DocID022816 Rev 2

7/19

AN4050

L6924D operation in solar powered applications

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L6924D operation in solar powered applications

Thanks to its very low minimum input voltage (down to 2.5 V), the L6924D can also work as

a quasi-pulse charger when powered from a current limited adapter such as a PV panel or a

current limit device such as the SPV1040 step-up.

To work in this condition, it is enough to set the device's charging current (by R14) higher

than the maximum peak current of the PV panel. During the fast-charge phase, the output

voltage of the SPV1040 that supplies the L6924D goes down to the battery voltage plus the

voltage drop across the power MOSFET of the charger.

In this mode, the L6924D charges the battery with the same three phases as in linear mode,

but the power dissipation is greatly reduced, as shown in

Figure 7.

Figure 7. Typical charge curve in Quasi-pulse mode