MIXED SIGNAL DESIGN DOUBTS

[san2004]

mixed sinal routing

Hello Frends,

Currently I am working on 4 layer motherboard of LCD TV. This board contains high speed digital signals, Audio, video signals, Tuner ( RF) signals. Since the board size is very small at some places I have to route digital signals like HDMI ( Main controller to HDMI Receiver IC) below regulator section. Regulator is on the bottom side & big copper patch is also provided for all i/p & o/p current flows. HDMI Routing is on the Top side.Inner two layers are Power & Gnd planes. Will heating of regulator affect the HDMI signals ? Since I cannnot change the placement is there any other solution ? Pls help.

Also can I convert in anyway Cadence Allegro file ( .brd) to PADS (.pcb ) File ?

Pls let me know if anyone from Mumbai, India knows Cadence Allegro. I need urgent help.

Thanks in advance.... Kindly waiting for the replies !!
Byeee

 

[Johnson]

Is regulator linear or switching? Noise is much more concern than heat I believe,

Converting BRD to PCB is not possible directly, you may need third party tools like Altium Designer.

 

[san2004]

Hi,

Thanks for the reply.

It is switching regulator ..i think switching regulators generate more noise than liner regulators (??),If we add GND shielding & copper pours with mutiple vias will this help to reduce the noise ?

Bye..

 

[Johnson]

Yes, switching regulator operation is based on turning on/off a power supply on inductor and filter which means large amount of noise. Filtering and good baypassing is crucial, also take care of placement, separated plane also helps.