44.8.3 OPAMP Control x

Name: OPAMPCTRL
Offset: 0x04 + n*0x04 [n=0..2]
Reset: 0x00000000
Property: PAC Write-Protection

Bit 3130292827262524 
          
Access  
Reset  
Bit 2322212019181716 
 MUXNEG[3:0]MUXPOS[3:0] 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset 00000000 
Bit 15141312111098 
 POTMUX[2:0]RES1MUX[2:0]RES1ENRES2OUT 
Access R/WR/WR/WR/WR/WR/WR/WR/W 
Reset 00000000 
Bit 76543210 
 ONDEMANDRUNSTDBYRES2VCCBIAS[1:0]ANAOUTENABLE  
Access R/WR/WR/WR/WR/WR/WR/W 
Reset 0000000 

Bits 23:20 – MUXNEG[3:0] Negative Input Mux Selection

Selection on negative input for operational amplifier x.

Value OPAMPx Name Description
0x0 x=0,1,2 OAxNEG OPAMPx Negative Input
0x1 x=0,1,2 OAxTAP OPAMPx Resistor Ladder Taps
0x2 x=0,1,2 REFERENCE REFERENCE[DAC/REFBUF]
0x3 x=0,1,2 OAxOUT
0x4 x=0,1 Reserved
x=2 OA0NEG OPAMP0 Negative Input
0x5 x=0,1 Reserved
x=2 OA1NEG OPAMP1 Negative Input

Bits 19:16 – MUXPOS[3:0] Positive Input Mux Selection

Selection on positive input for operational amplifier x.

Value OPAMPx Name Description
0x0 x=0,1,2 OAxPOS OPAMPx Positive Input
0x1 x=0,1,2 OAxTAP OPAMPx Resistor Ladder Taps
0x2 x=0,1,2 REFERENCE REFERENCE[DAC/REFBUF]
0x3 x=0,1,2 GND Ground
0x4 x=0 Reserved
x=1 OA0OUT OPAMP0 output
x=2 OA1OUT OPAMP1 output
0x5 x=0,1 Reserved
x=2 OA0POS OPAMP0 Positive Input
0x6 x=0,1 Reserved
x=2 OA1POS OPAMP1 Positive Input
0x7 x=0,1 Reserved
x=2 OA0TAP OPAMP0 Resistor Ladder Taps
0x8 x=0,1 Reserved
x=2 RES3TAP

Bits 15:13 – POTMUX[2:0] Potentiometer selection

Resistor selection bits control a numeric potentiometer with eight fixed values.

Value R1 R2
0x0 14R 2R
0x1 12R 4R
0x2 8R 8R
0x3 6R 10R
0x4 4R 12R
0x5 3R 13R
0x6 2R 14R
0x7 R 15R

Bits 12:10 – RES1MUX[2:0] Resistor 1 Mux

These bits select the connection of R1 resistor of the potentiometer.

Value OPAMPx Name Description
0x0 x=0,1,2 OAxPOS OPAMPx Positive Input
0x1 x=0,1,2 OAxNEG OPAMPx Negative Input
0x2 x=0 REFERENCE REFERENCE[DAC/REFBUF]
x=1 OA0OUT OPAMP0 output
x=2 OA1OUT OPAMP1 output
0x3 x=0,1,2 GND
0x4 x=0,1 RG_CONN
x=2 Reserved

Bit 9 – RES1EN Resistor 1 Enable

ValueDescription
0 R1 disconnected from RES1MUX.
1 R1 connected to RES1MUX.

Bit 8 – RES2OUT Resistor ladder To Output

ValueDescription
0 Swith open.
1 Switch closed.

Bit 7 – ONDEMAND On Demand Control

The On Demand operation mode allows the OPAMPx to be enabled or disabled, depending on other peripheral requests.

ValueDescription
0 The OPAMPx is always on, if enabled.
1 The OPAMPx is enabled when a peripheral is requesting the OPAMPx to be used as an input. The OPAMPx is disabled if no peripheral is requesting it as an input.

Bit 6 – RUNSTDBY Run in Standby

This bit controls how the OPAMPx behaves during standby sleep mode:

ValueDescription
0 The OPAMPx is disabled in standby sleep mode.
1 The OPAMPx is not stopped in standby sleep mode. If OPAMPCTRLx.ONDEMAND=1, the OPAMPx will be running when a peripheral is requesting it as an input. If OPAMPCTRLx.ONDEMAND=0, OPAMPx will always be running in standby sleep mode.

Bit 5 – RES2VCC Resistor ladder To VCC

ValueDescription
0 Swith open.
1 Switch closed.

Bits 4:3 – BIAS[1:0] Bias Selection

These bits are used to select the bias mode.

ValueNameDescription
0x0 Mode 0 Minimum current consumption, but the slowest mode
0x1 Mode 1 Low current consumption, slow speed
0x2 Mode 2 High current consumption, fast speed
0x3 Mode 3 Maximum current consumption but the fastest mode

Bit 2 – ANAOUT Analog Output

This bit controls a switch connected to the OPAMP output.

ValueDescription
0 Switch open. No ADC or AC connection.
1 Switch closed. OPAMP output is connected to the ADC or AC input.

Bit 1 – ENABLE Operational Amplifier Enable

ValueDescription
0 The OPAMPx is disabled
1 The OPAMPx is enabled