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Multiple AD7190 on same SPI

while using single AD7190 i am able to communicate with IC.

I want to use multiple AD7190 ADC's on same SPI.

but due to same DOUT/RDY pin i am not able to understand how to use multiple ADC on same SPI, can you please guide me ?

  • Hi,

    Could you please share the schematic of the connections on Multiple AD7190 on same SPI?

    I believe you havent used pull up resistor on the SPI pins.

    Thanks

    Vikas J

  • Can I use multiple AD7190 on same SPI ?

    how can i understand RDY pin status ?

    If i want to read ADC1 and make CS pin low of ADC1 and CS pin is high of ADC2  , what will be the status of ADC2's RDY pin, will that make any difference in ADC1 ready staus?

  • Hi, 

    When /CS of the specific device is high the DRDY pin will be in high Z mode and the part will not be able to monitor conversion.

    So, for a system that uses multiple ADCs, the interface can be simplified by synching the devices. For example, configure one ADC as the master and configure the remaining ADCs as slaves. The clock from the master device can then be used as the clock for all parts. That is 1 ADC MCLK output, then used this as an input to the other ADCs and it will only have approximately 1MCLK difference. Then by writing a common command to all devices such as selecting continuous conversion mode will reset all ADCs. The customer would then only need to monitor the DRDY signal from the master device. When the master DRDY goes low, read its conversion. At this point, the other ADCs will also have conversions available so their DRDY signals do not need to be monitored. This architecture would simplify the connections between the ADCs and the uC. With this architecture, it is important that all conversions from the ADCs are read back before the next conversion from the master ADC is ready this ensures that all conversions from ADCs are read (ensures no conversions are missed). 

    Thanks,

    Jellenie