In this paper, a highly linear transconductance cell with widely tunable control voltage is proposed based on bulk-driven technique. The transconductance is configured using a self-biased structure to achieve a high linear operation under the control voltage variations. In addition, the transistors of the input differential pair are driven from the bulk terminal to increase the input dynamic range and provide a low-voltage structure. In order to control the DC currents through transistors and balance the operation of the circuit under unwanted changes such as corner cases, a reference voltage is improvised. The proposed cell is simulated using a 180-nm CMOS technology under a supply of 0.5 V. Simulations results show that the DC gain changes from 0 dB to 14.2 dB for control voltage variations in the range of 0 V-0.5 V. As well, the common mode input voltage is able to change from 0.125 V to 0.375 V without degeneration in linearity, which results in a 0.25 V input dynamic range. The proposed cell consumes only 250 nW power, suitable for ultra-low-power applications.
