AFE58JD18: Pre-configuration behavior?

Gregory Duperon

Part Number: AFE58JD18

It seems that if the AFE is powered on--but not yet configured--and left in that state for a while, it will get hot. I've found that if I assert the PDN_GLOBAL pin, the unit will not get hot.

Should I be applying a pull-up resistor on this, or some other pin (such as holding the device in reset) to prevent the device from getting hot if it is powered on but not configured?

Thanks.

over 4 years ago

0 Xiaochen (Sean)Xu over 4 years ago

TI__Expert 6040 points

Greg,

when AFE is powered up and its AMP and ADC are running directly. in this case, the total power consumption is about 140mW/CH if ADC CLK is 65MSPS.

So 16Ch is about 2.2W. the termperature rise is about 40 to 50C. that is why it is warm or hot. power down pin will shut down most blocks, so temp drops.

this is expected beheavior . Thanks!

0 Matthew Coolidge over 4 years ago in reply to Xiaochen (Sean)Xu

Prodigy 30 points

Hi,

Is it ok to use a pull-up resistor on the power down pin, or will that have adverse effects?

Thanks,
Matthew

0 Xiaochen (Sean)Xu over 4 years ago in reply to Matthew Coolidge

TI__Expert 6040 points

it is OK to have a pull up resistor. device internally has a 16K ohm pull down resistor. So you will need to have a smaller pull up resistor to form a votlage divider and meet the VIH of 1.4V for power down pins.

Thanks!

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AFE58JD18: Pre-configuration behavior?