ISL55210-ABEVAL1Z Intersil, ISL55210-ABEVAL1Z Datasheet - Page 4

• Manufacturer Part Number: ISL55210-ABEVAL1Z
• Description: Amplifier IC Development Tools ISL55210 Eval Diff. Amp, Active Balun
• Manufacturer: Intersil
• Type: Differential Amplifiersr
• Series: ISL55210r

Specifications of ISL55210-ABEVAL1Z

• Rohs: yes
• Product: Evaluation Board
• Tool Is For Evaluation Of: ISL55210
• Operating Supply Voltage: 3.3 V
• Description/function: Evaluation board to test the performance of the active balun
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Operating Supply Current: 34 mA
• For Use With: ISL55210

Measured Performance On The Active Balun
Board
Taking the default configuration of Figure 1 implemented as the
top output interface of Figure 4 and measuring the S21 response
from 1MHz to 2GHz gives the exceptionally flat response of
Figure 6. Two different sets of blocking caps where used here
where the increase from 1nF to 10nF moved the high pass corner
down with no adverse self resonance at higher frequencies. Even
with the 10nF caps, part of the high pass corner is being set by
the MABA- 007871 where the true low end corner to the FDA
outputs is shown in the green curve. The high frequency rolloff
follows the simulation of Figure 3 up through about 600MHz then
a slight peaking in the ISL55210 response is pulling it back up.
This is showing a 10.2dB midband gain to a matched load (the
two series output resistors set the output impedance since the
ISL55210 is a broadband low impedance output itself) with ≤1dB
gain rolloff from 3MHz to 1GHz. Figure 6 also shows the response
to the differential output using a 4 port network analyzer and two
50Ω series output element of the lowest output interface option
in Figure 4. This gives more insertion loss but does show the
ISL55210 by itself is peaking to the output above 900MHz at this
lower gain, so the rolloff with the transformer output is actually
the transformer itself.
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FIGURE 5. POPULATED BOARD AS DELIVERED FROM INTERSIL
Application Note 1831
The two upper curves of Figure 6 through the transmission line
transformer are emulating the available response at this gain
with some added rolloff due to the transformer. These are giving
a 50Ω single ended input to differential output stage that is
delivering the equivalent of a 1:3.3 turns ratio step up in gain
with a flatness span far exceeding any balun of that turns ratio
(1:11Ω ratio).
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0
100k
FIGURE 6. MEASURED RESPONSE SHAPES
BLOCKING CAPS = 10nF
1M
FREQUENCY (Hz)
DIRECT OUTPUT TO ANALYZER
10M
BLOCKING CAPS = 1nF
100M
April 5, 2013
AN1831.0
1G