Hi, I am trying to use 4 x tps40180 parallel for high current application (like datasheet page 22 ), but I have problem about the PSEL setting.
Condition 1:
Master PSEL: OPEN=8 phase CLKIO
Slave1 PSEL: 14.7Kohm=90 degree
Slave2 PSEL: 47Kohm=180 degree
Slave3 PSEL: 95.3Kohm=270 degree
Vin=12V, Vout=5V, Iout=60A
I found the switching node waveform of MASTER and Slave 2 have jitter phenomenon when output load between 20~30A. When the output current higher then 30A, the jitter phenomenon was disappear until to 50A.
Condition 2: (exchange Slave 1 PSEL for Slave 2 PSEL)
Master PSEL: OPEN=8 phase CLKIO
Slave1 PSEL: 47Kohm=180 degree
Slave2 PSEL: 14.7Kohm=90 degree
Slave3 PSEL: 95.3Kohm=270 degree
There is no jitter phenomenon and converter is stable during 0~60A. If you change others angle either Slave 1 or Slave 2 or slave 3, system become unstable.
Does anyone can help to explain the design rule of PSEL setting for 4 x TPS40180 parallel? or share the design experience?
Thanks
Aston