Other Parts Discussed in Thread: TPS60403
we are using the ADS1298 in an ecg-application.
DVCC: 3.3V
AVCC: +2,5V
AVSS: -2,5V
We have the situation that during test we lose some ic because of damage.
The effect after this happened is:
- Input-Impedance of Din is only 500R
- in some cases the supply-current (normal 75mA) rise to 150…250mA
First thing we found was a peak on DVDD off 2ms to 4,2V during Power-Up. We put an 3.3V LDO in line to eliminate this peak.
A other thing that I can see with the oscilloscope is a short peak at AVSS to 0,8V ( it is coming out of the ADS1298).
So we put an Shottky-Diode in and we could limit it to 400mV.
Do you have an idea?