Texas Instruments THS4012 Musical Instrument Amplifier User Manual


 
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- 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 to match 50- 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 µF
–VCC
1
GND
2
+VCC
3
J2
C2
6.8 µF
–VCC
+VCC
+
U1:A
THS4012
1
4
8
2
3
R3
0
R6
1 k
+VCC
C3
x µF
R7
49.9
Vout1
J3
C4
0.1 µF
–VCC
J1
Vin1
R8
100
+
U1:B
THS4012
7
6
5
R11
0
R14
1 k
C6
x µF
R15
49.9
Vout2
J5
J4
Vin2
C5
0.1 µF
R5
1 k
R13
1 k