AAT3783_12 Datasheet, PDF (10/20 Pages) Skyworks Solutions Inc. – 1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection

DATA SHEET
AAT3783
1-A Linear Li-Ion/Polymer Battery Charger with 28V Over-Voltage Protection
Functional Block Diagram
INCHR
IN
IN
OVP
Over-Current
Protection
ENOVP
FLT
OVP
Sense
and
Control
Current
Compare
Constant
Current
Reverse Blocking
CV/Pre-
Charge
Charge
Control
UVLO
BAT
BAT S
ADPP
Power
Detection
Over
Temp.
Protect
Thermal
Loop
ISET
TERM
ENCHR
GND
Charge
Status
STAT
CT
TS
Functional Description
The AAT3783 is a high performance battery charger
designed to charge single cell Lithium-Ion or Polymer
batteries with up to 1000mA of current from an external
power source. It is a stand-alone charging solution, with
just one external component required (two more for
options) for complete functionality. Also included is input
voltage protection (OVP) to up to +28V. OVP consists of
a low resistance P-channel MOSFET in series with the
charge control MOSFET, and also consists of under-volt-
age lockout protection, over-voltage monitor, and fast
shut-down circuitry with a fault output flag.
Battery Charging Operation
Figure 1 illustrates the entire battery charging profile or
operation, which consists of three phases:
1. Preconditioning (Trickle) Charge
2. Constant Current Charge
3. Constant Voltage Charge
Battery Preconditioning
Battery charging commences only after the AAT3783
checks several conditions in order to maintain a safe
charging environment. The input supply must be above
the minimum operating voltage (V_UVLO) and the enable
pin must be high. When the battery is connected to the
BAT pin, the AAT3783 checks the condition of the battery
and determines which charging mode to apply. If the
battery voltage is below the preconditioning voltage
threshold, V_MIN, then the AAT3783 begins precondition-
ing the battery cell (trickle charging) by charging at 10%
of the programmed constant current. For example, if the
programmed current is 500mA, then the preconditioning
mode (trickle charge) current is 50mA. Battery cell pre-
conditioning (trickle charging) is a safety precaution for
deeply discharged cells and will also reduce the power
dissipation in the internal series pass MOSFET when the
input-output voltage differential is at the greatest poten-
tial.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
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201903B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012