LP28013A-01

Oct.-2018

www.lowpowersemi.com

Page 6 of 7

Preliminary Datasheet

LP28013A

Automatic Recharge

charge target, the LP28013A reduces its charge current to

0µA. This ensures the safety of the battery. Also, the CV

control loop always monitors the battery voltage such that it

will automatically recharge the battery when it is depleted

below the target level. This ensures that the battery is kept at

or near a fully charged condition and eliminates the need for

periodic charge cycle initiations.

Charge Status Indicator (CHAG & PG)

After application of a 5V source, the input voltage rises above

impedance path to ground.

CHRG has two different states: strong pull-down (~5mA) and

high impedance. The strong pull-down state indicates that the

LP28013A is in a charge cycle. When the charger is entered

CV mode and Once the charge current has reduced to the

battery full charge current threshold (IBF), the CHRG pin will

become high impedance, though the battery may be still

charging.

Function

CHRG

Floating

High

Charging

Low

High

Function

PG

VIN<UVLO

High

UVLO<VIN<OVP

Low

OVP<VIN

High

Enable Function

The LP28013A features an enable/disable function. An input

“Low” signal at EN pin or if this pin is floating will enable the IC.

To assure the charger will switch on, the EN turn on control

level must below 0.4 volts. The charger IC will go into the

shutdown mode when the voltage on the EN pin is greater

than 2.4 volts. If the enable function is not needed in a specific

application, it may be tied to GND or floating to keep the

charge IC in a continuously on state.

Thermal Limiting

charge current if the die temperature attempts to rise above a

preset value of approximately 125°C. This feature protects the

LP28013A from excessive temperature and allows the user to

push the limits of the power handling capability of a given

circuit board without risk of damaging the LP28013A. The

charge current can be set according to typical (not Worst-case)

ambient temperature with the assurance that the charger will

automatically reduce the current in worst-case conditions.

Power Dissipation

The conditions that cause the LP28013A to reduce charge

current through thermal feedback can be approximated by

considering the power dissipated in the IC. Nearly all of this

power dissipation is generated by the internal MOSFET

calculated to be approximately:

Where PD is the power dissipated, VIN is the input supply

voltage, VBAT is the battery voltage and IBAT is the charge

current. The approximate ambient temperature at which the

thermal feedback begins to protect the IC is: