TS5A22362: About Measurement circuit of ON/OFF leakage current

Hi Parker-san,

Thank you for your prompt reply and detail information.

I understand that measurement circuit is [My image(Modified version)].

And, I have one more question.

I understand that ON/OFF leakage current(±375uA at Full temp) contains the following elements.

-leakage current of NO & NC pins(open switch)

-leakage current of other internal circuit

So, it is the leakage current of overall device.

Is my understanding correct?

[My image(Modified version)]

Regards,

Hide

Hi Parker-san,

Thank you for kind support.

I have ono more question.

I understand that the leakage current of other internal circuit(for example, IN pin of internal logic etc.),

This is included in Positive supply current(ICC).

Is my understanding correct?

Regards,

Hide

Hi Parker-san,

Thank you for the detail information.

I greatly appreciate your cooperation.

Regards,

Hide

Hi Parker-san,

I apologize for my frequent contacts.

I have one more question.

If the voltage difference between VCC and VCOM is low(or same voltage), does INC(off) increase?

Our customer confirmed INC(off) of 30pcs at the following condition*.

* It is different from the measurement conditions in the data sheet.

At the result, One INC(off) of TS5A22362(Device1) is more than 100uA and other ICs(29pcs) is several dozen(Around 10uA to 20uA).

However, Device1 also has different INC(off) depending on the voltage conditions.

[Measurement conditions of Device1]

Case1:if VCC=VCOM=5V, INC(off) is more than 100uA

Case2:if VCC=5V, VCOM=4.8V, INC(off) is several dozen(10uA to 20uA)

[Result image]

We would like to know why only one has a high INC(off) value.

Could you please let us know if you have any information?

Regards,

Hide

Hi Hide,

Can you confirm the following for me:

1.  What is the test setup of this test?
   1. What are the control voltages (voltage at INx pins) at?
   2. What temperature are you testing at?
   3. What voltage is the NC pin(s) at
   4. Are you measuring both NC pins are just 1 for the test.
2. Was only the first part you tested having this issue? If so could you please test a few good units and retest the bad unit to see if the issue is still occurring?

In general the leakage is coming from 2 places: The ESD diodes on the I/O channel (which is the primary source of leakage as most leakage comes from here) and a very small subthreshold leakage through the switch directly. There shouldn't be a large increase for a difference in 200mV if VCC and V_NC are unchanging (as the impedance between COM and NC when open switch is very high) so this is unusual. So please if you could answer my questions above so that I fully understand the test setup as well as possibly retesting the bad unit (after a few good units have been tested to ensure that the test setup is functioning as intended) to see what the issue could potentially be, if any.

Please let me know!

Best,

Parker Dodson

Hi Parker-san,

I apologize.

There was a mistake in my information(OFF leakage current values).

[Abnormal phenomenon]

OFF leakage current of NC1 pin(IOFF(NC1)) is very high current.

-Around 300 to 500uA at VCC=5V, VCOM=5V

-Around 10uA at VCC=5V, VCOM=4.8V

Bye the way, NC2,NO1,NO2 of same units are correct OFF leakage current(around 10nA).

And, other units(29pcs) are correct OFF leakage current.

I confirmed the test conditions.

Please refer to [Test conditions].

[Your questions]

1.  What is the test setup of this test?
   1. What are the control voltages (voltage at INx pins) at? -> 5V
   2. What temperature are you testing at? -> around 25℃
   3. What voltage is the NC pin(s) at -> don’t confirm NC1 pin voltage
   4. Are you measuring both NC pins are just 1 for the test.->NC1 is abnormal OFF leakage current and other pins(NC2,NO1,NO2) are correct current(around 10nA)
2. Was only the first part you tested having this issue? If so could you please test a few good units and retest the bad unit to see if the issue is still occurring?

->” OFF leakage current of NC1 pin is 300 to 500uA” is always confirmed so the issue is still occurring.

[Test conditions]

I understand that OFF leakage current of NC1 pin of abnormal.

Is my understanding correct?

And, I would like to know this cause.

(For example, NC1 pin is damaged etc.)

Could you please let us know your opinion?

Regards,

Hide

Hi Hide,

The voltage on the NC1 pin is going to have an effect on the leakage value there. Can this please be measured? The test conditions have a voltage on NC1 during NC1 off leakage current.

As for damage - it is possible that there could be damage, but what the damage is or how it was caused is a bit hard to determine with the current information. It does seem to be not working correctly. But the following information would be great:

1. I do need the voltage on the NC pin during off leakage testing as this is determined by the spec - and I need to confirm that a similar setup is being used so that I have a benchmark of what should be happening.

2. Is there any other performance issues besides the off leakage - EOS from unexpected transients during testing or too large of an ESD strike could cause damage but typically there would be more effects than only higher. A helpful test would be to see if the off isolation is lower than expected as well as that can look at how well the switch is isolating in the off state. 

So it does seem a little off how the part is acting but I do need the voltage at the NC1 pin for leakage for that pin (if it is floating than that's not what our spec is looking for - as we only use the open configuration during on leakage current measurement). Also other effects on performance on this part on this pin would help point to if or if not there is damage.

Please let me know!

Best,

Parker Dodson

Hi Parker-san,

Thank you very much for your help.

I will contact you again after I get new information.

Regards,

Hide

Hi Parker-san,

Thank you for always kind support.

I understand.

Regards,

Hide

Thanks Hide!