MIC5256 Micrel Semiconductor, MIC5256 Datasheet - Page 10

• Manufacturer Part Number: MIC5256
• Description: 150mA UCap LDO with Error Flag
• Manufacturer: Micrel Semiconductor

MIC5256
The junction-to-ambient thermal resistance for the minimum
footprint is 235 C/W, from Table 1. The maximum power
dissipation must not be exceeded for proper operation. Using
the output voltage of 3.0V and an output current of 150mA,
the maximum input voltage can be determined. Because this
device is CMOS and the ground current is typically 100 A
over the load range, the power dissipation contributed by the
ground current is < 1% and can be ignored for this calculation.
Therefore, a 3.0V application at 150mA of output current can
accept a maximum input voltage of 5.4V 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
lators
MIC5256
315mW = (V
315mW = V
810mW = V
V
handbook.
IN(max)
= 5.4V
Designing with Low-Dropout Voltage Regu-
IN
IN
IN
·150mA – 450mW
·150mA
– 3.0V) 150mA
10
Fixed Regulator Applications
Figure 1 shows a standard low-noise configuration with a
47k pull-up resistor from the error flag to the input voltage
and a pull-down capacitor to ground for the purpose of fault
indication. EN (Pin 3) is connected to IN (Pin 1) for an
application where enable/shutdown is not required. C
1.0 F minimum.
Figure 1. Low-Noise Fixed Voltage Application
C
Ceramic
IN
= 1.0 F
V
IN
MIC5256-x.xBM5
1
2
3
47k
5
4
V
OUT
C
Ceramic
OUT
= 1.0 F
June 2003
Micrel
OUT
=