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MicroRAM

Rev. 1.1

Page 5 of 8

µRAM2xxx

Ripple Attenuation @ 28V (Room Temp.)

-80.00

-60.00

-40.00

-20.00

0.00

20.00

10

100

1,000

10,000

100,000

1,000,000

10,000,000

Freq. (Hz)

10A, 100uF Vref

10A, No Vref Cap

Ripple Attenuation @ 5V (Room Temp.)

-80.00

-60.00

-40.00

-20.00

0.00

20.00

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

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.

Figure 4c-4d—MicroRam attenuation vs. power dissipation at 3V 20A, and 28V 20A.

Frequency

10Hz

100Hz

1.0KHz

10KHz

100KHz

1.0MHz

...

DB(V(VOUT))

-75

-50

-25

-0

Vout=3V Iload=20A

100 degrees baseplate temperature

Rhr=28k (Vheadroom=90mV)

27k (100mV)

22k (160mV)

23k (150mV)

24k (135mV)

25k (122mV)

26k (110mV)

17k (260mV)

18k (240mV)

19k (217mV)

20k (197mV)

21k (180mV)

Frequency

10Hz

100Hz

1.0KHz

10KHz

100KHz

1.0MHz

...

DB(V(VOUT))

-75

-50

-25

-0

Rhr=260k (Vheadroom=90mV)

250k (100mV)

240k (110mV)

230k (122mV)

220k (135mV)

210k (150mV)

200k (160mV)

190k (180mV)

180k (197mV)

170k (217mV)

160k (240mV)

150k (260mV)

Vout=28V Iload=20A

100 degrees baseplate temperature

17k

18k

19k

20k

21k

22k

23k

24k

25k

26k

27k

Rhr=28k

-70

-60

-50

-40

-30

-20

-10

3.0

3.5

4.0

4.5

5.0

5.5

6.0

Watts

500khz 3V

1Mhz 3V

100khz 3V

28V 20A

Rhr=260k

250k

240k

230k

220k

210k

200k

190k

180k

170k

160k

150k

-70

-60

-50

-40

-30

-20

-10

3.0

3.5

4.0

4.5

5.0

5.5

6.0

Watts

100khz 28V

500khz 28V

1Mhz 28V

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.