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Associate II
January 29, 2026
Solved

ISM330DHCX and IIS2MDC connection mode 2 and pullups

  • January 29, 2026
  • 1 reply
  • 148 views

 

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

nachus001_1-1769659288046.png

 

Thanks in advance

Ignacio

Best answer by Federica Bossi

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 

1 reply

Federica Bossi
Federica BossiBest answer
Technical Moderator
February 2, 2026

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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