Hi,
I saw from SNVA695: . It is required to drive the RT/CLK pin of all devices with an external clock to ensure they switch at the same frequency. The clock signal must be present before the devices are turned on. The LMZ31710 produces a SYNC_OUT signal which is a 180° out-of-phase clock that can be driven to another device's RT/CLK pin to synchronize 180° out of phase.
I am puzzled that the external clock is required or optional. If it is a must, i have to connect a external oscillator. I think it's not reasonable for DCDC design. Can the master still use RT to set the switching frequency, then SYNC_OUT to next device?
I don't see any mention about this option in SNVA695. If it's OK, this app note should be revised.
Thanks
Peter
