ncv8665 ON Semiconductor, ncv8665 Datasheet - Page 8

• Manufacturer Part Number: ncv8665
• Description: 150 Ma Very Low Iq Low Dropout Linear Regulator With Reset And Delay Reset
• Manufacturer: ON Semiconductor

Calculating Power Dissipation
in a Single Output Linear Regulator
regulator (Figure 12) is:
P D(max) + [V I(max) * V Q(min) ] I Q(max)
where
permissible value of R
package section of the data sheet. Those packages with
R
will keep the die temperature below 150°C.
V
Power−on−Reset
qJA
V
V
The maximum power dissipation for a single output
Once the value of P
The value of R
V
RO
Q
D
I
V
V
I
I
’s less than the calculated value in Equation NO TAG
Q(max)
q
Delay Time
I(max)
Q(min)
Reset
voltage,
voltage,
current for the application,
is the quiescent current the regulator consumes
at I
) V I(max) I q
Q(max)
qJA
R qJA + 150C *
.
can then be compared with those in the
Shutdown
Reaction
Thermal
qJA
Reset
Time
D(max)
can be calculated:
is the maximum input
is the minimum output
is the maximum output
P D
is known, the maximum
T A
Voltage Dip
at Input
Figure 11. Reset Timing
http://onsemi.com
Undervoltage
(1)
(2)
8
dissipate the heat generated by the IC, and an external
heatsink will be required.
Heatsinks
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
< Reset Reaction Time
In some cases, none of the packages will be sufficient to
A heatsink effectively increases the surface area of the
Each material in the heat flow path between the IC and the
Secondary
Figure 12. Single Output Regulator with Key
Spike
V
I
Performance Parameters Labeled
R qJA + R qJC ) R qCS ) R qSA
dV D
dt
I
I
+
at Output
Overload
Reset Charge Current
REGULATOR®
qJA
}
C D
SMART
Control
Features
:
V
Upper Timing Threshold V
Lower Timing Threshold V
Q,rt
Iq
t
t
t
t
I
Q
V
Q
DU
DL
(3)