Texas Instruments MSP430x4xx - Manual (Page 314)

OA
16-7 OA
Figure 16−2 shows an example of a two-opamp differential amplifier using
OA0 and OA1. The control register settings and are shown in Table 16−2. The
gain for the amplifier is selected by the OAFBRx bits for OA1 and is shown in
Table 16−3. The OAx interconnections are shown in Figure 16−3.
Table 16−2.Two-Opamp Differential Amplifier Control Register Settings
Register Settings (binary)
OA0CTL0 00 xx xx 0 0
OA0CTL1 000 111 0 x
OA1CTL0 10 xx xx x x
OA1CTL1 xxx 110 0 x
Table 16−3.Two-Opamp Differential Amplifier Gain Settings
OA1 OAFBRx Gain
000 0
001 1/3
010 1
011 1 2/3
100 3
101 4 1/3
110 7
111 15
Figure 16−2. Two Opamp Differential Amplifier
OA0
+
−
OA1
+
−
1
2 ) 1 2 (
R
xR V V
Vdiff
−
=
R2 R1
V2
V1