A Rail-to-Rail Second Generation Voltage Conveyor for Low-Power Applications

In this paper, a second-generation voltage conveyor (VCII), designed for low-voltage low-power applications, is proposed. A Rail-to-Rail feature is obtained through the use of a bipolar charge pump applied on the voltage supply of the output stage. The circuit has been designed in a 0.18 µm standard CMOS technology operating at a
$\pm\mathbf{0.9}\ \mathbf{V}$
supply voltage, extended by the charge pump to
$\pm\mathbf{1.45}\mathbf{V}$
for the output stage. Spice simulations have shown that the output voltage has a 94
^%
and a 100
^%
dynamic range for a
$\mathbf{10}\ \mathbf{k}\boldsymbol{\Omega}$
and a
$\mathbf{100}\ \mathbf{k}\boldsymbol{\Omega}$
load, respectively. The VCII operates efficiently at relatively low frequencies, within the range of tens of MHz. The average power consumption retrieved from the bipolar voltage sources equals
$\pm\ \mathbf{3.5}\ \boldsymbol{\mu} \mathbf{W}$
, while the same parameter, retrieved at the outputs of the charge pumps, equals
$\pm\ \mathbf{3.5}\ \boldsymbol{\mu} \mathbf{W}$
.