ISM330DHCX and IIS2MDC connection mode 2 and pullups

nachus001 · ‎2026-01-28

Dear sirs.

I'm connecting an ISM330DHCX with an IIS2MDC and I need to know if the connections scheme is okay to operate in MODE 2

Then I need to know if pullups are needed for i2c bus coming from SCx and SDx, and if pulldowns are required for INT lines as in the provided schematic.

I'm based on the ISM330DHCX and IIS2MDC datasheets and X-NUCLEO-IKS02A1 board manual

The routing jumpers are there just in case we need to route one magnetometer to tha main I2C bus

Thanks in advance

Ignacio

Federica Bossi · ‎2026-02-02

Hi @nachus001 ,

The schematic is ok. The external pullup resistors must be used because the internal resistors values are very high and they're used only to avoid floating pin value. For same reason it is better to use the pull down resistor on INT (DRDY) pin

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Federica Bossi · ‎2026-02-02

Hi @nachus001 ,

The schematic is ok. The external pullup resistors must be used because the internal resistors values are very high and they're used only to avoid floating pin value. For same reason it is better to use the pull down resistor on INT (DRDY) pin

In order 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.