Abstract: A wide range voltage controlled oscillator including a voltage-to-current conversion unit generating a control current responsive to a control voltage, and an offset current generation unit generating an offset current. The offset current generation unit is responsive to the control voltage and, at certain times, is responsive to a reference voltage. An adding unit adds the control current to the offset current, and generates an oscillation control current. An oscillation unit generates the oscillation signal responsive to the oscillation control current.

Abstract: An automatic gain control circuit includes a first amplifier for receiving a video signal to produce a first signal with a gain varied in response to a control signal, a low-pass filter for removing a color component from the first signals to produce a second signal, a sync separator for separating synchronizing pulses from the second signal to produce a third signal, a delay circuit for delaying the third signal for a given time to produce a fourth signal, a clamper for clamping the second signal upon a constant reference voltage generated from a constant voltage generator 26, a sample and hold circuit 26 for receiving the fourth signal and a fifth signal to produce a sixth signal maintaining for a given time a level of a back porch of the fifth signal, a transconductance amplifier for comparing the sixth signal with a constant reference voltage to produce a difference signal as a seventh signal, a capacitor for integrating the seventh signals to produce a direct current error voltage as an eighth signal, an