LP3907: schematic recommend

James Zhan

Part Number: LP3907

Hi,

Could I just keep the unuesd PIN on LP3907 floating? or do you have a better recommendation for the unused PIN? Do I need to pull up to connect them to the ground?

NOTE： X means unused.

over 6 years ago

0 Richard Solarski over 6 years ago

TI__Genius 10885 points

Hi James,

Please connect ENLDO1, ENLDO2, and EN_T to GND instead of VCC if LDO1 and LDO2 are unused. As long as those enable pins are connected to GND, the outputs for LDO1 and LDO2 can be left floating.

For the i2c, it might be beneficial to tie them to VCC with pull-up resistors just in case noise could couple to those pins.

Best Regards,
Rick S.

0 James Zhan over 6 years ago in reply to Richard Solarski

TI__Expert 4365 points

Richard,

Thanks for you quick response.

One more question: If I don't need to use the BUCK2, could I just connect the EN_SW2 to GND, and left V-BUCK2 and V-FB2 floating?

0 Richard Solarski over 6 years ago in reply to James Zhan

TI__Genius 10885 points

Hi James,

Yes, this would be OK. You could also connect FB2 to GND as well.

Since EN_T can enable all regulators, it should be connected to GND if any regulator is missing external components.

Best Regards,

Rick S.

0 James Zhan over 6 years ago in reply to Richard Solarski

TI__Expert 4365 points

Hi Richard,

Thanks for the information.
Could I just tie I2C to GND with pull-down resistors?

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LP3907: schematic recommend