MP26506 MPS, MP26506 Datasheet - Page 7

• Manufacturer Part Number: MP26506
• Description: 28v, Li+single-cell Battery Charger With Usb/ac-adapter Input & Reverse Polarity Protection
• Manufacturer: MPS

Charge termination in USB mode
The charge current will gradually decrease in CV
mode as the battery approaches full. The battery
full threshold can be programmed by connecting
a resistor from IBF pin to ground. When the
charge current reaches this threshold, the
charger current will be turned off. The battery
voltage may decay after termination due to self
discharge or system draw current from the
battery.
Automatic Recharge in USB mode
Upon V
automatically restart the charge cycle until the
IBF condition is met again. When the input is
unplugged or the charger is disabled and/or
terminated, the leakage current from the battery
to MP26056 is less than 1uA.
Programming of Charge Current and Battery
Full Current
The charge current (I
(R
relationship of the charge current and the
programming
following equations.
It is highly recommended to program the charge
current within 0.2A to 1A. The battery full charge
current
connecting a resistor R
GND:
The selection of R
condition, 0.1I
MP26056 Rev. 0.9
7/31/2008
I
CHG
SETX
=
I
CHG
) connecting from the I
R
1Ax1.7k
SET1
BATT
=
threshold
1Ax1.7k
// R
R
MP26056- 28V, Li+Single-Cell Battery Charger with USB/AC-Adapter Input & Reverse Polarity Protection
drops to 4.0V, the charger will
CHG
SET1
SET2
resistance
Ω
I
BF
< I
Ω
=
BF
(MOD=Low, for AC Adapter)
BF
(I
1A 1.7k
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
(MOD= High, for USB)
BF
< 0.6 I
CHG
)
value should meet the
×
BF
R
BF
) is set by resistors
is
from the IBF pin to
SETX
is
CHG.
Ω
programmed
pin to GND. The
established
The open-drain
© 2008 MPS. All Rights Reserved.
www.MonolithicPower.com
by
by
pin
When the battery full condition is reached or any
other condition prevents the charger from
charging,
Thermal Protection
The MP26056 has proprietary thermal protection
to prevent the IC from overheating. When in
thermal protection mode, the charge current
becomes a saw-tooth waveform instead of a DC
current. The average current of the saw-tooth
waveform will be lower than the programmed DC
charge
overheating. Operating in thermal protection
mode will slow down the charging process.
Lowering the input voltage and enhancing
thermal dissipation to the environment can
effectively prevent the IC from going into thermal
protection mode.
CHG
current
CHG
is used to indicate charging status.
will become a floating.
to
prevent
the
IC
from
7