APL3200 View Datasheet(PDF) - Anpec Electronics
Part Name
Description
Manufacturer
APL3200
Anpec Electronics
APL3200 Datasheet PDF : 24 Pages
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APL3200
Function Description
Autonomous Power Source Selection
DC Power-OK ( DCOK)
The APL3200 charges a single-cell Li+ battery from either
USB power sources or AC adapter sources. The APL3200
includes voltage sensing, monitoring the voltage on the
DC pin, and switchover circuitry that selects the active
input source to supply charging current. When both inputs
are active, priority is given to the AC adapter. Table 1
describes the switchover between AC adaptor and USB
power sources.
Table 1 USB and DC Input Selection
DC
VDC>18V
VDC<18V
USB
VUSB<6.5V
VUSB>6.5V
4V<VDC<6.4V VUSB<6.5V
VDC <4V or
VDC >6.4V
VDC <4V or
VDC >6.4V
VUSB>4V
VUSB<4V
Description
Exceeds operating input
range. Not allowed.
DCLV supplies charging
current.
USB supplies charging
current.
No charging.
When power is connected to DC, the APL3200 requires
20ms to validate the input. Consequently, charging is
interrupted for 20ms until it is determined that input power
is good. Also, when DC power is removed while valid
USB power is present, charging is interrupted for 20ms
before transferring to the USB source.
An additional power selection circuit selects one of the
power sources for control circutry of APL3200. The higher
voltage on either DCLV or USB supplies control circutry
with bias current through the selected internal MOSFET
connected from DCLV or USB to BYP. BYP is the bypass
connection for the APL3200’s internal power rail. Bypass
to the GND with a 2.2µF or greater capacitor to reduce
voltage ripple.
Enable (EN)
The enable input, EN, switches the charging of APL3200
on or off. With EN high, the APL3200 can begin charging.
When EN is low, DCOK and PON remain active. Charging
stops when EN is low, but the chip remains biased and
continues to draw current from the input supplies.
Therefore, power-monitoring outputs can remain valid.
DCOK is an active-low and open-drain output that goes
low when VDC is below 6.4V and above 3.65V. DCOK can
be used as a logic output or to drive an external P-channel
MOSFET. This allows the charger to protect the input
from over-voltage up to 18V. Charging from AC adaptor is
disabled for inputs over 6.4V. An external 1kΩ pull-up
resistor keeps DCOK high (external MOSFET off) until it
is the certain voltage within the acceptable range. To verify
that the input voltage is stable, DCOK has an internal
delay of 20ms before connecting power to DCLV. DCOK
remains operational when EN is low (charger off).
USB Power-OK ( UOK)
UOK is an active-low and open-drain output that goes low
to indicate that VUSB is valid (greater than 3.65V). UOK
remains operational when EN is low (charger off). An
external 10kΩ pullup resistor keeps UOK high until it is
certain that power is within the acceptable range for 20ms.
UOK can be used as a logic output, or to control a MOSFET
that switches USB power directly to the system load when
the APL3200 is powered from a USB source.
Power On (PON)
PON goes high when V or V is within its normal
DC
USB
operating range(3.65V<V <6.4V or V >3.65V) to turn
DC
USB
off the external P-channel MOSFET, disconnecting the
battery from system load. Also, PON can be used as a
logic output to indicate power is connected.
The PON has an internal 10Ω MOSFET for pulling up to
BYP voltage and an internal 120kΩ resistor for pulling
down to the GND.
Precharge Current
When the APL3200 is powered with a battery connected,
the IC first detects if the cell voltage is ready for full charge
current. If the cell voltage is less than the prequal level
(3V typ.), the battery is precharged with a 50mA current
until the cell reaches the proper level. The full charging
current, as set by USEL or DCI, is then applied.
Copyright © ANPEC Electronics Corp.
14
Rev. A.5 - Apr., 2009
www.anpec.com.tw
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