AD5522 High-Z FOHx Current

Hi, baggio. 

Thanks for your patience. I just got back from vacation so I am just catching up.

Based off the commands you sent, it looks like you are not selecting your PMU channels.

Please see snip below:

In your commands, these bits are set to 0000, which means you are writing into the System Control Register and not to the PPMU register.

Please let me know if the issue persists after correcting your commands.

Best regards,
Mac

Hi, MacManato.

Thank you for answering. I'd like to try that suggestion.

We will post the results here as soon as they are available.

Best Regards.

Hi, MacManato.

Thank you for answering. I'd like to try that suggestion.

We will post the results here as soon as they are available.

Best Regards.

Hi, MacManato.

I tried the following setting. However, the problem was not resolved.

　1, First, I set 0x013A A080.

   　(High-Z FOHx current / Disable the always on mode for the external current range buffer1 .)

　2, AVSS Change -15V → -5V (1st pulse)

　3, AVDD Change 16V → 27V (2nd pulse)

　4, Wait  

　5, AVDD Change 27V → 16V (3rd pulse)

　6, AVSS Change-5V→  -15V  (4th pulse)

Here is the waveform from that time.

Best Regards.

Hi, baggio. 

May I ask what specific pin you are measuring from, including the channel number?

Best regards,
Mac

Hi, MacManato.

I'm checking the details, so please wait a moment.

Best Regards.

Hi, MacManato.

I apologize for the delay, but I have confirmed the information.

I have noted that the set value and measurement point differ, so I am providing the details again. 

The settings are as follows.　

　1, First, I set 0x011A_A080.
　　(High-Z FOHx current / Disable the always on mode for the external current range buffer1 .)
　2, AVSS Change -15V → -5V (1st pulse)
　3, AVDD Change 11V → 23V (2nd pulse)
　4, Wait
　5, AVDD Change 23V → 11V (3rd pulse)
　6, AVSS Change-5V→ -15V (4th pulse)
　7, End

The measurement point is FOH0 as shown in the figure below.

The measurement waveform at this time is shown in the figure below.F

We believe the AD5522 output does not affect the measurement point.

However, in reality, the measured voltage fluctuates when the power supply voltage fluctuates.

Are there any points missing from the settings?

Best Regrds.

Hi, baggio. 

I am seeing some violation of the values of the supplies. Please note that the difference between AVDD and AVSS must be between 20V and 33V at all times.

During your transitions, there are times when the difference between the supplies fall below 20V. For example, when you change AVSS from -15V to -5V while AVDD is still set to 11V, the difference is only 16V.

Best regards,
Mac

Hi, MacManato.

Thank you for your reply. I would like to request an adjustment to the power supply voltage.

However, based on the waveform, issues also occur during voltage fluctuations, so I believe the symptoms will persist even if the power supply voltage is changed. What do you think?

Best Regrds.

Hi, baggio. 

We need to see first if it still happens on your end after changing supplies that don't violate the specs sheet. In case there's a need to do bench work, please note that the earliest date available will be on Jan 7th as the team will be out of office starting today for the holidays.

Also, may I ask why there's a need to change supplies? What is the application?

Best regards,
Mac

Hi, MacManato.

I will review the details and reply here once I have the results.

Thank you for your support this year. Have a wonderful Christmas holiday.

Best Regrds.