LM61495-Q1: 15V/10A

Hirokazu Takahashi

Part Number: LM61495-Q1
Other Parts Discussed in Thread: LM61440-Q1, LM61460-Q1, , LM61460, LM61495, LM61440, LM25141

Hello support team

We are studying below power lines.
Vin : 22~30V
Vout : 19V/4A, 12V/6A, 15V/10A

We could find below products at TI.com as the possibility product for above requirements.
1) 19V/4A : LM61440-Q1
2) 12V/6A : LM61460-Q1
3) 15V/10A : LM61495-Q1

And then, my question is below.
Q1. Do you think my selection products will be acceptable for each power lines? If you have other recommended products, please let me know.
Q2. I guess that LM61495-Q1 will be able to cover all conditions. Is it better way to use different products for each power lines than LM61495-Q1 at all power lines at total efficiency point of view?
Q3. How much heat radiation area is required when using LMH61495-Q1 at 15V / 10A?
Q4. Do you have other options or recommended products for reducing the mount area on PCB?

Best Regards,
Hirokazu Takahashi

over 5 years ago

0 Andy Chen over 5 years ago

TI__Mastermind 33875 points

Hi Hirokazu,

Can you provide more information for estimation:

1. Max ambient temp

2. PCB size and layers?

3. Prefer switching freq?

4. the load current is transient peak? or nominal value?

B R

Andy

0 Andy Chen over 5 years ago

TI__Mastermind 33875 points

Hi Hirokazu,

I will close this thread if you have no more inquiry.

B R

Andy

0 Hirokazu Takahashi over 5 years ago in reply to Andy Chen

TI__Expert 8420 points

Hello Andy-san

I'll put my answer for your question below.

1. Max ambient temp
-> Ta=40C
2. PCB size and layers?
-> It hasn't been fixed yet. We want to investigate PCB size to achive 3 kind of power lines. We plan to use 4 layers PCB.
3. Prefer switching freq?
-> It hasn't been fixed yet. Could you suggest better solution at points of view with thermal, PCB size and FET switching loss?
4. the load current is transient peak? or nominal value?
-> It is transient peak.

Best Regards,
Hirokazu Takahashi

0 Andy Chen over 5 years ago in reply to Hirokazu Takahashi

TI__Mastermind 33875 points

Hi Hirokazu

For LM61460, you can simulate the application in Webench with Fsw=400KHz to check the thermal performance.

For LM61495, I will check it's possible load current for 15V out.

B R

Andy

0 Hirokazu Takahashi over 5 years ago in reply to Andy Chen

TI__Expert 8420 points

Hello Andy-san

Could you please reply your answer for my each questions on my first post?

Best Regards,
Hirokazu Takahashi

0 Andy Chen over 5 years ago in reply to Hirokazu Takahashi

TI__Mastermind 33875 points

Hi Hirokazu:

See my reply below

Q1. Do you think my selection products will be acceptable for each power lines? If you have other recommended products, please let me know.

LM61440/460 is better for 4 A and 6A rail, we need to check if LM61495 can handle 15V/10A output.

Q2. I guess that LM61495-Q1 will be able to cover all conditions. Is it better way to use different products for each power lines than LM61495-Q1 at all power lines at total efficiency point of view?

LM61440/460 is better for 4 A and 6A rail, LM61495 has better efficiency but will require much higher saturation current of inductor even for 4A load current

Q3. How much heat radiation area is required when using LMH61495-Q1 at 15V / 10A?

We are checking if LM61495 can drive 15V/10A output,

Q4. Do you have other options or recommended products for reducing the mount area on PCB?

Controller LM25141 for 15V/10A rail should save overall PCB area

0 Hirokazu Takahashi over 5 years ago in reply to Andy Chen

TI__Expert 8420 points

Hello Andy-san

Could you please reply regarding your answer for Q3 on the previous post below?

Q3. How much heat radiation area is required when using LMH61495-Q1 at 15V / 10A?

We are checking if LM61495 can drive 15V/10A output,

Best Regards,
Hirokazu Takahashi

0 Andy Chen over 5 years ago in reply to Hirokazu Takahashi

TI__Mastermind 33875 points

Hi Hirokazu,

Sorry for late!

We just confirm that LM61495 can support Vin : 22~30V to Vout 15V/10A conversion because of too high power loss. Pls try it with LM25141 controller solution.

B R

Andy

0 user4805041 over 5 years ago in reply to Andy Chen

Prodigy 80 points

Hello, Andy-san

This is Kawamura.
I contacted Takahashi san about this matter.

I understood that you recommend LM25141.
But I want to know if LM61495 can be used and how much heat it will generrate. (in 15V/10A output case.)

B R

Kawamura

0 Andy Chen over 5 years ago in reply to user4805041

TI__Mastermind 33875 points

Hi Kawamura,

We have data at 24VIN, 12VOUT, 10A, 400kHz.

Efficiency = 96%
PDISS_IC ~ 4.5W
EVM Theta-ja = 24C/W
Ta=40C
IC temp ~ 148C (rated for 150C).

so we think LM61495 probably cannot handle this condition at 400kHz.

B R

Andy

0 user4805041 over 5 years ago in reply to Andy Chen

Prodigy 80 points

Hello Andy san

Thank you for your reply.

I understood that LM61495 difficult to use this condition.
I have one more question.
How much current output can be used in this condition.

B R

Kawamura

0 user4805041 over 5 years ago in reply to user4805041

Prodigy 80 points

Hello Andy san

Could you answer my question?

How much current output can be used in this condition.

B R

Kawamura

0 Andy Chen over 5 years ago in reply to user4805041

TI__Mastermind 33875 points

Hi Kawamura,

as rough estimation, it can support 8.5A for below application:

22V~30V to 15V
PDISS_IC ~ 3.5W
EVM Theta-ja = 24C/W
Ta=40C
IC temp ~ 125C (rated for 150C).

B R

Andy

0 user4805041 over 5 years ago in reply to Andy Chen

Prodigy 80 points

Hello, Andy-san

Thank you for your reply.

I understood.

B R

Kawamura

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LM61495-Q1: 15V/10A