LM78M05CDT National Semiconductor, LM78M05CDT Datasheet - Page 7

• Manufacturer Part Number: LM78M05CDT
• Description: IC, LINEAR VOLTAGE REGULATOR 5V TO-252-3
• Manufacturer: National Semiconductor

Specifications of LM78M05CDT

• Primary Input Voltage: 10V
• Output Voltage Fixed: 5V
• No. Of Outputs: 1
• No. Of Pins: 3
• Output Current: 500mA
• Operating Temperature Range: -40°C To +125°C
• Termination Type: SMD
• Filter Terminals: SMD
• Rohs Compliant: No
• Current Rating: 0.5A
• Dc: 03+
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Application Information
The next parameter which must be calculated is the maxi-
mum allowable temperature rise, T
If the maximum allowable value for θ
≥60˚C/W for TO-220 package or ≥92˚C/W for TO-252 pack-
age, no heatsink is needed since the package alone will
dissipate enough heat to satisfy these requirements. If the
calculated value for θ
required.
As a design aid, Table 1 shows the value of the θ
TO-252 for different heatsink area. The copper patterns that
Mounted on a printed circuit board. Note that the case
temperature is measured at the point where the leads
FIGURE 1. Cross-sectional view of Integrated Circuit
θ
JA
= TR (max)/P
contact with the mounting pad surface
D
JA
fall below these limits, a heatsink is
R
(max):
JA
˚C/w is found to be
FIGURE 2. Power Dissipation Diagram
01048423
JA
of
7
The LM78MXX/LM341XX regulators have internal thermal
shutdown to protect the device from over-heating. Under all
possible operating conditions, the junction temperature of
the LM78MXX/LM341XX must be within the range of 0˚C to
125˚C. A heatsink may be required depending on the maxi-
mum power dissipation and maximum ambient temperature
of the application. To determine if a heatsink is needed, the
power dissipated by the regulator, P
shows the voltages and currents which are present in the
circuit.
we used to measure these θ
Application Note Section. reflects the same test results as
what are in the Table 1
shows the maximum allowable power dissipation vs. ambi-
ent temperature for theTO-252 device. shows the maximum
allowable power dissipation vs. copper area (in
TO-252 device. Please see AN1028 for power enhancement
techniques to be used with TO-252 package.
I
P
IN
D
= I
= (V
L
+ I
IN
−V
G
OUT
01048424
) I
L
+ V
IN
I
G
JA
are shown at the end of the
D
, must be calculated:
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2
) for the