According to the invention, there is provided a frequency to voltage converter for generating an output voltage proportional to the frequency of input signal. It comprises a switched capacitor circuit for receiving input signal and generating an input current proportional to said frequency, the switched capacitor having a capacitor charging and discharging at said frequency; an operational transconductance amplifier (OTA) for receiving at least one control voltage representative of the input current and generating current proportional to the at least one control voltage; at least one negative feedback circuit connecting input and output of the OTA, each negative feedback circuit comprising: a control transistor coupled to a node of the OTA; a diode connected transistor coupled to the control transistor for sensing current flowing through the control transistor; and a feedback transistor coupled to another node of the OTA, also coupled to the diode connected transistor in a current mirror configuration for mirroring current flowing through the diode connected transistor, and further coupled to a control terminal of the control transistor for varying current through the control transistor till an equivalence is established between the input current and currents through the control, diode-connected and feedback transistors and a voltage at the output of the OTA is proportional to the input current.
Indian patent application no. 1936/MUM/2011
Inventors: Maryam Shojaei Baghini, Jayanta Mukherjee, VINEETH A, SANTHOSH KUMAR G