BMA456 de-coupling capacitors

[osau]

Hi,

We're looking at using the BMA456 in our design, which is fairly space constrained.

VDD and VDDIO will in our case be the same. Do you need both decoupling capacitors, or is one 100n enough? Or can we use one 200n?

Best regards,

[BSTRobin · Accepted solution]

Hi osau,

The 100nF capacitor cannot be changed to 200nF capacitor, because the function of adding decoupling capacitor is to filter the noise at a specific frequency. Changing the capacitance will change the filtering frequency.

Our best suggestion is to connect 100nF capacitors near VDD and VDDIO pins respectively. If you really need to save cost, you can use one capacitor, but you must ensure that the capacitor is close to the VDD or VDDIO pin on the PCB layout.