MC33375 ON Semiconductor, MC33375 Datasheet - Page 10

• Manufacturer Part Number: MC33375
• Description: Low Dropout Voltage Regulator
• Manufacturer: ON Semiconductor

THERMAL PROTECTION
the integrated circuit in the event that the maximum junction
temperature is exceeded. When activated, typically at
150°C, the output is disabled. There is no hysteresis built
into the thermal protection. As a result the output will appear
to be oscillating during thermal limit. The output will turn
off until the temperature drops below the 150°C then the
output turns on again. The process will repeat if the junction
increases above the threshold. This will continue until the
existing conditions allow the junction to operate below the
temperature threshold.
heatsinking.
Internal thermal limiting circuitry is provided to protect
Thermal limit is not a substitute for proper
180
160
140
120
100
80
60
Figure 25. SOT−223 Thermal Resistance and Maximum
170
150
130
110
0
90
70
50
30
Figure 26. SOP−8 Thermal Resistance and Maximum
Minimum
Size Pad
Power Dissipation versus P.C.B. Copper Length
0
Power Dissipation versus P.C.B. Copper Length
5.0
P
10
L, LENGTH OF COPPER (mm)
D(max)
L, LENGTH OF COPPER (mm)
R
MC33375 Series
10
qJA
http://onsemi.com
for T
20
A
R
15
Graph Represents Symmetrical Layout
= 50°C
qJA
L
10
Î Î Î Î Î Î Î
Î Î Î Î Î Î Î
Î Î Î Î Î Î Î
P
Copper
450 mA. If during current limit the junction exceeds 150°C,
the thermal protection will protect the device also. Current
limit is not a substitute for proper heatsinking.
OUTPUT NOISE
present at the output. Reducing the regulator bandwidth by
increasing the size of the output capacitor will reduce the
noise on the MC33375.
ON/OFF PIN
should not be left floating. The pin should be pulled high for
the MC33375 to operate.
2.0 oz.
D(max)
L
The internal current limit will typically limit current to
In many applications it is desirable to reduce the noise
When this pin is pulled low, the MC33375 is off. This pin
30
20
2.0 oz. Copper
for T
L
Î Î Î
Î Î Î
Î Î Î
A
25
= 50°C
L
40
3.0
mm
30
1.6
1.4
1.2
1.0
0.8
0.6
0.4
50
3.2
2.8
2.4
2.0
1.6
1.2
0.8
0.4