cs8151 ON Semiconductor, cs8151 Datasheet - Page 9

• Manufacturer Part Number: cs8151
• Description: 5v, 100ma Low Dropout Linear Regulator With Watchdog, Resetbar, & Wake Up
• Manufacturer: ON Semiconductor

temperatures. The ESR of the capacitor should be less than
50% of the maximum allowable ESR found in step 3 above.
Calculating Power Dissipation
In a Single Output Linear Regulator
regulator (Figure 9) is:
where:
permissible value of R
package section of the data sheet. Those packages with
R
the die temperature below 150°C.
qJA
The maximum power dissipation for a single output
V
V
I
I
Once the value of P
The value of R
P D(max) + ( V IN(max) * V OUT(min) ) I OUT(max)
OUT(max)
Q
IN(max)
OUT(min)
application, and
I
’s less than the calculated value in equation 2 will keep
OUT(max)
V
is the quiescent current the regulator consumes at
Figure 9. Single Output Regulator with Key
IN
Performance Parameters Labeled
is the maximum input voltage,
is the minimum output voltage,
is the maximum output current for the
.
I
IN
) V IN(max) I Q
qJA
R qJA + 150°C * T A
Battery
can then be compared with those in the
qJA
REGULATOR®
D(max)
}
can be calculated:
C
C1
SMART
Control
Features
Delay
P D
is known, the maximum
I
Q
V
C
I
OUT
IN
Delay
GND
Figure 10. Application Diagram
CS8151
http://onsemi.com
V
Wake Up
OUT
(1)
(2)
RESET
CS8151
V
WDI
OUT
9
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.
Heat Sinks
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 heatsink data sheets
of heatsink manufacturers.
qJA
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
qJC
qCS
qSA
qJC
, it too is a function of package type. R
appears in the package section of the data sheet. Like
= the junction−to−case thermal resistance,
= the case−to−heatsink thermal resistance, and
= the heatsink−to−ambient thermal resistance.
C2
R qJA + R qJC ) R qCS ) R qSA
V
I/O
RESET
I/O
Microprocessor
CC
qJA
:
qCS
and R
qSA
are
(3)