Not getting DRDY signal.

Hi PritiGaikwad ,

You should see the first DRDY upon reset after typically 100 uS. Can you share your schematic and register settings so we could further check?

Thanks,
Janine

Hi,

Now i am getting DRDY signal after 100usec. But the DRDY signal stays HIgh only for 100 nsec. As the DRDY high period is very low. I am unable to detect the DRDY state change at microcontroller side. 

and register and thier values are :

0x6C --> 0x00

0x1D --> 0x03

0x1D --> 0x02

0x14 --> 0x01

0x15 --> 0x33

0x18 --> 0x90

0x19 --> 0x01

Iam using SPI interface in continuous mode. MCLK is 16.34 Mhz. 

want to have ADC data 128kbps.

but after setting countinuous conversion mode iam not getting data.

I had the same problem with short DRDY. I have to use a monoflop to make the DRDY last longer for the µC.

Hi PritiGaikwad - Are you using interrupts to detect the falling edge of the data ready pulse?

Thank you,

Janani

No. Iam not using interrupt But iam polling DRDY pin at microcontroller.

and now i have kept the MCLK 1MHz and iam getting 1usec DRDY high pulse.

But even after configuring all adc register not getting ADC data. 

Hi.thanks for replying.

As now iam able to sense the DRDY changes at microcontroller  but iam getting 0x00 as ADC data o/p.

I have also checked the SPI and ADC DIAG and STAT register. and there is no error flag raised.

Hi PritiGaikwad  could you please share a scope capture of the SPI signals with the DRDY all in one frame ?

Thank you,

Janani

DOUT and DRDY signal

Dout and SCLK

also set the register values and read the same values.

Power and control (0x15) --> 0x33

conversion source (0x18) --> 0x90

Digital filter            (0x19) --> 0x82

still getting zero as o/p data.

Hi PritiGaikwad ,

Thanks for sharing this. You can read the register values in DOUT but not the conversion results, is that right?
Can you please share your schematic and other register values?

Thanks,
Janine

Hi,

Yup iam not able to read the conversion results.

For schematic we have followed the AD7768 evaluation board schematic and same register values.