Power supply of LSM303AH

[rimbaud]

Hello,

I am using steval-miki173v1 for testing LSM303AH.

I have supplied this one by mistakes with 3.3v. And its working well, but not good idea sure.

I have made the same mistakes on my customized PCB, supplied LSM303AH directly with 3.3 and this is does not work. I have remade the same schematic as recommended in the data sheet.

Do i have to seen working well like on eval kit with 3.3v ?

I am asking another question for my self, if there are other mistakes before correcting this one.

Thank you,

[Eleon BORLINI]

hi @rimbaud​ , 3.3V is out of datasheet values for this product (also out of absolute maximum ratings), so the device might not work.

However, which is the VddIO value in your pcb? Are you communicating with the LSM303AH device via SPI (no pull-up needed) or I2C (pull-up neede at Vdd)? You should also check if yor master SPI / I2C works well when Vdd is 3.3V. Regards

[rimbaud]

Hi @Eleon BORLINI​ 

At first i have worked with steval-mki173v1 with my MCU devKit, i have supplied steval with 3.3v.

My custom PCB made VDD and VDD_ID connected together supplied with 1.8 v throw regulator which transforme 3.3v to 1.8v.

But my MCU is working with 3.3 v, when i have seen the I2C communication not working i have made some adaptation to make VDD and VDD_IO supplied with 3.3 volt and still i have the same problem.

Yes i have made pull-up resistor fir SCL and SDA.

My I2C Master is working with 3.3 v.

Please find attached schematic.

regards