General Description
The XT2052 is a constant- current / constant- voltage
charger circuit for single cell lithium-ion batteries. The
device includes an internal power transistor, does not need
external current sense resistor and blocking diode in
applications. XT2052 requires minimal external
components, and meet the USB bus specification, is very
suitable for portable applications in the field.
Thermal modulation circuit can control the internal
chip temperature in a safe range when the device power
dissipation be relatively large or the ambient temperature
be higher.
When the input voltage (AC adapter or USB power
supply) power is lost, XT2052 automatically enters a low
power sleep mode, then the battery current consumption is
less than 0.1μA. Built-in protection circuits against irrigation,
when the battery voltage is higher than the input voltage,
automatically turn off built-in power MOSFET. Other
features include low input voltage latch, automatic
recharge, the battery temperature monitoring, and charge
status / charge status indication functions. XT2052 uses
thermally enhanced 8-pin small outline package ESOP8.

■ Features
Programmable charge current up to 1A
No MOSFET, sense resistor or blocking diode
required
Complete linear charger in small package for single
cell lithium-ion batteries
Constant-current/constant-voltage operation with
thermal regulation to maximize charge rate without
risk of overheating
Charges single cell li-ion batteries directly from USB
port
Preset 4.2V
Monitor output charge current
Automatic recharge
Charge status output pin
1/10 charge current termination
40µA supply current in shutdown
2.9V trickle charge threshold
Soft-Start limits inrush current
Output with protection against anti-irrigation
Available in ESOP8 or customer order form
When you unplug VIN , the IC does not consume
battery power