Datasheet

INP
INM
VCM
1:1
5 W
25 W
25 W
5 W
0.1 Fm
0.1 Fm
TF_ADC
S0256-01
ADS6xxx
INP
INM
VCM
1:1 1:1
5 W
50 W
50 W
50 W
50 W
5 W
0.1 Fm
0.1 Fm
S0164-04
ADS6xxx
ADS6445, ADS6444
ADS6443, ADS6442
www.ti.com SLAS531B –MAY 2007–REVISED DECEMBER 2009
Figure 85. Single Transformer Drive Circuit
At high input frequencies, the mismatch in the transformer parasitic capacitance (between the windings) results
in degraded even-order harmonic performance. Connecting two identical RF transformers back-to-back helps
minimize this mismatch, and good performance is obtained for high frequency input signals. Figure 86 shows an
example using two transformers (like Coilcraft WBC1-1). An additional termination resistor pair (enclosed within
the shaded box in Figure 86) may be required between the two transformers to improve the balance between the
P and M sides. The center point of this termination must be connected to ground.
Figure 86. Two Transformer Drive Circuit
Copyright © 2007–2009, Texas Instruments Incorporated Submit Documentation Feedback 51
Product Folder Link(s): ADS6445, ADS6444 ADS6443, ADS6442