TPS82740A: TPS82740A Quiescent Current

Kevin Bachovchin

Part Number: TPS82740A
Other Parts Discussed in Thread: TINA-TI

Hello,

On page 5 of the datasheet for TPS82740A, it lists the operating quiescent current with the "device not switching" and the "device switching". What controls whether the device is switching or not? EN = VIN and CTRL = GND, and IOUT = 0 for both rows 1 and 2, yet for row 1 it says "device not switching" and row 2 "device switching"

Also I tried simulating the TINA-TI model on the webpage
www.ti.com/.../TPS82740A

I removed the load from the model and connected the CTRL pin to GND instead of to VIN, but I'm getting 10 microamps of input current in that case, not the 500 nanoAmps listed in the datasheet. Why is this? Is there something else that needs done to the model to obtain the 500 nanoAmps quiescent current?

Thanks,

Kevin

over 4 years ago

0 Chris Glaser over 4 years ago

TI__Guru*** 144420 points

Hi Kevin,

Let me point you to my white paper, found on the product page, which discusses this topic in detail: https://www.ti.com/lit/an/slyt412/slyt412.pdf

I'm not sure if the models accurately model the Iq. But if you can post your TINA file, I can take a look at it.

0 Kevin Bachovchin over 4 years ago in reply to Chris Glaser

Expert 1060 points

TPS82740A_SteadyState.tsc

Chris,

Thanks for your white paper on quiescent current. I will read it.

In the meantime, here is my TINA-TI model (this is the same as from TI's webpage, with the only changes being that the load was removed and the CTRL pin was connected to GND (instead of VIN).

Also, what controls whether the device is switching or not? EN = VIN and CTRL = GND, and IOUT = 0 for both rows 1 and 2 in the table, yet for row 1 it says "device not switching" and row 2 "device switching"

Thanks,

Kevin

0 Chris Glaser over 4 years ago in reply to Kevin Bachovchin

TI__Guru*** 144420 points

Hi Kevin,

The paper should explain the difference between switching and non-switching.

The TINA model states that the Iq is not modeled.

I you are trying to estimate the current consumption of the device, I suggest using the efficiency curves in the D/S.

Power management

Power management forum

TPS82740A: TPS82740A Quiescent Current