where the output/input impedances can be found or can they be calculated?

[HABIJ.1]

Hello,

I am searching for the input/output impedances for my STM32L476RG microcontroller and I can't find any information in the microcontroller datasheet or else where on the web.

Are those values given in any documentation? If not, can they be calculated?

Regards,

[Bouraoui Chemli]

Hello @Honoré Julien ABIJURU​ 

Can you please provide more details?

Also, which mode are you interested in, input mode or output mode?

For input mode, the input mode impedance is CIO = 5 pF from Table 70. I/O static characteristics of STM32L476 datasheet.

Bouraoui

[HABIJ.1]

Hello Bouraoui,

Thanks for your reply.

I am interested by the impedance values of the maximum loads that can be connected to the STM32L476RG.

As in my application, the STM32L476 microcontroller will be in transmitter and receiver modes for SPI communication, I am interested in both the input and output impedance maximum values.

For the 5pF value, I think it is the capacitance presented by a GPIO pin on the board.

Regards

[Bouraoui Chemli · Accepted solution]

Hello @Honoré Julien ABIJURU​ 

You can refer to STM32L4 IBIS models for signal integrity applications.

Also, this application note AN4803 "High-speed SI simulations using IBIS and board-level simulations using HyperLynx® SI on STM32 MCUs and MPUs" can help for the signal integrity simulation.

Bouraoui

[HABIJ.1]

Thanks for the resources, I'm gonna try that!

Regards