MIC5216 Datasheet, PDF (9/12 Pages) Micrel Semiconductor – 500mA-Peak Output LDO Regulator Preliminary Information

MIC5216
The total power dissipation of the device under these condi-
tions is the sum of the two power dissipation figures.
P_D(total) = P_D × 50mA + P_D × 500mA
P_D(total) = 151mW + 119mW
P_D(total) = 270mW
The total power dissipation of the regulator is less than the
maximum power dissipation of the SOT-23-5 package at
room temperature, on a minimum footprint board and there-
fore would operate properly.
Multilayer boards with a ground plane, wide traces near the
pads, and large supply-bus lines will have better thermal
conductivity.
For additional heat sink characteristics, please refer to Micrel
Application Hint 17, “Designing P.C. Board Heat Sinks”,
included in Micrel’s Databook. For a full discussion of heat
sinking and thermal effects on voltage regulators, refer to
Regulator Thermals section of Micrel’s Designing with Low-
Dropout Voltage Regulators handbook.
Fixed Regulator Circuits
MIC5216
V_IN
IN
OUT
EN FLG
GND
100k
Micrel
V_OUT
1µF
Figure 5. Low-Noise Fixed Voltage Regulator
Figure 5 shows a basic MIC5216-x.xBMx fixed-voltage regu-
lator circuit. A 1µF minimum output capacitor is required for
basic fixed-voltage applications.
The flag output is an open-collector output and requires a
pull-up resistor to the input voltage. The flag indicates an
undervoltage condition on the output of the device.
January 2000
9
MIC5216