ADS8638: The device becoming very hot once given power supply

Yuting Chen

Part Number: ADS8638

Hi:

I use ADS8638 in my design. I fined that when I supply the HVDD=15V and HVSS=-15V,the device becoming very hot in a short time,while there is no problem if I supply AVDD=3.3V and DVDD=3.3V in the same time . What's wrong with the device?

Here is my schematic：

Thanks!

Ingrid

over 8 years ago

0 Dale Li over 8 years ago

TI__Mastermind 46595 points

Hello Yuting,

There is a mistake in your schematic, Pin 23 (REFGND) should be connected to Ground(GND), please refer to Figure 95 in ADS8638's datasheet. Please correct it and check again. Thanks.

Best regards

Dale Li

0 Yuting Chen over 8 years ago in reply to Dale Li

Prodigy 40 points

Thank you for your help!
I have connected REFGND to GND and try again,but the problem still exists.

0 Dale Li over 8 years ago in reply to Yuting Chen

TI__Mastermind 46595 points

Hello Yuting,

Can you please check if your input signal is available before power up HVDD and HVSS? another experiment test you can do is, power up AVDD firstly then DVDD then HVDD and HVSS, actually there is no special power up sequence is required, but please check this, thanks.

Regards

Dale Li

0 Yuting Chen over 8 years ago in reply to Dale Li

Prodigy 40 points

Hello Dale,
Thanks for reply.
There is no this issue if power up AVDD and DVDD before HVDD and HVSS. Maybe it's a normal occurrence if power up HVDD and HVSS first...
Yuting Chen

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ADS8638: The device becoming very hot once given power supply