Frequency to dc converter

Claim 1

A frequency to DC converter for energizing a utilization means with a signal proportional to the frequency of an input signal comprising: a. means for producing a reference voltage at first and second terminal thereof; b. output circuit means for producing an output voltage in response to an average current therethrough; c. a pair of series connected capacitors in series with said output circuit means, said reference voltage means energizing said series connected capacitors with a substantially constant voltage; d. complementary field effect transistors individually shunting each of said capacitors alternately to shunt and discharge one of said capacitors while permitting the other capacitor to be charged by said reference voltage means; e. a switching transistor in a common emitter configuration adapted for energization by the input signal, the gate electrodes of said field effect transistors being coupled to the collector of said switching transistor; f. said field effect transistors having substrate electrodes, one of said field effect transistor substrate electrodes being connected to first said reference voltage terminal and the other of said field effect transistor substrate electrodes being connected to said second reference voltage terminal.