ISL4089

The ISL4089 is complete DC-restored monolithic video amplifier sub-system. It contains a high performance video amplifier and a nulling, sample-and-hold amplifier designed to establish a programmable DC output level.

When the HOLD logic input "0" is applied the DC restore function is active. The sample-and-hold amplifier loop is closed and used to null the DC offset of the video amplifier. This can occur during sync, or, at any time that a black level is expected. When the HOLD input "1" is applied, the correcting voltage is stored on the video amplifier's input coupling capacitor. This condition must be true during active video. The restored DC voltage level can be adjusted using an external reference voltage applied to the VREF pin.The device operates from a single +5V supply and is ideal for +5V only systems when used with a sync separator, such as the EL1883.

The ISL4089 is intended to directly replace the EL4089 only in certain applications. This direct replacement requires that the single positive supply is no higher than +5.5V and that no part of the clamped output goes below ground. The NC on pin 6 is not internally connected, so it can be connected to the -5V pin in existing EL4089 applications.

The ISL4089 is specified for operation over -40°C to +85°C temperature range.