AAT3673 Datasheet, PDF (15/28 Pages) Skyworks Solutions Inc. – 1.6A Dynamic Battery Charger and Power Manager

DATA SHEET
AAT3673
1.6A Dynamic Battery Charger and Power Manager
Fast Charge/Constant Current Charging
Battery cell preconditioning continues until the voltage
measured by the internal sense circuit exceeds the pre-
conditioning voltage threshold (V_MIN). At this point, the
AAT3673 begins the fast charge constant current phase.
The fast charge constant current (I_{CH_CC}) level is pro-
grammed by the user via the R_ADP resistor. The AAT3673
remains in constant current charge mode until the bat-
tery reaches the voltage regulation point, V_CO(REG). The
formula for fast charge current as a function of current
setting resistor is:
2V
I_{CH_CC} = K_{I_CC_ADP} · _RADP
Alternately, to select the resistor value for a given
charging current use:
2V
R_ADP = K_{I_CC_ADP} · _{ICH_CC}
where K_{I_CC_ADP} = 29300 (typical).
Constant Voltage Charging
The charge control system transitions to a regulated con-
stant voltage phase from the constant current fast charge
mode when the battery voltage reaches the end of charge
regulation threshold (V_CO(REG)). The regulation voltage
level is factory programmed to 4.2V (±1%). The charge
current in the constant voltage mode drops as the bat-
tery cell under charge reaches its maximum capacity.
Battery
UVLO
Trickle
Charge
Constant Current
Charge Phase (CC)
V_{CO( REG)}
V_RCH
I _{CH_CC}
Constant Voltage
Charge Phase (CV)
Termination
Phase
Constant Current
Charge Phase
Constant Voltage
Charge Phase
Recharge Phase
I _{CH_ CC}
Termination
Phase
V_MIN
V_UVLO
I_{CH_ TKL}
I_{CH_ TERM}
when
V_BAT =
V_{CO( REG)}
I_{CH_ TERM}
when
V_BAT =
V_{CO( REG)}
Figure 1: Current vs. Voltage and Charger Time Profile.
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
201881B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 25, 2012
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