APL3200 Datasheet, PDF (16/24 Pages) Anpec Electronics Coropration – Dual-Input, USB/AC Adapter, 1-Cell Li+ Charger with OVP and Thermal Regulation

APL3200
Function Description (Cont.)
External Thermistor Monitor (THRM) (Cont.)
REF
10kΩ
Thermistor
10kΩ at +25°C
THRM
100mV
TCOLD
To Regulator
THOT
Soft-Start
The APL3200 is equipped with a soft-start function to
control the rise rate of the charging current rising from
zero to the fast-charging current level in constant current
mode. During DC charger soft-start, the APL3200 ramps
up the voltage on DCI pin with constant well-controlled
slew rate. The charging current is proportional to the DCI
voltage.
The soft-start interval is 7 ms (typical) and is independent
of the fast -charging current level.
FFigure 1. Thermistor Sensing Block Diagram
Sleep Mode
The APL3200 charger circuitry enters the low-power sleep
mode if both AC adapter and USB power are removed
from the circuit. This feature prevents draining the battery
into the APL3200 during the absence of input supplies.
Note that in sleep mode, PON remains low in order for
the battery to continue supplying power to the system
load.
Table 3 Status Pin Summary
CHARGE STATE
Precharge in progress
Fast charge in progress
Charge done
Charge suspended
Sleep mode
STAT1
ON
ON
OFF
STAT2
ON
OFF
ON
OFF
OFF
I_{CHG_DC} or I_{CHG_USB}
4.2V
V_BATT
3.0V
Full Charge
Precharge Constant
Current Mode
Voltage
Mode
Charge
Done
Figure 2. Typical Charging Profile
Charge Status Outputs
The open-drain STAT1 and STAT2 outputs indicate various
charger operations are shown in Table 3. These status
pins can be used to drive LEDs or communicate to the
host processor. Note that OFF indicates the open-drain
transistor is turned off. Note that this assumes EN=High.
Copyright © ANPEC Electronics Corp.
16
Rev. A.5 - Apr., 2009
www.anpec.com.tw