Instruction Manual

Design Guide & Applications Manual
F
or Maxi, Mini, Micro Family DC-DC Converters and Configurable Power Supplies
Maxi, Mini, Micro Design Guide Rev 4.9 vicorpower.com
Page 58 of 88
Apps. Eng. 800 927.9474 800 735.6200
12. Output Ripple Attenuator Module (MicroRAM)
F
requency
10 Hz 100 Hz 1.0 KHz 10 KHz 100 KHz 1.0 MHz
... DB(V(VOUT))
-75
-50
-25
-
0
Rhr = 260 k (Vheadroom = 90 mV)
250 k (100 mV)
240 k (110 mV)
230 k (122 mV)
220 k (135 mV)
210 k (150 mV)
2
00 k (160 mV)
190 k (180 mV)
180 k (197 mV)
170 k (217 mV)
160 k (240 mV)
150 k (260 mV)
V
out = 28 V load = 20 A
100 degrees baseplate temperature
Figure 12–4b — Graph of simulated results demonstrating the tradeoff of attenuation vs. headroom setting at 20 A and a equivalent 100°C
baseplate temperature at 28 V.
17 k
18 k
19 k
20 k
21 k
22 k
23 k
24 k
25 k
26 k
27 k
Rhr=28 k
-70
-60
-50
-40
-30
-20
-10
3.0 3.5 4.0 4.5 5.0 5.5 6.0
Watts
500 khz 3 V
1 Mhz 3 V
100 khz 3 V
dB
Figure 12–4c — MicroRAM attenuation vs. power dissipation at 3 V, 20 A
Rhr = 260 k
250 k
240 k
230 k
220 k
210 k
200 k
190 k
180 k
170 k
160 k
150 k
-70
-60
-50
-40
-30
-20
-10
3.0 3.5 4.0 4.5 5.0 5.5 6.0
Watts
dB
100 khz 28 V
500 khz 28 V
1 Mhz 28 V
Figure 12–4d — MicroRAM attenuation vs. power dissipation at 28 V, 20 A
F
requency
1
0 Hz
1
00 Hz
1
.0 KHz
1
0 KHz
1
00 KHz
1
.0 MHz
.
.. DB(V(VOUT))
-75
-
50
-
25
-0
Vout = 3 V load = 20 A
100 degrees baseplate temperature
Rhr = 28 k (Vheadroom = 90 mV)
2
7 k (100 mV)
2
2 k (160 mV)
2
3 k (150 mV)
24 k (135 mV)
25 k (122 mV)
2
6 k (110 mV)
17 k (260 mV)
18 k (240 mV)
1
9 k (217 mV)
20 k (197 mV)
21 k (180 mV)
Figure 12–4a — Graph of simulated results demonstrating the tradeoff of attenuation vs. headroom setting at 20 A and a equivalent 100°C
baseplate temperature at 3 V.