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Schuyler
Schuyler
Associate III
June 1, 2023
Solved

use the EH pin of ST25DV for low-power MCU (stm32L4)

  • June 1, 2023
  • 16 replies
  • 4670 views

I want to use the EH pin of ST25DV to obtain energy through RF and power supply data transmission for low-power MCU (stm32L4). Can this scheme be realized? What should I do?

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Best answer by Rene Lenerve

Hi @帅 罗​​,

This can be done by connecting the EH pin to the VCC of the STM32L476. Don't forget to connect the ground of the ST25DV and of the MCU. If you want to communicate through I²C between MCU and ST25DV you will also need to connect the VEH of the ST25DV to the VCC of the ST25DV. Take into account that the current provided by the EH pin will be limited by the field provided by the RF.

You will find some documentation on Energy Harvesting with the following documentations:

ST25DV DataSheet

AN4913: Energy harvesting delivery impact on ST25DV-I2C Series

AN5233: Energy harvesting with ST25DV-I2C series Dynamic NFC Tags

Kind Regards.

16 replies

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Schuyler
SchuylerAuthor
Associate III
June 29, 2023

If the EH pin current is too small to run the MCU, can I add a power module, such as LTC3108-1, BQ25570 or MAX17710, to transfer the small power energy emitted by the EH pin and provide stable power output to make the MCU run stabilities?

Schuyler
SchuylerAuthor
Associate III
July 18, 2023

@JDEME 

Hi,

According to your description, what should I do to make the energy of EH pin drive stm32l476 properly? Can you give a reference diagram of the correct connection? I don't know exactly what to do.

Regards,

Schuyler
SchuylerAuthor
Associate III
July 21, 2023

Hi，

@JDEME 

the EH is used the X-NUCLEO-NFC07A1 ST1connector jumper must be correctly set. But I don't know how to set it. Can I use the energy from the EH pin to power the L4 through the output pin of the LTC3588?

Regards,

Schuyler
SchuylerAuthor
Associate III
July 27, 2023

Hi，@JDEME 

Do you want to connect the EH pin to PC5? I have disconnected USB POWER, how do I get power through the EH pin？

JDEME
JDEME
ST Employee
September 27, 2023

Hello,

Did you cut the STlink ? Did you measure the current delivered by the EH pin  and  checked the balance between the MCU power consumption versus the power delivered by your phone  ?

BR

Schuyler
SchuylerAuthor
Associate III
October 12, 2023

Hi @JDEME 

Yes, I'm not powering the ST-link, I want to power the MCU using the EH pin, but how can I reduce the power consumption? I am currently based on EH code in EN.X-Cub-NFC7, how to use the energy provided by the mobile phone to wake up the MCU?

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