CS8151C Cherry Semiconductor Corporation, CS8151C Datasheet - Page 7

• Manufacturer Part Number: CS8151C
• Description: 5V/ 100mA Low Dropout Linear Regulator with Watchdog/ RESET/ & Wake Up
• Manufacturer: Cherry Semiconductor Corporation

Figure 6. Single output regulator with key performance parameters
labeled.
Once the value of P
sible value of R
The value of R
the package section of the data sheet. Those packages with
R
keep the die temperature below 150¡C.
In some cases, none of the packages will be sufficient to
dissipate the heat generated by the IC, and an external
heatsink will be required.
A heat sink effectively increases the surface area of the
package to improve the flow of heat away from the IC and
into the surrounding air.
QJA
's less than the calculated value in equation 2 will
V
IN
BATTERY
I
IN
QJA
QJA
C
can then be compared with those in
1
can be calculated:
R
D(max)
QJA
}
Control
Features
=
Regulator
is known, the maximum permis-
Smart
150¡C - T
C
Delay
P
I
Q
D
C
V
IN
Delay
A
Gnd
CS8151C
I
OUT
WAKE UP
______
RESET
V
V
OUT
Application Diagram
Application Diagram
WDI
OUT
(2)
7
Each material in the heat flow path between the IC and
the outside environment will have a thermal resistance.
Like series electrical resistances, these resistances are
summed to determine the value of R
where:
R
R
are functions of the package type, heatsink and the inter-
face between them. These values appear in heat sink data
sheets of heat sink manufacturers.
QJC
QJA
R
R
R
QJC
QCS
QSA
, it too is a function of package type. R
appears in the package section of the data sheet. Like
= the junctionÐtoÐcase thermal resistance,
= the caseÐtoÐheatsink thermal resistance, and
= the heatsinkÐtoÐambient thermal resistance.
C
2
R
QJA
= R
QJC
Heat Sinks
______
RESET
V
I/O
I/O
+ R
CC
Microprocessor
QCS
+ R
QJA
QSA
:
QCS
and R
QSA
(3)