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AD5522 MEASOUT Voltage mismatch from actual MEASSVH voltage.

Hi

We use ADI's AD5522 Evaluation Board and GUI and measure MEASOUT in FOH0 shorted DUTGND.

If  FOH0 DAC sweep from 2V to 18V , MEASOUT(from AGND) increase from DAC=7V and MEASOUT is up to 8.2V in linear.(MEASOUT mean (MEASOUT_result×5-1.25))

Actual MEASSVE voltage is about 0V . 

The Result image is below.

Which condition is bad?

Are there any improvement?

Condition 

AVDD 25V
AVSS -5V
FOH0 Connect to DUTGND(pin8)
Mode FV
MEASOUT Voltage ×0.2
DUTGND DUTGND(not indivisual)
GAIN

GAIN1=1

GAIN0=0

digital input

System register:003FE4A0

PMU retister:0F21B300

This format is GUI's write column.

Jumper

LK3 ON
LK9 ON
LK2 A
LK4 B
LK5 A
LK15 B

AD5522 foot room in datasheet

We have below information. 

But foot room is enough. 

https://ez.analog.com/data_converters/precision_dacs/w/documents/3484/ad5522-power-supply-rails

Best regards 

Thank you very much.

Top Replies

  • Hi ,

    Is DUTGND connected to AGND as well? If yes, FOH0 and DUTGND should not be shorted together as it will draw large amount of current from the force amplifier that will trigger your current clamp…

  • Hi ,

    Is DUTGND connected to AGND as well? If yes, FOH0 and DUTGND should not be shorted together as it will draw large amount of current from the force amplifier that will trigger your current clamp. This might also damaged the part eventually. Please disconnect the DUTGND pin from FOH0 pin and connect the DUTGND pin to AGND instead. This is the default configuration of the AD5522. Lastly, can you provide some scopeshots on the output sweep voltage or data from the test so we can better help you in your inquiry?

    We can take this offline if you want. Just email me at danilojames.marciano@analog.com.

    Best Regards,
    DJ