SN75DP139: Transition time by OE_N and DDC_EN

We are trying to figure out the transition times that you are asking for. In what application do you need these parameters? Are these parameters critical to your application?

Hi

 

Thank you for your reply and support.

Application is DVI-I (Digital and Analog) I/F on PC platform.

 

DDC_EN:

I would like to control the DDC buffer by HPD.

When HPD= high (DVI monitor is connected), DDC buffer is enabled

When HPD= low (DVI monitor is not connected) , DDC buffer is disabled

 

OE_N:

I would like to control Main Link activity by HPD to reduce power consumption during DVI monitor is not connected.

When HPD= high (DVI monitor is connected), normal mode.

When HPD= low (DVI monitor is not connected), power saving  mode.

 

Best Regards,

Chiba.

 

 

You will have to invert the HPD for OE_N if you want the device to be in normal mode when HPD is high and in power savings mode when HPD is low.

We do not know the transition times that you requested. the transition time might be short enough depending on how long the Denounce is on HPD and how long after HPD goes high the host starts sending information. 

Hi

Thank you for your reply and support.

>You will have to invert the HPD for OE_N if you want the device to be in normal mode when HPD is high and in power savings mode when HPD is low.

I understood.

>We do not know the transition times that you requested. the transition time might be short enough depending on how long the Denounce is on HPD and how long after HPD goes high the host starts sending information.

Please see following figures. Here is my question. I would like to know td1, td2, td3 and td4.

Timing.pdf

Best Regards,

Chiba.