DLP4500: Connect trigger out from two projectors

Xinran Liu

Part Number: DLP4500
Other Parts Discussed in Thread: DLPC350

Hello,

I was wondering if it's safe to connect two trigger out wires from two different DLP4500 projectors together? Is the any protection against backfeed from another trigger source. I was trying to use two projectors to trigger one camera.

Thanks!

over 4 years ago

0 Philippe Dollo over 4 years ago

TI__Mastermind 28005 points

Xinran,

Welcome to the E2E forums and thanks for your interest in our DLP technology.

You may want to start by reviewing the DLPC350 controller datasheet (controller for the DLP4500 chipset). https://www.ti.com/lit/ds/symlink/dlpc350.pdf

Per the DLPC350 datasheet, both of the trigger out pins on this controller are bidirectional. If you want to use multiple trigger outputs going to a single camera, you may want to buffer these outputs to ensure reliable operation.

I hope this helps.

Regards,

Philippe Dollo

0 Xinran Liu over 4 years ago in reply to Philippe Dollo

Prodigy 50 points

Hello Philippe,

Thanks for your help! I read the DLP350 datasheet. In section 6.1 Absolute Maximum Ratings (page 13), it says the Input Voltage limit applies to external input and bidirectional buffers. I think TRIG_OUT_1 or TRIG_OUT_2 are both 3.3-V LVCMOS I/O buffer, with 8-mA drive (Type B2).

Thus I think it's okay if a 3.3V voltage is applied to the trigger out pin (I was worried about damage to the chip).

Please correct me if I'm wrong. I will consider to buffer outputs for reliable operation.

Thanks,

Xinran

0 Vivek Thakur over 4 years ago in reply to Xinran Liu

TI__Mastermind 23090 points

Hello Xinran,

That should be fine.

regards,

Vivek

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DLP4500: Connect trigger out from two projectors