L6460 datasheet(77/139 Pages) STMICROELECTRONICS

77 / 139 page

L6460

Power bridges

Doc ID 17713 Rev 1

77/139

the regulated current: the voltage provided at the IREF_FB pin will be compared to the

internal reference. L6460 has the possibility to choose between four voltage references

using the serial interface, writing the SelCurrRef[1:0] bits in the Aux3SwCfg1 register.

Regardless of the CurrRef voltage, if the IREF_FB pin remains below the chosen threshold,

the internal current limitation will work (typical Ilimit current 4A).

The battery charge profile can be chosen by fixing the desired CurrRef and FBRef internal

reference voltages and by choosing the desired V = f(I) trans-characteristic of the external

differential amplifier.

In the Figure 22 is shown a typical Li-Ion battery charge profile.

Figure 22.

Li-ion battery charge profile

The battery charge loop control can be used to implement a buck type switching regulator.

The regulated output voltage will be externally set by a resistor divider network connected to

VREF_FB pin, as already described and the current protection will be the one implemented

internally in the Bridge4 section.

Rapid charge

phase

Time

Voltage or Current

Blue=Battery Voltage

Red=Battery Current

FBRef depending

CurrRef depending

End Of Charge

Precharge

phase

Ichrg

Iprechrg

Vchrg

Veochrg

Ieochrg

Constant V.

phase

L6460 Fiches technique(PDF) 77 Page - STMicroelectronics