Application ideas

L6924D

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10

Application ideas

10.1

USB battery charger

With a voltage range between 4.75V and 5.25V, and a maximum current up to 500mA, the USB

power bus is an ideal source for charging a single-cell Li-Ion battery. Since it is not possible to

rely on the USB current limit to charge the battery, a linear approach must be adopted.

the device will charge the battery in Linear mode.

Figure 28 shows an example of USB charger application schematic.

Figure 28. USB charger application

L6924D

V

IN

V

INSNS

T

PRG

ST1

ST2 SD GND

TH

V

OPRG

I

PRE

V

PRE

I

PRG

V

OSNS

V

OUT

I

END

V

REF

R1

R2

R3

R4

R5

C1

C2

C3

C4

BATTERY

PACK

V

BUS

GND

D- D+

SYSTEM

AND

USB

CONTROLLER