Texas Instruments THS4012 - Manual (Page 16)

THS4012 EVM Differential Input
1-10 General
1.7 THS4012 EVM Differential Input
The THS4012 EVM is shipped preconfigured for dual-channel, single-ended
noninverting operation. It can be reconfigured for single-channel, differential
operation, either noninverting or inverting.
1.7.1 Differential Input, Noninverting Operation
Configure the THS4012 EVM for differential noninverting operation by
removing two resistors and adding a resistor on the board:
1) Remove resistors R1 and R9.
2) Add a 100-
Ω
resistor to the R8 location on the board.
This configuration (noninverting) is shown in Figure 1–4. For a noninverting
differential input, R8 should be 100
Ω
to match 50-
Ω
source impedances. Note
that compensation capacitors C3 and C6 are not installed.
Figure 1–4. THS4012 EVM Schematic — Differential Input (Noninverting Operation)
C1
6.8 µ F
–VCC
1
GND
2
+VCC
3
J2
C2
6.8 µ F
–VCC
+VCC
–
+
U1:A
THS4012
1
4
8 2
3
R3
0
Ω
R6
1 k Ω
+VCC
C3
x µ F
R7
49.9
Ω
Vout1
J3
C4
0.1
µ
F
–VCC
J1
Vin1
R8
100 Ω
–
+
U1:B
THS4012
7
6
5
R11
0
Ω
R14
1 k Ω
C6
x
µ
F
R15
49.9 Ω
Vout2
J5
J4
Vin2
C5
0.1 µ F
R5
1 k Ω
R13
1 k Ω