36.4.2 OPAxCON1
Important: The OPAxCON1 register applies
only to 14/20-pin devices and is not used in 28/40-pin
devices.
| Name: | OPAxCON1 |
| Offset: | 0x090D,0x0913 |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| GSEL[2:0] | RESON | NSS[2:0] | |||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | ||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||
Bits 6:4 – GSEL[2:0] Operational Amplifier Gain Selection
| Value | Description | |||
|---|---|---|---|---|
| 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
| Value | Description |
|---|---|
| 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
| Value | Description |
|---|---|
111 | VSS |
110 | Reserved |
101 | Reserved |
100 | OPA2IN4- |
011 | OPAxIN3- |
010 | OPAxIN2- |
001 | OPAxIN1- |
000 | OPAxIN0- |