NCV8502 ON Semiconductor, NCV8502 Datasheet - Page 11

• Manufacturer Part Number: NCV8502
• Manufacturer: ON Semiconductor

regulator (Figure 19) is:
P D(max) + [V IN(max) * V OUT(min) ] I OUT(max)
where:
permissible value of R
package section of the data sheet. Those packages with
R
the die temperature below 150 C.
dissipate the heat generated by the IC, and an external
heatsink will be required.
qJA
The maximum power dissipation for a single output
V
V
I
application, and
I
I
Once the value of P
The value of R
In some cases, none of the packages will be sufficient to
OUT(max)
Q
OUT(max)
IN(max)
OUT(min)
CALCULATING POWER DISSIPATION IN A
’s less than the calculated value in equation 2 will keep
is the quiescent current the regulator consumes at
V
Figure 19. Single Output Regulator with Key
SINGLE OUTPUT LINEAR REGULATOR
IN
Performance Parameters Labeled
is the maximum input voltage,
.
) V IN(max) I Q
is the minimum output voltage,
is the maximum output current for the
I
IN
qJA
R QJA + 150°C *
can then be compared with those in the
qJA
REGULATOR
D(max)
}
can be calculated:
SMART
Control
Features
is known, the maximum
P D
I
Q
T A
I
OUT
NCV8502 Series
http://onsemi.com
V
OUT
(1)
(2)
11
package to improve the flow of heat away from the IC and
into the surrounding air.
outside environment will have a thermal resistance. Like
series electrical resistances, these resistances are summed to
determine the value of R
where:
R
functions of the package type, heatsink and the interface
between them. These values appear in heat sink data sheets
of heat sink manufacturers.
qJA
A heat sink effectively increases the surface area of the
Each material in the heat flow path between the IC and the
R
R
R
R
Figure 20. 16 Lead SOW (Exposed Pad), qJA as a
qJC
qCS
qSA
qJC
100
Thickness), Board Material = 0.0625, G−10/R−4
, it too is a function of package type. R
90
80
70
60
50
40
Function of the Pad Copper Area (2 oz. Cu
= the junction−to−case thermal resistance,
appears in the package section of the data sheet. Like
0
= the case−to−heatsink thermal resistance, and
= the heatsink−to−ambient thermal resistance.
R QJA + R QJC ) R QCS ) R QSA
200
HEAT SINKS
Copper Area (mm
qJA
:
400
2
)
qCS
600
and R
qSA
800
are
(3)