POWER SUPPLY RIPPLE REJECTION IN TUNER OSCILLATOR STAGE

摘要

A bipolar transistor (Tr) in an oscillator stage of a tuner is provided with a diode (D 10 ) in series with a resistor (R 11 ) coupled between the base of the transistor (Tr) and the reference voltage to which the emitter of the transistor (Tr) is coupled. The diode (D 10 ) allows a decreased resistor (R 11 ) value which causes the supply voltage ripple (Vr 1 ) on the collector originating from the base to decrease so as to better compensate the supply ripple (Vr 2 ) on the collector directly originating from the supply voltage (Vs.).