TPS22922: Current consumption difference

Miatsu Okitsu

Part Number: TPS22922

Tool/software:

Hello,

In addition to TPS22922BYZPR, I have 3 more alternative part in the BOM, which are TPS22924BYZPRB, TPS22964CYZPR and TPS22964CYZPT. It is up to the PCB assembly house which component to be used.

Now I have 2 PCBA which has different marking on. They are 44J5NF and 37Q3Z5. (The marking is so tiny. My reading might not be correct)

When the pin "ON' ="L" and 2.3V is applied to the pin "Vout", I saw difference between these 2. Please see below for detail.

Here is the detail condition.

1.) pin "Vin" = 3.3V, pin "ON" = 0.0V

2.) pin "Vout" is connected to the Vcc of another IC through a Murata ferrite bead BLM03PX330SN1D. (+ Vcc filtering caps)

3.) Vcc of this another IC has 2.3V on this pin even though the TI load switch is off. (because there is another voltage applied to this IC from another voltage path)

4.) I could see about 30mA total current consumption difference. Pin "Vout" of 44J5NF = 1.576V, pin "Vout" of 37Q3Z5 = 2.262V

5.) If I remove this ferrite bead, both current consumption becomes the same.

Could you explain why there is difference in between? I guess this is whether the load switch has the reverse current protection or not.

If so, does this damage the load switch if there is no reverse current protection?

Best Regards,

Miatsu

over 1 year ago

0 Nicholas Petersilge over 1 year ago

TI__Intellectual 2730 points

Hi Miatsu,

you provided 4 part numbers, are all of these 4 parts having this behavior?

Thanks,
Nicholas Petersilge

0 Miatsu Okitsu over 1 year ago in reply to Nicholas Petersilge

Prodigy 50 points

Hi Nicholas,

2 components with the reverse current protection shows consistent current regardless of the ferrite bead. But 2 components without the reverse current protection draw 30mA more current then the ferrite bead is on. I guess this 30mA flows into the pin "ON" if the component does not have the reverse current protection.

I plan to externally apply 2.3V to the pin "ON" for these components and measure how much current goes into the pin "ON". I would like to know whether my guess is correct/reasonable or not.

Regards,

Miatsu

0 Miatsu Okitsu over 1 year ago in reply to Miatsu Okitsu

Prodigy 50 points

Hello Nicholas,

I have confirmed that this 30mA is caused by with or without the reverse current protection. Due to our manufacturing process, we need to apply this 2.3V onto the pin "Vout".

Does this damage this switch if there is no reverse current protection?

Thanks,

Miatsu

0 Nicholas Petersilge over 1 year ago in reply to Miatsu Okitsu

TI__Intellectual 2730 points

Hi Miatsu,

Could you draw a diagram of how you are setting up the device as well as the measurements you are seeing such as the direction of current coming through the ON pin so I could get a better understanding of your problem?

Best Regards,
Nicholas