LM5170-Q1: Number of phase limitation and how the interleaving currents are balanced?

Hi Yada,

What is the power requirement for this project? How many phases does the customer plan on using?

1) Number of phase limitation, in datasheet, Table1, max number of phases is specified only "2xN", however, there may be realistic limitation, so what the realistic max_number of phase? if there is, by what this will be limited?

It is true that 2xN number of phase can be used since this LM5170 acts a current source. The only practical limitation is if the customer wants all the phase to operate interleaved using the internal oscillator and the SYNCOUT/SYNCIN pins. Up to 4 phases can achieve interleaved operation without the use of an external clock. Section 7.4.1.3 of the datasheet explains this in more detail.

Other then that there are no real limitations on the number of phases.

2) Like datasheet application, dual phase case, interleaving current are controlled by CH1 or CH2. Interleaving current shall be balanced between CH1 and CH2. if the current will be out of balance, increasing CH1 more while decreasing CH2. What happen? 

Interleaved operation just refers to how each phase switches in relation to other phase. The current between each phase will still be balanced. 

Thanks,

Garrett