DLPC3479: Signal specification of TRIG_IN of DLPC3479

Nobuyoshi Arai44

Expert 2575 points

Part Number: DLPC3479
Other Parts Discussed in Thread: DLP4710EVM-LC

Hello TI team,

I have got a question about the specification of Trigger In signal (N6) of DLPC3479.

Would you please answer the question?

First, is Trigger In signal treated by an edge or a pulse?

If it is triggered by a pulse, we would like to know the minimum and maximum duration of pulse is needed.

If it is an edge, please show us the slew rate and threshold voltage.

Thank you for your information.

Nobu Arai

over 3 years ago

0 Vivek Thakur over 3 years ago

TI__Mastermind 22830 points

Hello Arai-san,

How are you? The DLPC3479 datasheet has request information:

https://www.ti.com/lit/ds/symlink/dlpc3479.pdf

1. Trigger 1 out - is configured active high polarity and will have a minimum pulse width of 20 microseconds.

2. Trigger 2 out is configured active high polarity and stays active during the pattern

Both pins are defined as "1.8-V LVCMOS I/O buffer with 8-mA drive"

Hope this answers your questions.

regards,

Vivek

0 Nobuyoshi Arai44 over 3 years ago in reply to Vivek Thakur

Expert 2575 points

Hello Vivek-san,

Thank you for the answer. It is good to hear from you.

However, we would like to know about the specification of Trigger In signal.
Our customer is considering to design the FPGA circuit to connect to the DLPC3479 and they want to know what signal they need to input to the TRIG_IN of DLPC3479 so that it can be recognized as an active.

Thank you for your help.

Nobu Arai

0 Mayank Khandelwal over 3 years ago in reply to Nobuyoshi Arai44

TI__Genius 9971 points

Hi Nobu-san,

The specification details of the trigger-in signals are as follows -

1. Trigger In signal is detected by its edge.

2. The information related to the threshold voltages can be found out in section 6.6 of the DLPC3479 datasheet.

If you look at the schematic of DLP4710EVM-LC, you will find that 3DR pin which is reserved for Trigger In is based on P3P3V_INTF. Hence the threshold values corresponding to 3.3 V would be applicable here.

3. In regards to the slew rate (rise time, fall time), kindly refer to section 10.6 of the DLPC3479 datasheet.

Regards,

Mayank

0 Nobuyoshi Arai44 over 3 years ago in reply to Mayank Khandelwal

Expert 2575 points

Mayank-san,

Thank you for the answer.

I understood that the TRIG_IN signal specification and answered to the customer.

If we get any additional request, I will let you know.

Best Regards,

Nobu Arai

0 Mayank Khandelwal over 3 years ago in reply to Nobuyoshi Arai44

TI__Genius 9971 points

Nobu-san,

Thanks for the confirmation Yes, please reach out to me if you have any additional queries.

Regards,

Mayank

0 Nobuyoshi Arai44 over 3 years ago in reply to Mayank Khandelwal

Expert 2575 points

Hello Mayank-san,

I have got an additional question from the customer.

They want to know how often the DLPC3479 is sampling TRIG_IN signal.

In other words, if you have any information what MHz the DLPC3479 is sampling the TRIG_IN signal, it would be helpful.

Thank you very much for your help.

Nobu Arai

0 Philippe Dollo over 3 years ago in reply to Nobuyoshi Arai44

TI__Mastermind 28005 points

Nobu-san,

Let us investigate further and help you with this further inquiry. Thanks for your patience.

Regards,

Philippe Dollo

0 Nobuyoshi Arai44 over 3 years ago in reply to Philippe Dollo

Expert 2575 points

Hello Philippe-san,

Thank you for your investigation.

This is the question from our customer and they want to know the status of this inquiry.

So, if you have any update, it would be helpful.

Thank you for your suppoting.

Nobu Arai

0 Austin Snyder over 3 years ago in reply to Nobuyoshi Arai44

TI__Genius 12575 points

Nobu-san,

Thank you for your patience as we are still looking into this information for you.

Regards,

Austin

0 Austin Snyder over 3 years ago in reply to Nobuyoshi Arai44

TI__Genius 12575 points

Nobu-san,

The Trigger-In signal is not necessarily tied to a sampling frequency. Rather, the signal triggers a hardware interrupt when a rising edge is detected on the Trigger_In pin.

Please let us know if you have any further questions.

Regards,

Austin

0 Nobuyoshi Arai44 over 3 years ago in reply to Austin Snyder

Expert 2575 points

Hello Austin-san,

Thank you for the answer. I understand that TRIG_IN signal is not related with a sampling frequency.

I answered it to the customer and if we get additional question, we will let you know.

Best Regards,

Nobu Arai

0 Mayank Khandelwal over 3 years ago in reply to Nobuyoshi Arai44

TI__Genius 9971 points

Nobu-san,

Thanks for the confirmation.

I would also like to add a couple of points -

The frequency of Trigger In pulses should be less than or equal to 1/ (summation of exposure times configured for the internal pattern display.) in order to achieve correct pattern display.

The user should also ensure than the trigger in pulses are given only when the pattern ready signal is active or else the pulses will be ignored by the controller.

Please let me know if you have any other queries.

Regards,

Mayank

0 Nobuyoshi Arai44 over 3 years ago in reply to Mayank Khandelwal

Expert 2575 points

Hello Mayank-san,

Thank you for your additional answer, I will add your comments to the answer for the customer.

If we get any additional request, I will let you know.

Best Regards,

Nobu Arai

0 Vivek Thakur over 3 years ago in reply to Nobuyoshi Arai44

TI__Mastermind 22830 points

Nobu-san,

You are always welcome :)

Vivek

DLP®︎ products

DLP products forum

DLPC3479: Signal specification of TRIG_IN of DLPC3479