VBAT Pin Availability for External Battery Connection (RTC)

LPWAN Modules / EVBs RAK3172
1

I am currently working on a project that involves integrating a real-time clock (RTC), I am looking to connect an external battery to the VBAT pin to ensure uninterrupted power to the RTC. But I could not find the VBAT pin on RAK 3172, So can someone please clarify the availability of the VBAT pin on RAK3172.

Thanks in advance

2

Welcome to RAK forum @joshypjt .

The VBAT of RAK3172 is internally connected to VDD.

image
image972×299 15 KB

3

Thank you so much for your quick support

4

Hi,
As per the attached screen shot (took from RAK3172_STM32CubeWL_SDK_1_3.PDF - RAK3172 LoRa P2P on STM32CubeIDE - LPWAN Modules / EVBs / RAK3172 - RAKwireless Forum) we were able to configure LSE for RTC, so does it mean we have crystal oscillator with 32.768Khz connected internally to the MCU pins?
In addition, we are currently in the design phase and we find that having access to the detailed schematic will significantly contribute to a clearer comprehension of the internal components and their interconnections,
So can you please share the RAK3172 schematic?

RTC clock
RTC clock1061×560 76.8 KB

Thanks in advance

5

Hi @joshypjt ,

There is a 32.768Khz oscillator internally. Btw, I sent you a message in your forum inbox.