NCV97310MW33GEVB
http://onsemi.com
8
The modulation depth and modulation frequency are each
set by 2 external resistors to GND. The modulation
frequency can be set from 5 kHz up to 50 kHz using
a resistor from the RMOD pin to GND. The modulation
depth can be set from 3% up to 30% of the nominal switching
frequency using a resistor from the RDEPTH pin to GND.
Please see the curves below for typical values:
Modulation Frequency vs. RMOD
RMOD (k
W
)
Modulation Frequency (kHz)
0
2.00
7.00
12.00
17.00
22.00
27.00
32.00
37.00
42.00
47.00
52.00
40
50
60
10
20
30
RDEPTH (k
W
)
Modulation Depth (%FSW)
0
0.0%
40
50
60
10
20
30
Modulation Depth vs. RDEPTH
5.0%
10.0%
15.0%
20.0%
25.0%
30.0%
Spread spectrum is automatically turned off when there is
a short to GND or an open circuit on either the RMOD pin
or the RDEPTH pin. Please be sure that the ROSC pin is an
open circuit when using spread spectrum.
TYPICAL PERFORMANCE
Efficiency
Figure 6. Efficiency for SW1 with a 3.3 V Output
NCV97310 − SW1 Efficiency − 3.3 V
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.5
0
1
1.5
2
2.5
3
3.5
Output Current (A)
Efficiency
VIN = 8.0 V
VIN = 13.2 V
VIN = 18.0 V
