I am using PMIC MC34708 in one of the iMx537 design. The PMIC chip is not coming up.
I am giving 3.3V as the BP input. The reference voltages are coming correctly.
Any help in this regard is greatly appreciated. Thanks in advance.
I have 2 suggestions about your design :
(1) BP Voltage.
3.3V is too low. BP pin is for single battery input , It's normal input voltage should be 3.5~4.2V.
if MC34708 doesn't work, please measure WDI pin to check if this pin is High . If the level is low, MC34708 doesn't work.
Thanks for your reply. The said design is part of the bigger system and this is a module in it and has input power that is 3.3V only. I do not have any option to increase the voltage. Is there any other alternative chip available.
WDI pin is showing low only.
I have isolated all the loads from the chip completely to check if it was overloading. Now if I give 3.6V from an external source it tries to come up and goes down immediately.
Is the load necessary for the PMIC to come up.
with best regards,
The issue is not related to load . mc34708 is designed for single li-cell battery with standard 3.7V input, So for a single li-cell battery, it is MAX voltage is 4.2V, if you use 3.3V to be input of BATT pin on mc34708, It is really too low. We ofter use a 5v-->3.8v DC-DC power IC to be input of MC34708, this DC-DC is just like a signle li-cell battery !
Thanks for your reply. The chip is coming up now. I pulled the WDI to high. All the voltages are coming up even at 3.3V. Thanks for your support.
Good Job !
I still suggest you should notice the value of VCC_BP, 3.3V input is courageous design, You are a brave guy ! ,Hope you can use standard Voltage (3.7/3.8V) to be BATT input of MC34708 in other designs.
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