Low-Power Audio/Video Switch for Dual SCART Connectors

The MAX9598 dual SCART matrix routes audio and video signals between a set-top box decoder chip and two external SCART connectors under I²C control. Operating from a 3.3V supply and a 12V supply, the MAX9598 consumes 70mW during quiescent operation and 471mW during average operation when driving typical signals into typical loads. Video input detection, video load detection, and a 1.7mW low-power mode facilitate the design of low-power set-top boxes.

The MAX9598 audio section contains a buffered cross-point to route audio inputs to audio outputs. The DirectDrive® output amplifiers create a 2VRMS full-scale audio signal biased around ground, eliminating the need for bulky output capacitors and reducing click-and-pop noise. The zero-cross detection circuitry also further reduces clicks and pops by enabling audio sources to switch only during a zero-crossing.

The MAX9598 video section contains a buffered cross-point to route video inputs to video outputs. The standard-definition video signals from the set-top box decoder chip are lowpass filtered to remove out-of-bandwidth artifacts.

The MAX9598 also supports slow-switching and fast-switching signals. An interrupt signal from the MAX9598 informs the microcontroller (µC) when the system status has changed.

The MAX9598 is available in a compact 40-pin thin QFN package and is specified over the 0°C to +70°C commercial temperature range.

Applications

* DVD Players * Set-Top Boxes * TVs

* 70mW Quiescent Power Consumption

* 1.7mW Low-Power Mode Consumption

* 0.1mW Shutdown Consumption

* Clickless/Popless, DirectDrive Audio

* Video Input Detection

* Video Load Detection

* Video Reconstruction Filter with 10MHz Passband and 52dB Attenuation at 27MHz

* 3.3V and 12V Supply Voltages