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STUSB1602 pins connection

Associate II

Hi there,

I am seeking some guidance regarding the connection of the STUSB1602 to the STM32L031G6U6 microcontroller for a low-power application with a small footprint.

Currently, I have already connected the STUSB1602 to the microcontroller using the I2C interface. However, I am uncertain about the compatibility of the MCU, also wether do I need to connect the SSI pin interface. Given that I am relatively new to designing circuits, I am seeking clarification and advice on this matter.

Could you please provide insights into how I can properly connect the STUSB1602 to the STM32L031G6U6 microcontroller using the SSI pin interface? Additionally, I would appreciate any recommendations or resources that could assist me in ensuring compatibility and optimal performance.


I have also attach the schematic I'm talking about

Thank you very much for your time and assistance.

ST Employee

Hello @xKrerahpus 

You can refer to Application note - AN5164 - STEVAL-USBPD45C 45 W USB Type-C™ Power Delivery adapter 

Figure 34. STEVAL-USBPD45I digital control board schematics

Also check User manual - UM2404 - STEVAL-USBPD45C 45 W USB Type-C™ Power Delivery adapter reference design Figure 13. STEVAL-USBPD45I

About your second question, you can interface STM32L0 though i2C communication and SPI :

  1. The I²C bus is used by the MCU to configure and control the device status. As the STUSB1602A
    has a customizable start-up profile that can be modified by accessing its integrated flash via the I2C.
  2. The SPI peripheral is reserved for Power Delivery communication. As the STUSB1602A embeds a BMC transceiver, every BMC encoded or decoded message exchanged between the MCU and the device is carried on the SPI bus.


To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.

ST Employee


STUSB1602 needs SPI interface, on top on I2C interface.
On schematic you shared, it seems that SPI is not connected. 
As your application is a power bank, DRP profile will be needed. 
We have a package based on stm32L073RZ, if STM32L0 is your final choice.

Best regards


Hi, thanks for your help.

So refering to AN5164 Fig. 34 as you have mentioned, is it possible to add an I2C display on to the same I2C bus?
Also, is it possible to change the MCU to STM32L051K8 with the exactly same pin connection?

Hi, Thanks for your reply.

What is the package you have mentioned, and will it work properly on STM32L051K8 if it's based on Stm32L073RZ?
Also, in GPIO configuration menu, do I have to set the I2C channel to I2C or SMBus Alert mode?

I'm genuinely excited to learn from your wealth of knowledge. Thank you in advance for sharing it with me.



To answer properly to your questions, may I know which kind of application you are targeting ?

Is it single USB C port ?

Is it source only (i.e provides vbus power) or sink  only (i.e receive power) or dual role ? Is the application has USB data ?

Best regards



So the project I'm working on is something like a super simple but very efficient powerbank which has a single USB-C with DRP, no data connection other than the CC pin for PD negotiation. Has an 32x128 I2C OLED display and maybe shake to wake feature if it is possible.

I hope my response provides clarity and assists you in understanding how you can help me.


It seems possible to use stm32f051k8 with your application
I'll contact you in private message
Best regards



Feel free to contact me via private message whenever you're ready to discuss further details or if you have any questions. I'll be here and ready to assist whenever you need.

Best regards