OPAxCON1

Operational Amplifier Control Register 1
Name:
OPAxCON1
Offset:
0x090D
Reset:
Access:
Bit76543210
GSEL[2:0]RESONNSS[2:0]
AccessR/WR/WR/WR/WR/WR/WR/W
Reset0000000

Bits 6:4 – GSEL[2:0]: Operational Amplifier Gain Selection

Operational Amplifier Gain Selection

Table 1. Operational Amplifier Internal Resistor Ladder Selections
GSEL[2:0] R1 R2 Inverting (R2/R1) Noninverting (1 + R2/R1)
111 1R 15R 15 16
110 2R 14R 7 8
101 4R 12R 3 4
100 6R 10R 5/3 8/3
011 8R 8R 1 2
010 12R 4R 1/3 4/3
001 14R 2R 1/7 8/7
000 15R 1R 1/15 16/15
Note: R = 20 kΩ nominal

Bit 3 – RESON: Resistor Ladder Enable

Resistor Ladder Enable

ValueDescription
1 Internal Resistor Ladder is enabled; OPA input is connected to the resistor ladder allowing GSEL to be used to control programmable gain.
0 Internal Resistor Ladder is disabled. External feedback to the OPA is required unless operating in Unity Gain mode.

Bits 2:0 – NSS[2:0]: Negative Source Selection

Negative Source Selection

Value Description
111 VSS
110 Reserved
101 Reserved
100 Reserved
011 OPAxIN3-
010 OPAxIN2-
001 OPAxIN1-
000 OPAxIN0-