+Vcc2
-Vcc1
GND
GND
+Vcc1
+Vcc2
TP4
DNP
GND
Junc Vocm
GND
GND
-Vcc2
-Vcc1
GND
GND
GND
Vin+
Vin-
VBuf_In
D2S_Out
TP5
DNP
+V_In
-V_In
TP7
DNP
CM_In
TP8
DNP
Vmid_In
TP14
DNP
D2S_Out
GND
0.22
µ
F
C15
DNP
0.22
µ
F
C16
DNP
0.22
µ
F
C19
DNP
0.22
µ
F
C22
0.22
µ
F
C24
49.9
R3
49.9
R4
49.9
R33
49.9
R63
49.9
R16
DNP
10.0k
R8
10.0k
R7
10.0k
R17
10.0k
R5
DNP
10.0k
R6
DNP
10.0
R9
10.0
R10
10.0
R11
1.00k
R13
1.00k
R15
1k
R14
DNP
73.2
R21
0
R22
0
R27
DNP
20k
R24
169
R25
0.01
µ
F
C23
DNP
2.2pF
C26
DNP
11pF
C27
DNP
1.00
R23
DNP
4.02k
R62
DNP
DISABLE
10
GND
7
+IN
2
-IN
3
PAD
17
PATHSEL
4
VIN-
12
+VCC2
16
+VCC1
13
-VCC1
8
-VCC2
5
VIN+
9
VMID_IN
1
VMID_OUT
15
VO1
6
VOUT
11
VREF
14
U1
THS3215IRGVR
Or
THS3217IRGVR
72nH
L8
DNP
0
R1
0
R2
0
R18
0
R19
0
R12
1
2
3
4
5
J3
1
2
3
4
5
J1
1
2
3
4
5
J2
1
2
3
4
5
J5
Uninstall all the RLC filter components if
not used in the application to prevent
loading the D2S output
Design Considerations
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SBOU161A – February 2016 – Revised April 2016
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Copyright © 2016, Texas Instruments Incorporated
THS3215EVM and THS3217EVM
2.4
Differential to Single-Ended Stage (D2S)
The D2S inputs are driven by an external differential signal through SMA connectors J1 and J2. Standard
lab equipment usually provides only a single-ended output. The
LMH3401
, a very wideband, single-ended
to differential amplifier, was used during product evaluation to drive a differential signal into the D2S. The
spacing of the SMA connectors on the THS321xEVM is designed to interface directly with the output of
the
LMH3401EVM
through standard SMA barrel connectors. The THS321xEVM provides a standard 100-
Ω
differentially-terminated resistive network to GND, dc-coupled to the D2S input pins.
Figure 4
shows the
EVM schematic of the D2S input/output network with the default passive components installed. The output
of the D2S can also be measured externally at J5.
Figure 4. D2S Input Connection Options
