The ADS7861 wery easy to damaged How to protect?
I use ADS7861 to decode SIN/CON encoder (with PMSM motor driver 15KW power).The ADS7861 work on mode #3Before enable PWM Signal (IGBT control signal) The ADS7861 work normallybut after enable PWM Signal The ADS7861 damaged
Hi Chin-Win Lin,
Can you describe for us how you have the ADS7861 connected to your encoder? Would it be possible for you to share a schematic? I suspect when you enabled the 15KW power, there may have been a differential voltage developed across the AGND/DGND boundaries which exceeded the +/-300mv limits or perhaps caused spikes that were above/below the rails. Any detail you can supply which may help us help you locate the potential cause of damage would be greatly appreciated.
Regards,
Tom
Hi Tom : Yes I think you are right. when turn on the PWM(Big power ) I measure The voltage of AVCC/AGND ,The grounding bounce generate, the Voltage up to 1 ~~1.5 Volt
How to eliminate grouning bounce ?
Regards
Hi Chin-Win,
Ground bounce can usually be attributed to layout and component selection. Having local bulk capacitance can help relieve issues between the supplies and ground - the ADS7861 has two supply pins and two ground pins. Pins 1 and 12 should tie directly to the same ground point (preferably a ground plane). Pins 13 and 24 should also be tied to the same +5V rail. If you can send along your schematic and/or layout, we'd be happy to review them for you.