AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Features
• Ideal for Single-Cell (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
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 charge rate is
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.
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.
Applications
•1-Cell Lithium-Ion And Lithium-Polymer
Charger
• DSC
Aimtron reserves the right without notice to change this circuitry and
specifications.
7F, No.9,PARK AVENUE. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW:
http://www.aimtron.com.tw
10/3/2006 REV:1.2
Email:
service@aimtron.com.tw
1
GMT [ GLOBAL MIXED-MODE TECHNOLOGY INC ]
