LM5119: 4 phase operation with two LM5119s

Ryuji-san,

Below is the informatoin on that post. What's Vout in your design?


LM5119 is not designed for 4-phase operation originally, but is capable of operating in 4-phase with some limitations.

1. A COMP in master channel and three COMP pins in slave channel & slave IC should be tied together.
2. Three FB pins in slave channel should be pulled up to local VCC
3. To synchronize two ICs, 90 degree phase-shifted clocks should be applied.
4. RES should be tied to VCC. This means hiccup mode operation should be disabled.
5. TSD / VCCuv / UVshutdown events on master side IC will shut down all four channels eventually, by pulling down the shared COMP node.
6. TSD / VCCuv / UVshutdown events on slave side IC will shut down the IC under fault.
7. All UVLO pins should be tied together. This means UVLO hysteresis current will be 4x20uA in 4-phase.
8. Css on master channel is recommended to be much larger value than the other Css capacitors.