TPS1H100-Q1: CS settling time inquiry

Andy Snawerdt

Part Number: TPS1H100-Q1

Hi Team,

Happy holiday's! Hope everyone got some time to relax and spend with family!

My customer is using the TPS1H100-Q1 and is noticing a large discrepancy in what they're calling the "valid time window" for taking their CS measurement under two different load condiitons:

Case 1 - Iout = 2A, Duty Cycle = 10%:

Case 2 - Iout = 2A, Duty Cycle = 12%:

As you can see, they've noticed an 80us discrepancy between a 12% and 10% duty cycle change off of a 2A load. Note that the reason we believe we are seeing Vcs hit it's fault voltage initially is because the load is being provided by an e-load in CC mode, which I've been informed can interfere with the CL circuitry on start-up.

Can someone help me understand why we're seeing such a large discrepancy in this "valid time window" between these two load conditions?

Thanks!

- Andy

over 3 years ago

+1 Shreyas Dmello over 3 years ago

TI__Mastermind 32650 points

Hi Andy,

We do not recommend the use of eLoads set in constant current mode for this system. Please perform the test with a constant resistance.

I am also not certain what you are referring to as a "valid time window". If the duty cycle increases and the effective "capacitance" of the system remains the same then the turn on inrush event lasts for the same time between the two tests. The waveforms seem to also behave as described. Then with a longer duty cycle, it makes sense that you will see a longer time during which CS is your expected value (the DC current through a enabled device).

Let me know if I am missing something.

Here is an FAQ about using eLoads with High Side Switches for more information: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1021866/faq-why-does-my-e-load-cause-my-high-side-switch-to-shut-down

Thanks,

Shreyas

Power management

Power management forum

TPS1H100-Q1: CS settling time inquiry