MICRORAM Datasheet, PDF (5/8 Pages) Vicor Corporation – Output Ripple Attenuation Module

µRAM2xxx
PRELIMINARY
20.00
Ripple Attenuation @ 28V (Room Temp.)
20.00
Ripple Attenuation @ 5V (Room Temp.)
0.00
0.00
-20.00
-20.00
-40.00
-40.00
-60.00
-60.00
-80.00
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Freq. (Hz)
10A, 100uF Vref
10A, No Vref Cap
-80.00
10
100
1,000
10,000
100,000
1,000,000
10,000,000
Freq. (Hz)
10A, 100uF Vref
10A, No Vref Cap
Figure 3a, 3b—Curves demonstrating the small signal attenuation performance as measured on a network analyzer with a typical
module at (a) 28V and 10A output and (b) 5V and 10A. The low frequency attenuation can be enhanced by connecting a 100µF
capacitor, CHR, to the VREF pin as shown in Figures 1 and 2.
-0
Vout=3V Iload=20A
100 degrees baseplate temperature
-25
Rhr=28k (Vheadroom=90mV)
-0
27k (100mV)
26k (110mV)
25k (122mV)
24k (135mV)
23k (150mV)
22k (160mV)
-25
Vout=28V Iload=20A
100 degrees baseplate temperature
Rhr=260k (Vheadroom=90mV)
250k (100mV)
240k (110mV)
230k (122mV)
220k (135mV)
210k (150mV)
200k (160mV)
-50
-50
-75
10Hz
100Hz
1.0KHz
... DB(V(VOUT))
10KHz
17k (260mV)
18k (240mV)
19k (217mV)
20k (197mV)
21k (180mV)
100KHz
Frequency
1.0MHz
-75
10Hz
100Hz
1.0KHz
... DB(V(VOUT))
10KHz
Frequency
150k (260mV)
160k (240mV)
170k (217mV)
180k (197mV)
190k (180mV)
100KHz
1.0MHz
Figure 4a-4b—Simulated graphs demonstrating the tradeoff of attenuation versus headroom setting at 20 Amps and an equivalent
100°C baseplate temperature at 3V and 28V.
-10
-20
Rhr=28k
27k
-30
26k
100khz 3V
500khz 3V
1Mhz 3V
25k
-40
24k
23k
-50
22k
21k
20k
19k
-60
18k
17k
-70
3.0
3.5
4.0
4.5
5.0
5.5
6.0
Watts
-10
-20
Rhr=260k
250k
-30
240k
230k
28V 20A
-40
-50
220k
210k
200k
190k
180k
-60
100khz 28V
500khz 28V
1Mhz 28V
170k
160k
150k
-70
3.0
3.5
4.0
4.5
5.0
5.5
6.0
Watts
Figure 4c-4d—MicroRam attenuation vs. power dissipation at 3V 20A, and 28V 20A.
Notes:The measurements in Figures 8-16 were taken with a µRAM2C21 and standard scope probes with a 20MHz bandwidth scope setting. The criteria for transient current
capability was as follows: The transient load current step was incremented from 10A to the peak value indicated, then stepped back to 10A until the resulting output peak to
peak was around 40mV.
Vicor Corp. Tel: [phone] Fax: [phone]
MicroRAM
Rev. 1.1
Page 5 of 8
Set your site on VICOR at www.vicorpower.com