USB compatible battery charger demo board with integrated
power switch for Li-Ion/Li-Polymer based on the L6924U
Features
■ Operating input voltage up to 12 V
■ Fully integrated solution with power MOSFET,
reverse blocking diode, sense resistor, and
thermal control
■ AC adapter or USB mode selection
■ Programmable charge current for both AC
adapter and USB power sources separately
■ Low power/high power selection in USB mode
■ Both linear and quasi-pulse operation
■ 4.2 V preset charge voltage (±1 % accuracy)
■ Programmable termination current
■ Programmable charge timer
■ Status outputs to drive LEDs or host processor
interface
■ Battery absence detection
■ Closed loop thermal control
■ NTC or PTC thermistor interface for battery
temperature monitoring and protection
■ RoHS compliant
STEVAL-ISA076V2
Data brief
STEVAL-ISA076V2
Description
The STEVAL-ISA076V2 demonstration board is
based on the L6924U which is a fully monolithic
battery charger dedicated to single-cell LiIon/Polymer battery packs. It is the ideal solution
for space-limited applications, such as PDAs,
handheld equipment, cellular phones, and digital
cameras.
When an external voltage regulated adapter or
USB port is used, the L6924U works in linear
mode, and charges the battery in a constant
current/constant voltage (CC/CV) profile.
Moreover, when a current-limited adapter is used,
the device can operate in Quasi-Pulse Mode,
dramatically reducing the power dissipation.
February 2011 Doc ID 18138 Rev 1 1/4
For further information contact your local STMicroelectronics sales office.
www.st.com
4
Schematic diagram STEVAL-ISA076V2
AC adapter or USB
C1
R6
R5
D2 D1
C4
C3
J2
J1
µC
NTC
Battery
SHDN
GND MODE ISEL
V
REF
TH
ST1
ST2
V
IN
T
PRG
V
OUT
R1
R2
R3
J3
J5
J4
C2
R4 RT1
L6924U
I
END
I
USB
I
AC
V
OSNS
V
INSNS
V
IN
V
IN
1 Schematic diagram
Figure 1. Schematic
2/4 Doc ID 18138 Rev 1
AM08551V1