TPS7A57: LDO parallelism

Bharati Aravatagi

Part Number: TPS7A57

Tool/software:

Hi,

I have high current requirement for one of the sensitive applications and I am planning to use two TPS7A5701RTER LDOs in parallel to fulfill current requirement.

I was planning to design this application as per TIDU421 application document by TI where Opamp is used for balancing the outputs.

But in TPS7A5701RTER datasheet, there is one application mentioned in page 65-66 where Opamp is not considered when connecting two LDOs in parallel. As per my understand , since this has SNS pin and REF pin for current sense, there is no need of Opamp.

Or you recommend using Opamp when we use two TPS7A5701RTER in parallel as per TIDU421?

Thanks

Bharati

6 months ago

0 Stephen Ziel 6 months ago

TI__Mastermind 37015 points

Hi Bharati,

We have developed significant collateral to parallel the TPS7A57 using ballast resistors instead of using an op-amp. Please take a look at these resources.

Parallel LDO Collateral:

Parallel LDO Calculator

13.5A low-noise high-accuracy LDO Reference Design

Parallel LDO Architecture Design Using Ballast Resistors

Comprehensive Analysis and Universal Equations for Parallel LDO's Using Ballast Resistors

We do not have resources readily available using an op-amp approach for the TPS7A57. You would have to look into developing this yourself using TIDU421 as a guide. You would use the SNS pin in the TPS7A57 instead of a FB pin as you see in the TIDU421, but that is about all of the guidance we can offer as we do not have this solution readily developed.

Thanks,

Stephen

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TPS7A57: LDO parallelism