Part Number: TCA9517
Hello TI-Team,
we want to use the TCA9517 and have a question regarding the voltage levels.
Is it allowed to use a different pull-up voltage for SCLB/SDAB than the supply voltage VCCB?
In our design:
- VCCB (= PWR_1 in picture) is supplied separately
- Pull-ups on SCLB/SDAB (= PWR_2 in picture) use a different voltage
- We are planning to use two separate 3.3V rails with different power-up sequences. 3.3V pull-up Voltage ramps up before VCCB supply. The current for the pull upvoltage is only <40mA this is why we want to use a different supply
- Additionally, we are considering using 5V for VCCB (PWR_1) as an alternative option
Our power-up sequence is:
Option 1: 1.8V (VCCA) => PWR_2 (pull-up voltage for SCLB/SDAB) => PWR_1 (VCCB)
Option 2: 1.8V (VCCA) => PWR_1 (VCCB) => PWR_2 (pull-up voltage for SCLB/SDAB)
Is this configuration valid, or are there any concerns we might have overlooked?
Thank you for your support.
Best regards,
Benedikt
