Video amplifier for combining luminance and chrominance signals

In a color television receiver, a video amplifier circuit for combining chrominance and luminance signal components and for supplying resultant color representative signals to an image reproducing device comprising:

• means, having at least first and second terminals, for providing a direct operating voltage;
• chrominance signal amplifying means comprising at least one amplifier section including a load circuit, first and second semiconductor devices of a first conductivity type, each having a control electrode and a main current conduction path associated with said control electrode, said conduction paths of said first and second devices and said load circuit being direct current coupled in series relation to said first terminal, and means for coupling a source of direct bias voltage less than said operating voltage to said control electrode of said second device;
• luminance signal amplifying means comprising a third semiconductor device of a second conductivity type arranged in a voltage follower configuration and having a main current conduction path direct current coupled to said second terminal and a control electrode associated with said path;
• a source of chrominance signals;
• a source of luminance signals;
• means for direct current coupling said chrominance signals to said control electrode of said first device such that said first and second devices operate as a cascode amplifier for said chrominance signals;
• means for direct current coupling said luminance signals to said control electrode of said third device;
• means for direct current coupling said main current conduction paths of said first, second and third devices in series relation with said load circuit between said first and second terminals such that a combination of chrominance signals, luminance signals and associated direct current components is produced in said main current paths of said first and second devices;
• and
• means for direct current coupling output signals from said load circuit to said image reproducing device, whereby amplified color representative signals including direct current components are provided to said image reproducing device.