VSYS BEHAVIOR STRANGE

[MarckMarfori]

I configured VBUS with a 1500mA limit. In theory, VSYS should deliver something similar to this.
The VSYS output is 5V; it powers some LDOs in my project, which consequently power the uC and cellular modem (higher consumption).
My project's current consumption is around 600 mA (peak).
Without the battery connected, my VBUS is fully capable of powering my entire circuit, but for some reason, VSYS keeps varying, with power supply behavior dropping, causing the voltage to drop and then rise as a means of current compensation.
Is this something I need to configure? If so, where do I do it?

[Ressa]

Hi,

Thanks for contacting us. VSYS output is not a regulated voltage and it follows the supply source. So you might see output variation if the main source can vary. As you mentioned if you are regulating the VSYS output with other LDOs for your circuit, then the LDO outputs should be important to you as they are suppling the MCUs and rest of the circuits. I can also have a look at your circuit if you could provide it. 

Best regards,
Ressa