NCV47711PDAJR2G ONSEMI [ON Semiconductor], NCV47711PDAJR2G Datasheet - Page 10

• Manufacturer Part Number: NCV47711PDAJR2G
• Description: 5 V to 20 V Adjustable LDO with Adjustable Current Limit and 3.3 V Logic Compatible Enable Input
• Manufacturer: ONSEMI [ON Semiconductor]

The output voltage is calculated from the following formula.
Ignoring the bias current into the ADJ pin:
Use R
due to ADJ bias current.
Designers should consider the tolerance of R
the design phase.
Setting the Output Current Limit
350 mA by external resistor R
C
of current limit control circuitry (see Figure 1).
Where
R
V
I
I
value. The CSO voltage is proportional to output current
according to Equation 3.
external resistor R
2.55 V. Calculations of I
using equations Equation 4 and Equation 5, respectively.
Thermal Considerations
necessary to provide some thermal relief. The maximum
power dissipation supported by the device is dependent
upon board design and layout. Mounting pad configuration
on the PCB, the board material, and the ambient temperature
affect the rate of junction temperature rise for the part. When
the NCV47711 has good thermal conductivity through the
PCB, the junction temperature will be relatively low with
†For information on tape and reel specifications,including part orientation and tape sizes, please refer to our Tape and Reel Packaging
LIM
out
ORDERING INFORMATION
Specifications Brochure, BRD8011/D.
NCV47711PDAJR2G
CSO
CSO
CSO
The output current limit can be set between 10 mA and
CSO pin provides information about output current actual
Once output current reaches its limit value (I
As power in the NCV47711 increases, it might become
of 1 mF in parallel with R
2
Device
< 50 kW to avoid significant voltage output errors
V
V
CSO
out
− current limit setting resistor
− voltage at CSO pin proportional to I
− current limit value
− output current actual value
CSO
R
I
LIM
CSO
+ V
+ I
than voltage at CSO pin is typically
+
LIM
+
REF1
out
100
Output Voltage
1
100
R
1
Adjustable
CSO
or R
CSO
1 )
CSO
R
2.55
(see Figure 1). Capacitor
CSO
2.55
CSO
I
R
R
is required for stability
LIM
1
2
100
1
values can be done
1
and R
LIM
Marking
47711
2
) set by
(eq. 2)
(eq. 3)
(eq. 4)
(eq. 5)
http://onsemi.com
during
out
10
high power applications. The maximum dissipation the
NCV47711 can handle is given by:
NCV47711 soldered on 645 mm
dissipate up to 1.8 W and up to 4.3 W for 4 layers PCB (all
layers are 1 oz) when the ambient temperature (T
See Figure 18 for R
dissipated by the NCV47711 can be calculated from the
following equations:
or
Hints
wide as possible. When the impedance of these traces 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 NCV47711 and
make traces as short as possible.
Figure 18. Thermal Resistance vs. PCB Copper Area
Since T
V
180
160
120
100
220
200
140
SOIC−8 EP
(Pb−Free)
80
60
40
20
Package
in
0
0
and GND printed circuit board traces should be as
SINGLE LAYER PCB 2 oz Cu
J
P
is not recommended to exceed 150°C, then the
V
100
D
COPPER HEAT SPREADER AREA (mm
in(MAX)
+ V
P
D(MAX)
4 LAYERS PCB − all layers 1 oz Cu
in
200
[
I
thJA
q
@I
P
+
D(MAX)
out
300
versus PCB area. The power
T
J(MAX)
) I
SINGLE LAYER PCB 1 oz Cu
2500 / Tape & Reel
I
2
out
) V
R
, 1 oz copper area, FR4 can
out
400
qJA
) I
Shipping
* T
V
out
in
q
* V
A
500
I
†
out
out
A
600
2
) is 25°C.
)
(eq. 6)
(eq. 7)
(eq. 8)
700