• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 35 subscribers
  • Views 374 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TCA9517-Q1: Leakage Current of Side A and Side B

Jayjit Yadav
Prodigy 180 points

Hello,

we are using side A VCCA (Input) for 3.3v Master Controller and Side B VCCB (Output) for Slave RTC but when we are not communicating or Controller shutdown (3.3V Off ) at that time leakage current through the VCCB is approximately 1.6mA which is quit bigger for our application because we are using super capacitor backup supply for VCCB.

but if we connected controller side to VCCB and Slave side to VCCA and Controller shutdown (3.3V Off )  we got Leakage current of 28uA which is ok for us. but is it ok to connect in this Manner ?? 

  • 0
    TI__Guru* 81031 points

    Hey Jayjit,

    Are you saying that A side is SDA/SCL's pull up resistors are floating while VccA and VccB are powered and enabled? This would be the only way I could reasonably see that there would be mA of leakage current through our device when there isn't communication.

    If I am misinterpreting this, could you please show us a block diagram (pull up resistors tied to what power supplies and such) for me to get a better grasp of the set up. At the moment I don't understand what is powered and what may be floating.

    VccA of our device sets up threshold values for the device and VccB sets up threshold values and also drives the logic, so VccB typically has more current draw.

    -Bobby