…”

“…Literature survey shows that there are very few VCII circuits designed in class AB [25][26][27]30]; however, all of them suffer from poor current drive capability. In [25], a flipped voltage follower (FVF)-based VCII circuit was presented, which can provide an output current up to ±2 mA.…”

“…In the VCII circuit reported in [26], the maximum current at X terminal is limited to ±0.5 mA. The VCII circuit presented in [27] is optimized for the minimum number of transistors. Its current drive capability is limited to ±1.065 mA.…”