LP28501 datasheet(9/10 Pages) POWER

9 / 10 page

LP28501-02

Mar.-2017

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Page 9 of 10

Preliminary Datasheet

LP28501

Battery Temperature Detection

The

LP28501

continuously

monitors

battery

temperature by measuring the voltage between the

NTC pins and ground, typically determined by a

negative temperature coefficient thermistor and an

external voltage divider. The device compares this

voltage against its internal thresholds to determine if

charging is allowed. To initiate a charge cycle, the

battery temperature must be within the VLTF to VHTF

thresholds. There is a constant current source in

NTC which is 100uA(INTC)flowing out form this pin.

So VNTC is INTC×RNTC.

When the NTC fault occurs, the STAT pin will blink to

indicate the fault.

Input Current LIMIT on ILIM and ISET

For safe operation, the LP28501 has an additional

hardware pin on ILIM to limit maximum input current

on ILIM pin. The input maximum current is set by a

resistor from ILIM pin to ground as:

ISET ramming Charge Current

The charge current is RISET rammed using a single

resistor from the ISET pin to ground. The battery

charge current is 1000 times the current out of the

ISET pin. The ISET ram resistor and the charge

current are calculated using the following equations:

Note: VRISET is 1.5Volts when VBAT>VTRIKL.

LP28501 데이터시트(PDF) 9 Page - Lowpower Semiconductor inc