LM3409HV: Please check my design about LM3409HV application

MinKyu Kim

Part Number: LM3409HV

Hello,

Please check my design about LM3409HV?

The application is Heliport LED Driver.

LED module consist 5 series and 5 parallel. Each LED Vf is 3V and I want to driver it 350mA to 1A. (CREE/ XPGDWT-U1-0000-00E5E)

(But It will used 350~500mA.)

I'll control output current using potentiometer(VR1).

I thought it regulate reference voltage where input IADJ pin.

https://drive.google.com/drive/folders/1ZlMItlmvhQ5N00PlqSImHqpkfzCbhRsk?usp=sharing

So I set factors like attached files and calculate other values like resistor, capacitor etc.

I linked my google drive what uploaded schematic and calculate papers.

Please check wrong point and feedback to me.

Best regards,

over 2 years ago

0 Xiaoguang over 2 years ago

TI__Genius 17640 points

Can you just attach the file? The link doesn't work for me.

0 MinKyu Kim over 2 years ago in reply to Xiaoguang

Prodigy 100 points

I didn't know how to attach files.

It just drag and drop. lol

Anyway, I attached files.

please check it works.

Thanks

6064.LM3409HV.pdf LM3409HV Factors.pdf

+1 Xiaoguang over 2 years ago in reply to MinKyu Kim

TI__Genius 17640 points

Q2 is PFET, Drain needs to connect to switching node and Source connect to CSN.

IL-MAX is calculated up to 5.25A, SRR6028-7R3Y is 2.2A inductor as I checked on website, please double check, the saturate current should be higher than IL-MAX over operation range with some margin (like 20% margin)

What is R71 & R78 size and power rating? As current is over 5A, power dissipation needed to be considered.

Also, R78 = 3K should be wrong. Power loss on the resistor will be as high as 75KW

0 MinKyu Kim over 2 years ago in reply to Xiaoguang

Prodigy 100 points

Thank you.
I'll Change Inductor, the saturate current is higher than IL-MAX value.
And I missed change resistor size.

R71 will be changed power resistor like DIP type.
and R78 is shunt resistor and it's value have to change by current sensing IC (INA190A3IDCKR) I guess it's tens of mΩ

Is there anything else I need to check?

Best regards,

0 Xiaoguang over 2 years ago in reply to MinKyu Kim

TI__Genius 17640 points

Others should be ok.

Power management

Power management forum

LM3409HV: Please check my design about LM3409HV application