ZSC31015Exx with piezoresistive bridge sensor, oscillations

Question

Dear, 
 
 good day! 
 we use ZSC31015 as piezoresistive bridge sensor signal conditioning to assemble pressure sensor. Everything runs smoothly. We meet strange thing that when we put the pressure sensor into use, if we add 100nF to 470nF capacitor at sensor output PIN to the ground to smooth the signal, about 2% products would occur Oscillation in output. The frequency is 42.117kHz and amptitude is 400 mVpp. if we remove the capactor, the output signal is fine.

why this phenomenon happen? could you list some factors caused this issue? 
 Many thanks and Best Regards, 
 Jarvis

Jarvis · Accepted Answer

Dear IK, 
 Many thanks for your support. 
 Our customer has used morre than 10k pcs. The failure rate is about 2%. 
 I guess the output short-circuit protection take action. I checked the datahseet, the short current limitation is from 3mA to 40mA. During the output charges the capacitor, the current is more than 3 mA and a few ZSC31015 is just in the low end. 
 Best Regards, 
 Jarvis

IK_Renesas · Answer

Hello Jarvis, 
 Thanks for reaching out Renesas Engineering Community. 
 Would it be possible to share with us your schematics? I assume that you are not using the EVK. 
 The picture from the oscilloscope you sent I assume is when the capacitor is not connected is that correct? 
 Please let me share with you the resistor and capacitor limits depending on the programmed output mode:

Best Regards, 
 IK_Renesas