CS9201 ON Semiconductor, CS9201 Datasheet - Page 5

• Manufacturer Part Number: CS9201
• Description: Micropower 5v, 100ma Low Dropout Linear Regulator With Nocap(tm)
• Manufacturer: ON Semiconductor

regulator (Figure 10) is:
where:
permissible value of R
V
The maximum power dissipation for a single output
V
V
I
application, and
I
I
Once the value of P
IN
OUT(max)
Q
OUT(max)
IN(max)
OUT(min)
P D(max) + { V IN(max) * V OUT(min) } I OUT(max)
CALCULATING POWER DISSIPATION IN A
is the quiescent current the regulator consumes at
SINGLE OUTPUT LINEAR REGULATOR
Figure 10. Single output regulator with key
I
IN
performance parameters labeled.
is the maximum input voltage,
.
is the minimum output voltage,
is the maximum output current for the
) V IN(max) I Q
R QJA + 150°C * T A
JA
CS9201
D(max)
can be calculated:
I
P D
Q
is known, the maximum
I
OUT
http://onsemi.com
V
(1)
(2)
OUT
CS9201
5
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.
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:
Like R
R
interface between them. These values appear in heat sink
data sheets of heat sink manufacturers.
The value of R
In some cases, none of the packages will be sufficient to
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
JA
SA
JC
CS
SA
JC
’s less than the calculated value in equation 2 will keep
are functions of the package type, heatsink and the
= the junction–to–case thermal resistance,
appears in the package section of the data sheet.
JA
= the case–to–heatsink thermal resistance, and
= the heatsink–to–ambient thermal resistance.
, it too is a function of package type. R
R QJA + R QJC ) R QCS ) R QSA
JA
can then be compared with those in the
HEAT SINKS
JA
:
CS
and
(3)