An AC-coupled output includes a series capacitor, while a DC-coupled output does not. This article explains the reasons for choosing either an AC-coupled or a DC-coupled video output. Maxim's DirectDrive video technology eliminates large output coupling capacitors and sets the output video black level near ground, which has the characteristics of an AC-coupled connection but the simplicity of a DC-coupled connection, is introduced. The working principle of Capacitive Charge Pump, is introduced too. Take the case of MAX9532 analyses the main choice of the components and parts in peripheral circuit, it has listed the precautions in the circuit design.