AAT3698 Datasheet, PDF (12/21 Pages) Skyworks Solutions Inc. – 1.6A Linear Li-Ion Battery Charger in a 3x3 TDFN Package

DATA SHEET
AAT3698
1.6A Linear Li-Ion Battery Charger in a 3x3 TDFN Package
Constant Current Fast Charge
Battery cell preconditioning charge continues until the
battery voltage reaches the preconditioning voltage
threshold (V_MIN). At this point, the AAT3698-1/-2 begins
the constant current charge phase. The current level for
this mode is programmed using a single resistor from the
ISET pin to ground. The programmed current can be set
from a minimum of 100mA up to a maximum of 1.6A.
Constant Voltage Charge
Constant current charging will continue until the battery
voltage reaches the constant output voltage, V_CO. The
AAT3698-1/AAT3698-2 then transitions to constant volt-
age mode, in which the charge IC regulates the battery
voltage to a constant output voltage (factory programmed
to 4.2V). The charging current decreases during this
phase. The charger regulates battery voltage at 4.2V and
continues to charge the battery until the charge current
reaches the termination level set by R_TERM. When the
charge current reaches its termination level I_TERM, charg-
ing is terminated.
AAT3698-1
The charger turns off the series pass device even if the
EN pin is held low and the device automatically enters a
power-saving sleep state. During this time, the series
pass device blocks current in both directions, preventing
the battery from discharging through the IC. The device
remains in sleep mode even if the charger source is dis-
connected. When the battery terminal voltage drops
below the V_RCH threshold, the AAT3698-1 resumes charg-
ing operation if no fault is detected.
AAT3698-2
The charger regulates the battery voltage at 4.2V and
continues to charge the battery with a current lower
than the charge termination current until a logic high is
applied to the EN pin to stop charging.
ICH _CC
V CO(REG)
Battery
Voltage
Battery
Current
STAT
EN
V MIN
ICH _TRK
Preconditioning Charge
Constant Current Charge
I CH _TERM
STAT
Turns
OFF
Charger Turns OFF when
I CH_CC = I CH_TERM (AAT3698-1)
Charger Turns OFF when
EN = high (AAT3698-2)
Constant Voltage Charge
Figure 1: AAT3698-1/-2 Battery Charging Profile.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
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201902B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012