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AD7606-4 operation problem or damaged IC

Question asked by Chris_Analog_Dev on Dec 18, 2016
Latest reply on Dec 23, 2016 by jcolao

I try to conect AD7606-4 with STM32. I would like to get something validate values from this on low Fsample.

First i do a mistake on PCB conention with Vdrive and REF SELECT pin. I conected REF SELECT to Avcc (5V), second mistake was very thin trace to Vdrive. I thougt that this is a output stage reference voltage pin (but it is a output stage supply pin). When i try to start with this configuration the IC give a 100 - 200mA current. I very fast disconect the device from supply. In this case on Vdrive pin was voltage 4,3V and conection to 3,3V cause around 200mA curent consumption. I was very careful and i don't alow to high temperature of AD7606-4. It was max 30C. Now i improved the mistakes in conection. The IC give 7 mA on STANDBY and 17,5mA on NORMAL OPERATION. I think that current is OK. My conections:

 

OS0-GND

OS1-GND

OS2-GND

Vdrive 3,3V

REF SELECT - Vdrive - INTERNAL

STDBY - Vdrive

RANGE - GND

PAR/SERIAL - Vdrive - SERIAL

 

I would to take data from DoutA.

I don't know which signals must be pulled down/up or conected by serial resistor.

The SCLK freq is some kHz.

 

The IC response with BUSY signal and FIRSTDATA but on FIRSTDATA pin is to many pulses.(8 instead of 1)

Secondly on DoutA i receive 0 value or random value on all channels same. I strobe every 16 sclk pulses by CS.

When I switch ON the device the value is usualy 0 to time when i touch some pin by oscilloscope sonde or by toe.

Then ADC return some values but not corect. Secondly the BUSY pin pulse width isn't constant. Sometimes the width is 5uS sometimes 70uS. I don't know cause of this behaviour.

Maybe the problem is in software or i damaged the ADC IC.

I added the screenshots.

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