NCP662, NCV662, NCP663, NCV663
http://onsemi.com
7
APPLICATIONS INFORMATION
A typical application circuit for the NCP662/NCV662
and NCP663/NCV663 series are shown in Figure 1 and
Figure 2.
Input Decoupling (C1)
A 1.0 F capacitor, either ceramic or tantalum is
recommended and should be connected close to the device
package. Higher capacitance values and lower ESR will
improve the overall line transient response.
TDK capacitor: C2012X5R1C105K or C1608X5R1A105K
Output Decoupling (C2)
The NCP662/NCV662 and NCP663/NCV663 are very
stable regulators and do not require any specific Equivalent
Series Resistance (ESR) or a minimum output current.
Capacitors exhibiting ESRs ranging from a few m up to
10 can safely be used. The minimum decoupling value is
0.1 F and can be augmented to fulfill stringent load
transient requirements. The regulator accepts ceramic chip
capacitors as well as tantalum devices. Larger values
improve noise rejection and load regulation transient
response.
TDK capacitor: C2012X5R1C105K, C1608X5R1A105K,
or C3216X7R1C105K
Enable Operation (NCP662/NCV662 ONLY)
The enable pin will turn on the regulator when pulled high
and turn off the regulator when pulled low. The threshold
limits are covered in the electrical specification section of
the data sheet. If the enable is not used, the pin should be
connected to V
in
.
Hints
Please be sure the Vin and GND lines are sufficiently
wide. When the impedance of these lines is high, there is a
chance to pick up noise or cause the regulator to
malfunction.
Place external components, especially the output
capacitor, as close as possible to the circuit, and make leads
as short as possible.
Thermal
As power across the NCP662/NCV662 and
NCP663/NCV663 increases, it might become necessary to
provide some thermal relief. The maximum power
dissipation supported by the device is dependent upon board
design and layout. The mounting pad configuration on the
PCB, the board material, and the ambient temperature effect
the rate of temperature rise for the part. This is stating that
when the devices have good thermal conductivity through
the PCB, the junction temperature will be relatively low with
high power dissipation applications.
The maximum dissipation the package can handle is
given by:
PD +
T
J(max)
*T
A
R
JA
If junction temperature is not allowed above the
maximum 125C, then the NCP662/NCV662 and
NCP663/NCV663 can dissipate up to 300 mW @ 25C.
The power dissipated by the NCP662/NCV662 and
NCP663/NCV663 can be calculated from the following
equation:
P
tot
+
ƪ
V
in
*I
gnd
(I
out
)
ƫ
)
[
V
in
* V
out
]
*I
out
or
V
inMAX
+
P
tot
)
V
out
*
I
out
I
gnd
) I
out
If an 100 mA output current is needed then the ground
current from the data sheet is 2.5 A. For the
NCP662/NCV662 or NCP663/NCV663 (3.0 V), the
maximum input voltage is 6.0 V.
