LMR14030-Q1: How much current flow from RT/SYNC pin?

Yuta Kurimoto

Genius 10620 points

Part Number: LMR14030-Q1

Hello Team,

I'm Yuta Kurimoto TIJ FAE.

I have one question about the RT/SYNC pin of LMR14030SQDDARQ1 (non-spread spectrum)

Q. How much current flow from RT/SYNC pin?

If it's constant current source, let me know the value of current

If it's constant voltage source, let me know how much capability of current.

Thanks,

Yuta Kurimoto

over 6 years ago

0 Andy Chen over 6 years ago

TI__Mastermind 34045 points

Yuta-san,

At RT mode, the RT/SYNC pin is biased with 0.5V internally, RT ressitor should be bigger than 6.8K for most application case. bias current can be calculated by 0.5V and RT resistnace.

0 Yuta Kurimoto over 6 years ago in reply to Andy Chen

TI__Genius 10620 points

Hello Andy,

Thanks for your quick response.
At the RT mode, When the 6.8k ohm resistor is connected, the current flow from RT/SYNC pin can be calculated as 0.5/6.8k = 73.4uA?

Yuta Kurimoto

0 Andy Chen over 6 years ago in reply to Yuta Kurimoto

TI__Mastermind 34045 points

Yuta-san,

Yes, RT/SYNC pin source current can be calculated by this way.

0 Yuta Kurimoto over 6 years ago in reply to Andy Chen

TI__Genius 10620 points

Hello Andy,

I got additional question about this topic.

Q. How much capability of maximum current flow from RT/SYNC pin?

In the customer's system, they will connect MCU I/O pin and LMR14030-Q1 RT/SYNC pin. So if RT/SYNC pin can have large source current, It may damege MCU.

Thanks,

Yuta Kurimoto

0 Andy Chen over 6 years ago in reply to Yuta Kurimoto

TI__Mastermind 34045 points

Yuta-san,

As check it with designer, the maximum source current on RT pin is about 170uA, pls check if it will damage MCU I/O port.

0 Yuta Kurimoto over 6 years ago in reply to Andy Chen

TI__Genius 10620 points

Hello Andy,

Thank you!

Yuta Kurimoto

Power management

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LMR14030-Q1: How much current flow from RT/SYNC pin?