NFC Reader ST25R95

Dalik · ‎2023-09-27

1. NFC ST25R95 Can I process if I don't use the MCU to control?

2. Can I boot up voltage to 10V for pin TX1 and TX2 for differential pair?

Best,

Dalik

Brian TIDAL · ‎2023-10-10

Hi,

I would recommend to use STM32CubeMX that will help you to define your clock tree for your MCU.

The STM32F030K6T6 is having a LQFP32 package where the OSC32-IN and OSC32-OUT pins are not present (thus it is not possible to use a Low Speed External 32.768 kHz crystal).

Depending on your application needs, you can clock your system either from the High Speed Internal (HSI) 8 MHz RC clock or from an High Speed External (HSE) 4-32 crystal (providing a better clock accuracy but of course with an impact on your BOM). See RM0360 Reference Manual §7 for the description of the various clock.

Rgds

BT

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Brian TIDAL · ‎2023-10-02

Hi,

the ST25R95 is a slave device controlled by an host. Can you share more information on your use case?
VPS_TX is limited to 5V. What do you mean by 10V on TX1 and TX2?

Rgds

BT

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Dalik · ‎2023-10-10

1. I use it for charger power only, and I want to know if it can program directly to ST25R95 by not using MCU (host).

best

Dalik

Brian TIDAL · ‎2023-10-10

Hi,

as explained, the ST25R95 is a slave device. It needs to be driven from SPI.

Rgds

BT

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Dalik · ‎2023-10-10

Hi

I have developed a product of a USB type-C charger for a smart card. For the NFC reader, I have used ST25R3912 as a slave with an external clock of 27.12 MHz and for the host, I have selected STM32F030K6T6.

1. Is it possible to use an external clock of 32.768 kHz for the host?

2. Can you recommend the external clock for the host?

Best

Dalik

Brian TIDAL · ‎2023-10-10

Hi,

I would recommend to use STM32CubeMX that will help you to define your clock tree for your MCU.

The STM32F030K6T6 is having a LQFP32 package where the OSC32-IN and OSC32-OUT pins are not present (thus it is not possible to use a Low Speed External 32.768 kHz crystal).

Depending on your application needs, you can clock your system either from the High Speed Internal (HSI) 8 MHz RC clock or from an High Speed External (HSE) 4-32 crystal (providing a better clock accuracy but of course with an impact on your BOM). See RM0360 Reference Manual §7 for the description of the various clock.

Rgds

BT

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Dalik · ‎2023-10-17

Hi,

ST25R3912 has an MCU_CLK pin, but my product uses charger power only and I need to know about the Power level from the card.

1. Does This pin need to be used?

Best,

Dalik

Brian TIDAL · ‎2023-10-17

Hi,

The MCU_CLK pin may be use as clock source for the external MCU. The main use case is when using the transparent mode which is likely not your case (see https://community.st.com/t5/st25-nfc-rfid-tags-and-readers/mcu-clk-as-microcontroller-clock-source/td-p/232591 and other related posts. Se also the § Pin MCU_CLK in chapter 1.2.11 in ST25R3912 datasheet).

So I believe this pin is not needed in your application.

Rgds

BT

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Dalik · ‎2023-10-17

Hi,

Low price is first priority for developing my product, for a slave I have selected ST25R3912.

1. Can you recommend ST chip as a host controller for a good price for the product?

2. What is technical to switch the power mode output of the NFC module between 3V mode and 5V mode?
Best,

Dalik.

Brian TIDAL · ‎2023-10-18

Hi,

I would suggest to use the MCU/MPU selector from STM32CubeMX. This will help you to find the adequate MCU for your project based on several filter such price, Flash size (make sure to estimate your flash need), RAM size (same comment), IPs (SPI), number of IOs, etc.
see § 1.2.10 in the ST25R3912 Datasheet: "The supply mode is set by writing bit
sup3 V in the IO configuration register 2. Default setting is 5 V, hence this bit has to be set to
one after power-up in case of 3.3 V supply."

Rgds

BT

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