Hi!
We are reaching out regarding our device utilizing the DS90UB949-Q1. Our device operates in two modes: normal and sleep mode. In the previous hardware revision, the RX_5V was connected to a power rail that was deactivated during sleep mode. However, in the latest hardware revision, we have modified the connection so that RX_5V is connected to a power rail that stays active during sleep mode, while all other power rails to the DS90UB949-Q1 are deactivated (including the CPU connected to the serializer, which is completely powered down).
Upon observation, we have noticed an increased current consumption during sleep mode, approximately 50-60mA higher than previously recorded. Our initial assessment suggests that this increase may be attributed to the RX_5V pin remaining supplied with 5V during sleep mode. Datasheet specifies a maximum current consumption of 50mA on RX_5V.
We have several inquiries regarding this matter:
- Could you kindly provide us with the internal diagram for the RX_5V pin?
- Are there any potential drawbacks or reasons against utilizing RX_5V pin connected to an active 5V supply rail while all other rails to the DS90UB949-Q1 are deactivated, aside from the increased current consumption?
- Could there be any issues related to the serializer lock time, considering that "Figure 3. Serializer Lock Time" in the datasheet indicates that RX_5V comes after VDD, VDDIO, and PDB? In our case, RX_5V is the first to become active after transitioning from sleep mode to normal mode. Although we haven't observed any suspicious behavior with the serializer, we seek clarification on this matter.
Your insights and guidance on these questions would be greatly appreciated. Thank you for your attention to this matter.
Best regards,
