MIC5248
ground current is < 1% and can be ignored for this calculation.
315mW = (V
IN
– 1.2V) 150mA
315mW = V
IN
×150mA
– 195mW
510mW = V
IN
×150mA
V
IN(max)
= 3.4V
Therefore, a 1.2V application at 150mA of output current can
accept a maximum input voltage of 3.4V in a SOT-23-5
package. For a full discussion of heat sinking and thermal
effects on voltage regulators, refer to the Regulator Thermals
section of Micrel’s
Designing with Low-Dropout Voltage Regu-
lators
handbook.
Micrel
Dual-Supply Operation
When used in dual supply systems where the regulator load
is returned to a negative supply, the output voltage must be
diode clamped to ground.
MIC5248
8
November 2002