National Semiconductor TSW3070EVM, Руководство пользователя

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A
Unit dBm
Ref Lvl
0 dBm
Ref Lvl
0 dBm
RF Att 30 dB
Start 1 MHz Stop 400 MHz 39.9 MHz/
RBW 30 kHz
VBW 30 kHz
SWT 1.15 s
1AP
2AP 2AP
3AP 3AP
4AP
1VIEW
2VIEW 2VIEW
3VIEW 3VIEW
4AP
-90
-80
-70
-60
-50
-40
-30
-20
-10
-100
0
Date: 28.MAR.2008 11:54:59
A
Unit dBm
RBW 20 kHz
VBW 20 kHz
SWT 1.25 s
Start 1 MHz Stop 200 MHz 19.9 MHz/
Ref Lvl
0 dBm
Ref Lvl
0 dBm
RF Att 50 dB
1AP
2AP 2AP
3AP
1VIEW
2VIEW 2VIEW
3VIEW 3VIEW 3AP
-90
-80
-70
-60
-50
-40
-30
-20
-10
-100
0
1
1 2
Marker 1 [T1]
-16.14 dBm
5.07815631 MHz
1 [T1] -16.14 dBm
5.07815631 MHz
1 [T1] -34.61 dB
5.10000000 MHz
2 [T1] -35.25 dB
10.26813627 MHz
Date: 25.APR.2008 12:50:56
Demonstration Kit Test Configuration Test Equipment 7.1 Test
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20 SLWU055A – May 2008 – Revised May 2016
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TSW3070EVM: Amplifier Interface to Current Sink DAC - Arbitrary Waveform
Generator Demonstration
A low-pass filter (LPF) is between the DAC outputs and the OPA695, THS3091, and THS3095. This
prevents any higher frequency DAC images from affecting performance of the amplifiers. The wide
bandwidth OPA695 is typically operated at lower gains with smaller output swings with a wider input LPF,
about 200 MHz. The THS3095 is normally operated at larger gains (larger feedback resistor) and larger
output swings which results in narrower output bandwidth. Consequently, the LPF for the THS3091 and
THS3095 is set lower at 100 MHz. Both LPFs are 50-
Ω differential, fifth-order Chebyshev filters with a 0.1-
dB ripple. Filter design can be done according to application report SLWA053
Figure 9. THS3091 and THS3095 LPF Filter Shape Evaluated With Multi-tone Input Signal From the
TSW3100 Pattern Generator
Figure 10. OPA695 LPF Filter Shape Evaluated With Multi-tone Signal