NON-ISOLATED DC/DC CONVERTERS
2.4 Vdc - 5.5 Vdc Input, 0.6 Vdc - 3.63 Vdc /6 A Outputs
January 13, 2011
Bel Power, Inc. , a subsidiary of Bel Fuse, Inc.
Tunable LoopTM (continued)
Table 2.General recommended values of RTUNE and CTUNE for Vin=5V and various external ceramic capacitor
combinations.
Co
1x47μF
47
2x47μF
47
4x47μF 6x47μF 10x47μF 20x47μF
RTUNE
CTUNE
47
33
33
33
4700pF
10nF
33nF
47nF
56nF
68nF
Table 3.Recommended values of RTUNE and CTUNE to obtain transient deviation of ≤2% of Vout for a 3A step
load with Vin=5V.
Vo
Co
3.3V
2.5V
1.8V
1.2V
0.6V
1 x 47μF + 6 x 47μF +
330uF
Polymer
3 x 47μF 4 x 47μF 5 x 47μF
330uF
Polymer
RTUNE
CTUNE
ΔV
100
15nF
58mV
56
47
33
33
18nF
45mV
27nF
34mV
47nF
24mV
39nF
12mV
Table 4. General recommended values of RTUNE and CTUNE for Vin=3.3V and various external ceramic capacitor
combinations.
Co
1x47μF
47
2x47μF
47
4x47μF 6x47μF 10x47μF 20x47μF
RTUNE
CTUNE
47
33
33
33
10nF
15nF
39nF
47nF
68nF
82nF
Table 5. Recommended values of RTUNE and CTUNE to obtain transient deviation of ≤2% of Vout for a 3A step
load with Vin=3.3V.
Vo
Co
2.5V
1.8V
1.2V
0.6V
2 x 47μF +
330uF
Polymer
2 x 330uF
Polymer
6 x 47μF 6 x 47μF
RTUNE
CTUNE
ΔV
33
33
33
33
47nF
46mV
47nF
33mV
68nF
24mV
220nF
12mV
Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302 • Tel 201-432-0463 • Fax 201-432-9542 • www.belfuse.com
19
BEL [ BEL FUSE INC. ]
