This paper presents the design of a linear wide output range voltage-to-current (V2I) converter which has a constant transconductance value from a given input voltage. The proposed circuit offers a solution with a low footprint (33 μm x 24 μm) , low power consumption (34 μW) , and a transconductance variation less than 2%. In this paper, the output current is used to generate a pair of symmetrical voltages, equal in magnitude and opposite in sign, to provide the tuning of a body-controlled ring oscillator. The circuit has been designed and fabricated in 28 nm FD-SOI technology from STMicroelectronics.