DS90UB941AS-Q1: Max power consumption

Hi Harry,

Quick clarification for the specification that is in the datasheet -

Harry Shin1 said:

BTW, our datasheet max condition is single DSI(210MHz) and dual FPD output 3.675Gbps each.

f_{DSI_CLK} is measured at 630 MHz for this test, and the FPD-Link PCLK is measured at 210 MHz over the dual link.

Harry Shin1 said:

The use case they looking into is 2 DSI input and 2 FPD output and both DSI PCLK is 105MHz each

Is the understanding correct with 2 DSI inputs with a specific data rate (105 MHz / 210 Mbps?) and the FPD-Link PCLK is at 210 MHZ?

Please see this reference for our similar 98x DSI device:

Comparatively, the specification for total power consumption between x1 DSI input and x2 DSI inputs is around 122 mW, so while this depends on clocking rates that are used (higher frequencies use more energy), the max total power consumption ~920 mW, do you have the specific rates used for DSI and FPD-Link for this system?

Thanks,

Miguel

Hello Miguel,

Yes this is what I need.

BTW, can I know current of 1.2V and 1.8V and VDDIO each? Because Power design needs to be calculated by current level based. Would you pls help answer this to customer as well?

Thank you.

Hi Harry,

Do you need the currents of both scenarios for 1.8V and 3.3V applied to VDDIO?

Maximum currents for the V1.1 and V1.8 rails are supplied here:

This should apply for VDDIO = 3.3V, but it sounds like a second circuit would be designed for VDDIO = 1.8V?

Please let me know, thanks.

Miguel

Hello Miguel,

You've informed 1.106W is max power consumption for 2DSI input case with independent mode.

But datasheet shows different use case as below. It only consumes 681.45mW. 

Would you pls help check max current of each power(VDDIO=1.8V case) for 2DSI independent mode worst case??

Thank you.

Hi Harry -

Harry Shin1 said:

You've informed 1.106W is max power consumption for 2DSI input case with independent mode.

Miguel Bolante said:

Please see this reference for our similar 98x DSI device:

The figure I shared was specifically for a different device. I compared the power consumption between 1 DSI input and 2 DSI input to show the difference was around ~120 mW. Not the same data sheet.

Miguel Bolante said:

Comparatively, the specification for total power consumption between x1 DSI input and x2 DSI inputs is around 122 mW, so while this depends on clocking rates that are used (higher frequencies use more energy), the max total power consumption ~920 mW, do you have the specific rates used for DSI and FPD-Link for this system?

Please refer to this statement above, this information will be helpful in understanding the needs of the system for power consumption. Notice the estimate for max total power consumption is ~920 mW using the reference.

Harry Shin1 said:

But datasheet shows different use case as below. It only consumes 681.45mW. 

Was this measured on the actual system? The values that are shared are MAX values, not typical - so you may see lower consumption if taking physical measurements.

Best,

Miguel

Hello Miguel,

Thanks for the answer.

Here is condition which need your help.

With this condition, What is max current of VDD11, VDD18 each? Could you pls help answer this? If you want, I will move to private E2E.

Thank you.

Thanks Harry,

I will check the internal database to see if these conditions have already been tested with this device. I'll provide updated feedback here within the next business day.

Best,

Miguel

Hello Miguel,

Would you pls help answer this?

Thank you.

Hi Harry,

I've looked through the previous archives regarding maximum power consumption conditions for the 941AS device, this is the only test condition that is listed in documentation. This specific test condition is not tested - but there is the previous answer with VDDIO 3.3V reference:

Miguel Bolante said:

Notice the estimate for max total power consumption is ~920 mW using the reference.

Is the customer trying to optimize this value by finding the lowest maximum power as reference?

Best,

Miguel

Hello Miguel,

Many thanks for your support.

Yes, Customer will choose PMIC current rate as 941AS max power consumption.

Thank you.