LP8868X-Q1: Inquiry Regarding LP8868-X Boost Topology for 46W LED Load

Rabina Khandei

Part Number: LP8868X-Q1

Tool/software:

Dear Sir,

I hope you're doing well.

I would like to confirm whether the LP8868-X, configured in boost topology, is capable of handling a load of 46 watts consisting of 12 LEDs, each with a forward voltage of 3.2V. I have attached the document here.

Based on the datasheet, I understand that the LP8868-X supports boost operation with an input voltage range of 4.5V to 65V and can deliver up to 4A output current. However, I would appreciate your guidance on whether this configuration is suitable for the specified LED setup, especially in terms of power handling.

Looking forward to your expert advice.

Best regards,

Rabina

LP8868.docx

25 days ago

0 Gui He 25 days ago

TI__Mastermind 27276 points

Hi Rabin

Our expert will reply to you later.

Thanks and best regards.

0 Suchen Dong 25 days ago

TI__Expert 3211 points

Hi Rabina,

An single LP8868X-Q1 can not support that power range with boost topology. 4A is for buck topology. You could choose multiple LP8868XQ1 instead.

The power capability is highly related to the input voltage range. Could you please provide more information?

Best regards,

Suchen

0 Rabina Khandei 22 days ago in reply to Suchen Dong

Prodigy 10 points

Hello Sir,

The input voltage range is between 6V-19V.

0 Rabina Khandei 22 days ago in reply to Rabina Khandei

Prodigy 10 points

I want to know wat is the maximum power rating of LP8868X-Q1(boost topology)?

0 Suchen Dong 22 days ago in reply to Rabina Khandei

TI__Expert 3211 points

Hi Rabina,

For 6V input, the power loss is high due to the high input current. Hence the power capability is limited.

You could use this calculation tool for evaluation. To be noted, the result is just for a reference.3821.LP8868XY_encrypted.xlsx

Best regards,

Suchen

0 Rabina Khandei 22 days ago in reply to Suchen Dong

Prodigy 10 points

Hello Sir,

Our input voltage ranges from 6.4V to 19V with a current of 1.2A. We will be managing the power loss within this range.
Could you please confirm if we can maintain a count of 12 LEDs in LP8868X-Q1 (boost topology) under these conditions?I’ve attached the document outlining our requirements for your reference.

Looking forward to your feedback.

With regards,

Rabina

3286.LP8868.docx

+1 Suchen Dong 22 days ago in reply to Rabina Khandei

TI__Expert 3211 points

Hi Rabina,

Just as I said, one LP8868-Q1 cannot handle that power range, especially for 6V input. How much temperature rise can you accept? You could use the calculation tool to get the estimated temperature rise.

Best regard,

Suchen

0 Rabina Khandei 21 days ago in reply to Suchen Dong

Prodigy 10 points

Hi Sir,

can expect 70+-5 degree Celsius

thank you

0 Rabina Khandei 21 days ago in reply to Rabina Khandei

Prodigy 10 points

sir , i want the answer of this question ?

0 Rabina Khandei 21 days ago in reply to Rabina Khandei

Prodigy 10 points

wat is the max power it can handle ?

+1 Suchen Dong 21 days ago in reply to Rabina Khandei

TI__Expert 3211 points

Hi Rabina,

You could use the thermal foldback function of LP8868X-Q1. When the junction temperature exceeds the threshold, the current will automatically decrease.

An estimated max current at different input voltage based on your system will be:

6V Iout = 400mA

9V: Iout = 650mA

12V: Iout = 900mA

Hence, I will suggest an 800mA output current, with 50% derated current (400mA) in low input voltage (6V).

Best regards,

Suchen

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LP8868X-Q1: Inquiry Regarding LP8868-X Boost Topology for 46W LED Load