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LMC6492: Need a current pumping /boosting/amplifier for battery charger

Part Number: LMC6492

Hello Sir,

My application need a battery management charger IC.
Take a look the design layout,



1. A micro USB connector from smart phone to PC or power adapter will be use.
2. From this USB connector VBUS will be supply power to my external system through the battery charging IC.
3. This IC will manage the 5V , 2A power from adapter but, in quick charging mode, 9V, 2A power should be block by the management IC.

If you look on the diagram you would see, the current path is divided in 2 ways!

In QC mode, the adapter has 9v/1.67A, after connected the Galaxy note 5 we saw 1.23A is operating.

Right at the moment, we have faced a problem that is the charger ic side current will be 0.44A to 0.30A( depending on the supply current from adapter or over voltage and current protection).

The battery we gonna use has 3.7V 2200mAh in actual spec capacity. (sorry for my previous information)
It will take long time to charge the battery

I think we need to boost up the current level more, I am not sure what would be its value.

Can I use  Howland Current Pump in this purpose? www.ti.com/.../snoa474a.pdf

If you have any idea about this solution, let me know please.

HW Engineer

Hasan

  • Hasan,

    Trying to force more current into VBUS than VBUS wants to draw will only cause VBUS to increase in voltage. Higher voltage is not good for the system. If you get 9V to the Note 5 (after it asks for it) and it draws 1.23A instead of 1.67 Amp then that is the Note 5's fault.

    The Howland is for linear signal processing and isn't an efficient way to supply current in a power supply application.

    Regards,
    Ronald Michallick
    Linear Applications

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