tps2388: How to through the serial transmission scheme to point the light on the POE

dave lan

Part Number: TPS2388

hi sir,

Now customers have open case for 16 POE switches and customers to use the scheme is TPS2388, but now customers encounter a problem, is the customer want to by a serial of solutions to some 16 POE indicator (customer class is given priority to, vice board minutes, switch on the motherboard, PSE chip in vice class, customer want to use a serial of two wires to the motherboard, motherboard in resolution to it a little 16 lamp, if is parallel transmission, so the Lord will have too much seat between vice board feet, area for very big).

over 6 years ago

0 Thomas Amlee over 6 years ago

TI__Genius 9230 points

Hi Dave,

I have notified our PSE experts.

Thanks,
Thomas A.

0 Jack CCY over 6 years ago

TI__Intellectual 1695 points

Hi Dave,

You want the LED light to indicate the port voltage? right?
There are two main methods:
1. Use TVS and LED light paralleled with port like TPS2388EVM, the link is as below, you can refer to page22
www.ti.com/.../sluubq7a.pdf

2. Use MCU GPIO to control the LED light.
MCU can read the power good status from PSE and use IO port to control LED light.

Thank you so much.
Best Regards
Jack Chen

0 dave lan over 6 years ago in reply to Jack CCY

Intellectual 520 points

hi Jack,

Now customers want to do this project with MCU, because now is 16 mouth switches, require parallel light, such links to seat more class (motherboard (MCU) and deputy (PSE) are separated), we have a serial program,

0 Jack CCY over 6 years ago in reply to dave lan

TI__Intellectual 1695 points

Hi Dave,

Would you please specify the question? I'm not sure what you mean.
Thank you so much.

Best Regards
Jack

0 dave lan over 6 years ago in reply to Jack CCY

Intellectual 520 points

HI Jack,

Now the customer wants to use the form of software to Control LED lighting, and the customer wants to communicate with MCU through serial data, and control the light by shifting,Do you have any information on this?

thanks!

Dave

0 Jack CCY over 6 years ago in reply to dave lan

TI__Intellectual 1695 points

Hi Dave,

MCU can be used to control the LED and TPS2388, the communication between TPS2388 and MCU is based on I2C. So if you would like to learn the how MCU controls the TPS2388, you can check the reference code online.

www.ti.com/.../toolssoftware

0 dave lan over 6 years ago in reply to Jack CCY

Intellectual 520 points

Hi Jack，

I would like to ask if the code you give includes MCU to read TPS2388 port status and control the LED lighting program?

0 Jack CCY over 6 years ago in reply to dave lan

TI__Intellectual 1695 points

Hi Dave,

It includes MCU reading TPS2388 port, but it doesn't control the LED lighting. Because we use the port voltage to control the LED on the port.
You can easily use IO port to control the LED in your program, adding some code.

Thank you so much.
Best Regards
Jack Chen

0 dave lan over 6 years ago in reply to Jack CCY

Intellectual 520 points

Hi Jack，

Ok, I see. I have another question. If I do this with the hardware, what does the TVS tube do? Can I replace it with a resistor，Please help. Thank you~

0 Jack CCY over 6 years ago in reply to dave lan

TI__Intellectual 1695 points

Hi Dave,

TVS is used to control the voltage level of LED turning on. We would like to indicate the port voltage is 48V and then the LED turns on.

So we use a 22V TVS and when the port voltage is high enough the TVS will turn on and the LED will turn on.

Also this will help to reduce the LED voltage. If you use a resistor, the LED may turn on when there is a small port voltage.

Thank you.

Best Regards

Jack Chen

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tps2388: How to through the serial transmission scheme to point the light on the POE