VR500 PMIC SW1 Current Insufficient For LS1028A Applications

jimmymm — Mon, 01 Jun 2020 22:22:16 GMT

I am in the process of implementing the power scheme to our custom LS1028A application. I saw from the LS1028A Reference Design Board that NXP utilizes and recommends the VR500 PMIC, specifically the MC34VR500V9ES, for the LS1028A application. In the VR500 datasheet, the SW1 output is described to supply the LS1028A's VDD core (1.0V/0.9V) with a max current of 4.5 Amps.

According to the LS1028A Design Checklist "Table 7. Typical use case power at 65 C", every LS1028A configuration exceeds the current available from the VR500 SW1 output. I find it unusual that the PMIC recommended for this processor is not capable of providing sufficient VDD current under load.

Is this the right PMIC for the LS1028A, or is there another PMIC available that is capable of providing sufficient power without having to use another separate switching power supply?

Re: VR500 PMIC SW1 Current Insufficient For LS1028A Applications

ufedor — Tue, 02 Jun 2020 04:57:36 GMT

It is reasonable to refer to the QorIQ LS1028A Reference Design Board Reference Manual, 2.2 Power supplies where it is shown that VDD is provided by LTC7151S:

and the RDB schematics:

LayerscapeのトピックVR500 PMIC SW1 Current Insufficient For LS1028A Applications

VR500 PMIC SW1 Current Insufficient For LS1028A Applications

Re: VR500 PMIC SW1 Current Insufficient For LS1028A Applications