topic LPC55S26JEV98 || Power Supply in LPC Microcontrollers

LPC55S26JEV98 || Power Supply

JyotiVaishnav — Mon, 07 Aug 2023 12:39:20 GMT

Hello Team,

We are using an LPC55S26JEV98 processor in our design.

Following below mentioned connections we did in our design for power rails.
VDD_1 / VDD_2 / VDD_3 / VDD_4 - are connecting to 1V8
VDD_PMU / VDDA / VBAT_DCDC / VBAT_PMU - are connecting to 3V3

We want to know that there is any problem or issue to connect VDD_PMU / VDDA / VBAT_DCDC / VBAT_PMU the mention supplies to 3V3 voltage level.

Re: LPC55S26JEV98 || Power Supply

TwoBias — Mon, 07 Aug 2023 13:37:22 GMT

Hi,

you should not connect VDD_PMU to 3,3V.

It is core supply and maximum voltage is 1,26V.

You should connect it with the DCDC output path and FB Pin.

Re: LPC55S26JEV98 || Power Supply

xiangjun_rong — Tue, 08 Aug 2023 02:39:05 GMT

Hi,

As TwoBias said, for the VDD_PMU power supply pin, we suggest you use internal DC/DC converter for the VDD_PMU power supply as the following Fig. The VDD_PMU power supply input voltage is from 1.1V to 1.2V, which can be controlled with software based on the core frequency.

It is okay that

VDD_1 / VDD_2 / VDD_3 / VDD_4 - are connecting to 1V8
VDDA / VBAT_DCDC / VBAT_PMU - are connecting to 3V3

Hope it is helpful

XiangJun Rong