MPQ8645P/MP8796B feedback on multi-phase operation

Hi,
I have a question regarding multi-phase operation: On the MPQ8645P and MP8796B datasheets It is unclear how design the feedback network. In particular on MPQ8645P DS page2 the two devices are usign their own internal feedback but on page 17 two of them are using an external feedback each and the last one is using the interal one. On MP8796B DS page18 All devices are usint the internal one, BUT, the evaluation board EVREF0105A, where 6 MP8796B are present in an “up-to” 6 phase operation configuration, all of them are sharing the same feedback network. This configuration is unclear.
I am looking for more information about how design the feedback network in a MULTI-PHASE OPERATION, since datasheets don’t provide enough information.
How can those devices have different feedback networks (internal or external)? since all of them are subject to different tolerances?

Thanks in advance
Antonio

Hello Antonio,

You can set up both an internal and external feedback voltage divider. For the internal voltage divider, it has a range of 162mV to 672mV.

Please see page 21, 22, and 23 for more information. There is a step by step process how to get the appropriate output voltage depending on the divider selected.

Regards,
Vinh Tran

Dear Vinh,
I’ve seen those pages but in short my question is:
In multi-phase operation, do slave’s pins VOSNS+/- have to be connect directly to master’s pins VOSNS+/- (after an common external feedback)? or do any slave devices have to be connect to Vout through to a own external feedback?

Thanks in advance
Antonio

Dear @vinh.tran Could you provide an answer? Thanks

Hello a.nicolosi,

We have found that only connecting the master VOSNS+/- is enough. Due to the longer traces required to connect the slave devices to the load causes inaccuracies.

Regards,
Vinh Tran