LP28021-04

Apr.-2017

www.lowpowersemi.com

Page 9 of 11

Preliminary Datasheet

LP28021

Thermal Limiting

An internal thermal feedback loop reduces the IBAT

rammed charge current if the die temperature

attempts to rise above a preset value of

approximately 150℃. This feature protects the

LP28021 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 LP28021. 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.

TDFN

power

considerations

are

discussed further in the Applications Information

section.

Charge Status Indicator

The charge status output has two different states:

strong pull-down (~5mA) and high impedance. The

strong pull-down state indicates that the LP28021 is

in a charge cycle. Once the charge cycle has

terminated, the pin state is determined by under

voltage lockout conditions. High impedance indicates

that the LP28021 is in under voltage lockout mode:

either VO is less than 100mV above the BAT pin

voltage or insufficient voltage is applied to the VO pin.

A microprocessor can be used to distinguish

between these two states—this method is discussed

in the Applications Information section. When VIN

rise above 6.1V(typ.), the CHRG and STDBY LEDs

would be turned off. A microprocessor can be used

to distinguish between these two states.

Function

CHRG

STDBY

Charging

low

high

Charge Complete

high

low