Preliminary Datasheet

LP28012

LP28012 – 00

Feb.-2014

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Page 8 of 10

Example: Consider the extreme case when an LP28012 is

operating from a 6V supply providing 250mA to a 3V Li-Ion

battery, the switching regulator and the LDO are off. The

ambient temperature above which the LP28012 will begin to

reduce the 250mA charge current is approximately:

copper board, the LP28012 has a thermal resistance of

approximately 43°C/W.)

T =

If there is more power dissipation due to the switching

regulator or the LDO, the thermal regulation will kick in at a

somewhat lower temperature than this. In the above

circumstances, the LP28012 can be used above 82.75°C, but

the charge current will be reduced from 250mA. The

approximate current at a given ambient temperature can be

calculated:

o

o

o

Note: 1V = 1J/C = 1W/A

Furthermore, the voltage at the ISET pin will change

proportionally with the charge current as discussed in the

ISET ramming Charge Current section.