AnsweredAssumed Answered

MX535 and MC34708 Startup

Question asked by Geff Fischer on Dec 6, 2012
Latest reply on Jan 17, 2013 by Geff Fischer
Branched to a new discussion

I have a custom board with multiple iMX535's and MC34708 PMICs. Each processor is independent, there is no connection between them. (The design is very similar to the QSB.) One of the processor starts up just fine and enters serial boot mode as it is strapped to do. The other processor stays in reset. I think the MC34708 PMIC is the USER OFF state, RESETB is low, but RESETBMCU is high. All of the output rails are at the correct voltages. I've tried forcing different turn on events as described in section 7.5.3.4 of the datasheet, but RESETB stays low. There is nothing else driving the RESETB signal.

 

What condition(s) on the inputs to the MC34708 will cause it to assert RESETB low?

Is there is a simpler way to force a turn on event and put the MC34708 in ON mode?

Outcomes