Other Parts Discussed in Thread: CSD
Hi, There,
We are using TPS53667 for I/P 12 VDC to O/P 0.85 VDC @144 Amps design with 6 phase in operation. On my first prototype for this design TPS 53667 with 6 nos of CSD 95490 for 6 phase, stops working immediately at power on. Type of behaviour it shows is "it is experiencing O/P OV". As its controller try to restart after Hiccup delay of 22 mSec, 3 times.
We have used above chip set combination on other design and it has worked well couple of design for 5 phase designs. Also we have web benched designed and checked all component and its value very well on this board so we are not suspecting on layout or design values at this point of time. But we still seek your quick advise on the same.
As Internal regulator in above condition are showing healthy voltages, we tried to read PMBUS register on PMBUS. In PMBUS Register also we observed device has logged Over voltage fault and not OC, UV or Temp faults.
So when we read PMBUS Register, following were results.
- Register 78H Value 61H.
- Register 7BH Value 08H.
- Register 80H Value 30H.
We are a bit surprised to receive these values.
-
In register 78H we should get value - 60H for OVP, Why are we getting 61H. What does it mean to have other fault in this chip?
-
In register 7BH we should get value - 00H, Why are we getting 08H. What does it mean?
-
In register 80H we should get value - 00H, Why are we getting 30H. What does it mean?
We repeated the above fault condition so many times and also read registers so many times all time it gives same above value. Also value for lot of other registers are coming up correct as per datasheet of the TPS53667.
Can someone, quickly guide us what this register value means and what type of next steps we should take to quickly move forward.
Your quick response will be well appreciated.
Regards,
Suhant.