
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878 WWW:
http://www.aimtron.com.tw
Fax: 886-3-563-0879 Email:
service@aimtron.com.tw
1
Features
Ideal for Single-Cell (4.1 V or 4.2 V) and Li-Ion
or Li-Pol Packs
Better Than
±
1% Voltage Regulation Accuracy
With Preset Voltages
Optional Cell-Temperature Monitoring Before
and During Charge
Integrated Voltage and Current Regulation With
Programmable Charge-Current and High or
Low-Side Current Sensing
Charge Status Output for Single or Dual Led or
Host Processor Interface
Automatic Battery-Recharge Feature
Charge Termination by Minimum Current
Automatic Low-Power Sleep Mode When VCC
is Removed
Requires Small Number of External
Components
Packaging: 8-Pin MSOP
Applications
1-Cell Lithium-Ion And Lithium-Polymer
Charger
DSC
General Description
The AT1457 series Lithium-Ion (Li-Ion) and
Lithium-Polymer (Li-Pol) linear charge ICs are
designed for cost-sensitive and compact portable
electronics. They combine high-accuracy current
and voltage regulation, battery conditioning,
temperature monitoring, charge termination, and
charge-status indication in a single 8-pin IC.
MSOP package options are offered to fit a wide
range of end applications.
The AT1457 continuously measures battery
temperature using an external thermistor. For
safety, the AT1457 inhibits charge until the battery
temperature is within user-defined thresholds.
The AT1457 then charges the battery in three
phases: conditioning, constant current, and
constant voltage. If the battery voltage is below the
low-voltage threshold, V(min), the AT1457
precharges using a low current to condition the
battery.
The
conditioning
approximately 10% of the regulation current. After
conditioning, the AT1457 applies a constant
current to the battery. An external sense-resistor
sets the current. The sense-resistor can be on either
the high or low side of the battery without
additional components. The constant-current phase
continues until the battery reaches the charge-
regulation voltage. The AT1457 then begins the
constant-voltage phase. The accuracy of the
voltage regulation is better than
±
1% over the
operating- temperature and supply-voltage ranges.
For single cells, the AT1457 is offered in two
fixed-voltage versions: 4.1 V, and 4.2 V. Charge
stops when the current tapers to the charge
termination threshold, I
(TERM)
. The AT1457
automatically restarts the charge if the battery
voltage falls below the V
(RCH)
threshold.
charge
rate
is
Aimtron reserves the right without notice to change this circuitry and
specifications.