MIC5209-1.8BU Micrel Inc, MIC5209-1.8BU Datasheet - Page 11

• Manufacturer Part Number: MIC5209-1.8BU
• Description: IC REG LDO 500MA 1% 1.8V TO263-5
• Manufacturer: Micrel Inc

Specifications of MIC5209-1.8BU

• Regulator Topology: Positive Fixed
• Voltage - Output: 1.8V
• Voltage - Input: 2.5 ~ 16 V
• Voltage - Dropout (typical): 0.35V @ 500mA
• Number Of Regulators: 1
• Current - Output: 500mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: TO-263-5, D²Pak (5 leads + Tab), TO-263BA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Limit (min): -

Considering worst case tolerances, the power dissipation
could be as high as:
Using the maximum junction temperature of 125°C and a θ
of 8°C/W for the SOT-223, 25°C/W for the SO-8, or 2°C/W
for the TO-263 package, the following worst-case heat-sink
thermal resistance (θ
Table 2 and Figure 6 show that the Slot-1 power supply ap-
plication can be implemented with a minimum footprint layout.
June 2006
T
T
T
T
θ
θ
θ
θ
A
A
A
A
JA
SA
SA
SA
SA
SA
SA
SA
SA
SA
Table 2. Maximum Allowable Thermal Resistance
(limit)
(limit)
SOT-223
SOT-223
SOT-223
SO-8
SO-8
SO-8
TO-263-5
TO-263-5
TO-263-5
(V
[(3.6V – 2.375V) × 320mA] + (3.6V × 4mA)
P
θ
θ
SA
SA
SA
D
JA
IN(max)
= 407mW
= θ
= θ
=
JA
JA
JA
T
T
– V
J(max)
J(max
J(max
= θ
= θ
209°C/W
209°C/W
201°C/W
201°C/W
201°C/W
184°C/W
184°C/W
184°C/W
207°C/W
207°C/W
207°C/W
40°C
40°C
40°C
OUT(max)
JC
P
P
D
D
D
SA
−
) requirements are:
T
T
A
A
A
) × I
184°C/W
184°C/W
176°C/W
176°C/W
176°C/W
159°C/W
159°C/W
159°C/W
182°C/W
182°C/W
182°C/W
50°C
50°C
50°C
OUT
+ V
160°C/W
160°C/W
152°C/W
152°C/W
152°C/W
135°C/W
135°C/W
135°C/W
158°C/W
158°C/W
158°C/W
IN(max)
60°C
60°C
60°C
× I
GND
123°C/W
123°C/W
121°C/W
121°C/W
121°C/W
115°C/W
115°C/W
115°C/W
98°C/W
98°C/W
98°C/W
75°C
75°C
75°C
JC
11
Figure 6 shows the necessary copper pad area to obtain
specifi c heat sink thermal resistance (θ
values in Table 2 require much less than 500mm
according to Figure 6, and can easily be accomplished with
the minimum footprint.
Figure 6. PCB Heat Sink Thermal Resistance
70
60
50
40
30
20
10
0
0
COPPER HEAT SINK AREA (mm
COPPER HEAT SINK AREA (mm
COPPER HEAT SINK AREA (mm )
2000
4000
SA
) values. The θ
6000
2
2
M9999-060906
2
of copper,
SA