We are using MSP430FR5738IYQDT as a 32.7668kHz oscillator for testing our designed oscillators.
But short failure between DCC(ACC) and DSS(ASS) has occurred.
We saw the same failure 3 times.
The pin configurations of MSP430 are described below.
- P2.0(ACLK) : external frequency counter for frequency measurements
- PJ.4(XIN) : our oscillator under test
- PJ.5(XOUT) : our oscillator under test
- DVCC and AVCC : Both are connected to DC3.3V on our PCB (not separated)
- DVSS and AVSS : Both are connected to GND on our PCB (not separated)
- Vcore : Connected to DVSS via a 470nF capacitor.
- TEST/RST : Connected to our PC for controlling
-All other pins : Not connected (floating)
And we are using a regulated power supply for DC3.3V.
So our questions are,
1. What is the root cause of short failure between VCC and VSS?
2. Can we identify which part of MSP430 is broken?
3. Can you perform failure analysis if we send you actual failure samples?
For example, can you identify from which pin enters if overvoltage(such as surge voltage) is the cause?