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TS3A4751 / Spectrum of Capacitance ,leakage current and Supply current

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Posted by Ryuji Asaka

on Dec 11 2012 06:38 AM

Expert1025 points

Hello E2E team,

I want to know below information for using TS3A4751.
If you can't open these information, please kindly let me know it.

1.Spectrum of Capacitance
Spectrum and variation in lot of "CNO(OFF)/CCOM(OFF)/CCOM(ON)

2.Spectrum of leakage current
Spectrum and variation in lot of "NO OFF leackage current / COM OFF leakage current / COM ON leakage current.

3.Relativity of Supply current and VI

In my understanding there is relativity between Supply current and VI.
So I would like to know supply current in our condition.
Our condition is as below.

V+:3V
VI:1.8V
For I/F using.

Best Regards,
Ryuji Asaka

All Replies

Posted by Ryuji Asaka

on Dec 12 2012 07:30 AM

Expert1025 points

Hello again,

I post more information.

Customer use 40pcs of TS3A4751 as chain.

One of the TS3A4751 has minimum capacitance and leakage current.

but if we use 40pcs that has big difference between Min and Max.

So , I would like to know distoribution.

Then calculate total capacitance and leakage current an supply current.

Concerning Supply current, when VI=0V and V=V+ supply current is minmmum in my understanding.

And supply current will be max when VI became half of V+.

If my understanding is incorrect please let me know.

Best Regards,

Ryuji Asaka

Posted by David Fischer

on Dec 12 2012 17:12 PM

Intellectual1305 points

Hi Ryuji,

I am looking into this and will have an answer for you shortly for the capacitance.

For leakage current, these min/max values are already provided in the datasheet.

Regards,

David

Posted by Ryuji Asaka

on Dec 12 2012 18:07 PM

Expert1025 points

Hi David,

Thank you.

I wait answer.

For Leakage current, there are big diffrence bitween "40 x min" and "40 x max".

Please see the below picture as my image.

Customer need like this information .

And how about supply current (Positive-supply current "data sheet P3") ?

There is max value of 0.75uA (Full temp) under the condition of " V+=3.6V and VIN=0 or V+".

Is this condition of max of supply current ?

If VIN =1.8V , will be supply current decreased from above condition's value ?

Best Regards,

Ryuji Asaka

Posted by Andrew Mason1

on Dec 18 2012 11:45 AM

Intellectual1390 points

Hello Ryuji,

I will be taking over this for David as he has urgent matters to attend to. Please my answers below:

1. This is still being looked into.

2. The leakage currents are specified in the datasheet as described above. Customer can expect no more leakage than the max value across temp and process. Are these values not acceptable to the customer? Why does the customer need this data?

3. Supply current has no dependency on the input voltage to the switches. regardless of if there is 1 V 2 V etc on the switches the same voltage is applied to gate of the switch to turn it on.

Regards,

Andrew

Posted by Ryuji Asaka

on Dec 20 2012 05:18 AM

Expert1025 points

Hello　Andrew,

Thank you for the information.

I got informaion of input capacitance and supply current.

And sorry for late reply and my infuccient explanation for leakage current.

I'm checking further background...

And I will post again tomorrow.

Best Regards,

Ryuji Asaka

Posted by Ryuji Asaka

on Dec 21 2012 06:34 AM

Expert1025 points

Hello Andrew,

I'm waiting customer's reply.

I post again after get the reply.

Best Regards,

Ryuji Asaka

Posted by Ryuji Asaka

on Dec 27 2012 01:32 AM

Expert1025 points

Hello Andrew,

Sorry for the late reply.
Please see the attached pdf file and below as diagram and detail of background.
If there are any questions please let me know.

0027.TS3A4751 diagram.pdf

-------------------------------
Customer's request Dead Line：
8th/Jan/2013

Circuit description:

Customer measures DUT off Leakage current by this circuit.
1 of the “DUT-Current Measurement Unit” line is turned on when measuring
DUT off leakage current. Other lines are turned off.
If total Leakage Current is over 110nA , current measurement accuracy will be Low.

When total lekage current is over 110nA, they can separate circuit.

Request Data:

Customer' request is 3σ of below Leakage current parameter at over 10 lot.

Data Condition, Ta=85℃, V+=3.6V

-No off leakage current

-COM off leakage current

-COM on leakage current

Target spec :

Analog Switch TOTAL Leakage Current≦110nA/1 current measurement unit

TOTAL Leakage current =1 * Ino(off) + 41 * Icom(off) + 1 * Icom(on)

If 3σ=2nA, customer’s calculation is as below (for example).

1*2nA(Icom(on))+1*18nA(Icom(off)max)+40*2nA(Icom(off))+1*2nA(Icom(on))=102nA

Others:

I got comment which customer want to use TS3A4751 as possible.

We explained that we can’t guarantee request data. And customer accepted it.

-------------------------------

Best Regards,

Ryuji Asaka

Posted by Ryuji Asaka

on Dec 27 2012 02:55 AM

Expert1025 points

Hello Andrew,

Complement about request data.

I posted that request data is distribution.

But I confirmed 3σ value is ok as customer's request data.

Then, customer can estimate total leakage current.

For example,

-No off leakage current : 3σ =2nA

-COM off leakage current : 3σ =2nA

-COM on leakage current : 3σ =2nA

Best Regards,
Ryuji Asaka

Posted by Andrew Mason1

on Jan 03 2013 16:32 PM

Intellectual1390 points

Hello Ryuji,

I have checked char data and it correlates with the datasheet for the leakage values specified. Customer should plan on worst case leakage currents specified in datasheet as it is very possible to get parts that have near the max leakage.

This data is taken across temperature and corners.

Regards,

Andrew

Posted by Ryuji Asaka

on Jan 07 2013 04:41 AM

Expert1025 points

Hello Andrew,

Thank you for checking the char data.

I will check about handling of this issue.

And if need, I will post again.

Best Regards,

Ryuji Asaka

Posted by Ryuji Asaka

on Jan 23 2013 06:08 AM

Expert1025 points

Hello Andrew,

I got new information from customer about design of TS3A4751.
Could you please kindly consider to provide 3σ data of leakage current ?

Attached file is image of the dividing circuit for reduce the total leakage current.

4527.TS3A4751_dividing cercuit by switch.pdf

1. There is no competitor of TS3A4751.
Competitor don't have switch of 4ch/2mm sq size.
So, they already started design by using TS3A4751.

2.If customer consider leakage current as 18nA for all devices, they must divide circuit.
Please see the attached file Page 1.
In this case, they need more "8 control signal" for On/Off control of switch from "FPGA".
But, they don't have margin of FPGA pin assign currently.

3.If we can provide 3σ data as lower than 18nA, they can reduce control signal.
Please see the attached file Page 2.
In this case, 3σ is 10nA.
Customer can reduce dividing number.
Thus, customer can reduce control signal from FPGA.

4.When we can provide 3σ data and customer will design circuit by that data, there is out of device from 3σ.
Customer has counter plan.
They will take screaning themselves.

5.Could you please kindly consider to provide 3σ data of leakage current ?
If there are any requirement for providing the data , please let me know.

*dividing number of attachment is image.

I would like to tell that we will provide 3σ data, customer can reduce pin assign of FPGA.

Best Regards,

Ryuji Asaka

Posted by Ryuji Asaka

on Feb 03 2013 22:45 PM

Expert1025 points

Andrew san,

Sorry for bothering you.

I understan'd that we should use leakage current as datasheet data due to there is max data.

But , Are there any possibility of getting leakage current distribution data to me?

- If no, please kinldy let me know the reason ?

Then I will explain to our customer.

- If yes, please kindly let me know the condition for getting data.

Then, I will get the data for getting distribution data.

Best Regards,

Ryuji Asaka

Posted by Andrew Mason1

on Feb 12 2013 09:19 AM

Intellectual1390 points

Hello Ryuji-san,

I apologize for the delay in response to this. I have looked into the char data and discussed with the team on how this data is taken. There is no distribution data taken for this parameter. It is measured across temp and process to find a maximum value. A "buffer zone" is then added to these values to ensure no units reach the customer outside of datasheet values.

Regards,

Andrew

Posted by Ryuji Asaka

on Feb 13 2013 18:10 PM

Expert1025 points

Hello Andrew san,

Thank you for the information.

I understood the situation of this parameter.

I will explain it to customer.

Best Regards,

Ryuji Asaka

Posted by Ryuji Asaka

on Feb 13 2013 19:53 PM

Expert1025 points

Hello Andrew san,

Sorry again.

Can I have the leakage current value of "buffer zone" ?

Best Regards,

Ryuji Asaka

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TS3A4751 / Spectrum of Capacitance ,leakage current and Supply current