LMQ61460-Q1: IC application problem

Boyan Lu

Expert 6015 points

Part Number: LMQ61460-Q1

Hi Team

I would like to ask if the RFBB is scaled down to only 2k ohms?

Boyan

over 1 year ago

0 Jimmy Hua over 1 year ago

TI__Guru 50120 points

Hi,

The recommendation for 10kOhm - 1MOhm applies onto to the top feedback resistor (R_FBT). You can set the RFBT in the middle of this range (100kOhm) and pick the appropriate bottom resistor for your desired output voltage regulation.

Regards,

Jimmy

0 Boyan Lu over 1 year ago in reply to Jimmy Hua

TI__Expert 6015 points

Hi Jimmy

Since the customer has designed a lower resistance value in other cases, what would be the problem if I had designed the top resistance to be 16kOhm, the lower resistance design 2kOhm?

Thanks.

Boyan

0 Jimmy Hua over 1 year ago in reply to Boyan Lu

TI__Guru 50120 points

Hi Boyan,

No that shouldn't be a problem since the top resistor is still within the expected range. Just note that by using the lower valued resistors this would result in higher current consumptions at light load conditions.

Regards,

Jimmy

0 Boyan Lu over 1 year ago in reply to Jimmy Hua

TI__Expert 6015 points

Hi Jimmy

Ok!

Thanks.

Boyan

0 Jimmy Hua over 1 year ago in reply to Boyan Lu

TI__Guru 50120 points

Thank you for using the E2E forum. I will be closing this thread now. If you have any further question, please reply back to this thread and it will reopen for further support.

0 Roy Chou1 over 1 year ago in reply to Jimmy Hua

TI__Genius 14305 points

Hi Jimmy,

I would like to check whether we can use hundred of ohm resistance as feedback resistors. In addition to power consumption, does it cause system unstable or ?

Regards,

Roy

0 Jimmy Hua over 1 year ago in reply to Roy Chou1

TI__Guru 50120 points

Hi Roy,

The validation team has not tested with that low of a feedback resistance value. What is the reason why customer needs to go that low instead of picking the mid kOhm resistors that are commonly used and available?

Regards,

Jimmy

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LMQ61460-Q1: IC application problem