DLPA2000: Standby mode

Will,

Can you describe what you are referring to when you mention "Active 1" and "Active 2" modes? If possible, reference the section of documentation that mentions these operating modes for context.

Regards,

Philippe

Hi Philippe,

Please see page 27-28 in DLPA2000 spec or the figure below.

STANDBY: The DMD regulators and LED power (VLED) are turned off, but the IC does respond to the SPI. The device enters STANDBY mode whenever PROJ_ON is set high or DMD_EN(1) bit is set to 0 using the SPI interface after PROJ_ON is already high. The device also enters STANDBY mode when a fault condition is detected(2). (See Protection Circuits).

ACTIVE1:  The DMD supplies are enabled but LED power (VLED) is disabled. PROJ_ON pin must be high, DMD_EN bit must be set to 1, and VLED_EN(3) bit is set to 0.

ACTIVE2: DMD supplies and LED power are enabled. PROJ_ON pin must be high and DMD_EN and VLED_EN bits must both be set to 1.

Will,

Thanks for elaborating. These modes on the DLPA2000 are engaged automatically when appropriate by the DLPC3433 controller. In particular, the DLPA2000 is not designed to be communicated with by anything other than the DLPC3433. 

That being said, it sounds like you are trying to set up power saving functionality on your system. Can you detail your requirements a bit further? There may be an easier way to accomplish what you seek via the DLPC3433 instead.

Regards,

Philippe

Hi Philippe,

The devices that we are working on may be for AR or MR. When a user just listen to music, the user may want to let displays work on a power saving mode. But, it must show warning on the displays immediately when he may be in a danger situation suddenly. Is there a good way for this concept?

BR,

Wilbur.

Wilbur,

There are a couple options you could take to provide such a power saving mode. For starters, I recommend reviewing the DLPC3433 Programmer's Guide: https://www.ti.com/lit/ug/dlpu020d/dlpu020d.pdf

Referencing the above programmer's guide, some commands you can use:

> Using RGB LED Enable (0x52) and RGB LED Current (0x54) you can just illuminator settings to either dim the LEDs or disable them entirely.

> Using Mirror Lock command (0x3A) you can halt the DMD so there is no mirror activity.

> Using Curtain Enable (0x16) you can force the screen output to a black solid field

What kind of power targets are you looking to hit?

Regards,

Philippe

Hi Philippe,

Last year, I designed RGB LED disable for the power saving mode. The power staill costs around 0.5W to keep DLPC3433 working and response immediately. This year, our power team asks for less power if possible. 

As you recommended, I still have some questions. 

1. I can't see the description of Mirror Lock command in the programmer's guide. Could you provide more about it?

2. How much power can we save if I set mirror lock?

3. How much power can we save if I set curtain enable?

4. How much power can we save if I set both of mirror lock and curtain enable?

BR,

Wilbur.

Hi Philippe,

Our power target for the whole device (include XR1 CPU and others) is 50mW with a short response time. 

So far, uOLED for another AR structure can work at standby mode for lower than 15mW per eye. And, the enable time from standby mode is around 150ms.

I checked the power consumption of each eye from the spec while LEDs are all OFF.

DLPA3433 power consumption: 219mW (=1.1*169mA+13*1.8mA+3.3*1mA+3.3*2mA)

DMD power consumption: 162mW (=97.2mW+20mW+15mW+6mW+24mW)

LED power consumption: 0mW (LED off)

DLPA2000: (219mW+162mW)/85%power efficiency =448mW

It's far away from our power target. Please help to assess our requirements.

BR,

Wilbur. 

Wilbur,

thank you for this information. Thank you ahead for your patience. we will look into the power saving options we have available and post back in a few days.

Best Regards,

Arthur

Hi Arthur,

Is there any updated for the power saving?

BR,

Wilbur.

Hello Wilbur, 

The team will get back with an update related to your power saving queries by the end of this week. Thanks in advance for your patience. 

Regards,

Mayank

Wilbur,

Thanks for your patience. I would like to take this discussion offline to help you further. Can you please accept my friend request on E2E and send me a message when you have done the same.

Regards,

Philippe