TCA9517: TCA9517 leakage current from VCCA to VCCB

Nanfang Liao

Intellectual 2085 points

Part Number: TCA9517

Hello Team,

My customer uses TCA9517 for I2C application, both VCCA and VCCB are 3.3V power supplys. When VCCA is powered on first, and there is no power supply on VCCB, they find there is 0.8V voltage on VCCB, if they remove TCA9517, this voltage disapears, so it means that the 0.8V voltage comes from VCCA. Does our part have this feature? Can we fix this problem?Thanks.

Regards,

Nanfang

over 8 years ago

0 fhoude over 8 years ago

TI__Mastermind 23116 points

Hello Nanfang,
I would like to see how this part is connected, in other words a detailed schematic. Is Vccb separate from the SDAB/SCLB driving supply? You may be back biasing the part from the SDA/SCL lines.
-Francis Houde

0 Nanfang Liao over 8 years ago in reply to fhoude

TI__Intellectual 2085 points

Hello Francis,

You can check the schmatic below, i think this problem should be not relative with other curcuit, can you help to double check this problem in the lab? Thanks

Regards,
Nanfang

0 fhoude over 8 years ago in reply to Nanfang Liao

TI__Mastermind 23116 points

Hello Nanfang,
I have verified in the lab that there is a little leakage on the device that can raise the voltage on the order of 800mV. I was seeing 4-8uA of leakage. This is low. What are the customers worried about??? If they pull the EN low than that goes away completely.
-Francis Houde

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TCA9517: TCA9517 leakage current from VCCA to VCCB