OPAMP
EMLIB

Detailed Description

Operational Amplifier (OPAMP) peripheral API.

This module contains functions to:

All OPAMP functions assume that the DAC clock is running. If DAC is not used, the clock can be turned off when OPAMPs are configured.

If the available gain values don't suit the application at hand, the resistor ladders can be disabled and external gain programming resistors used.

A number of predefined OPAMP setup macros are available for configuration of the most common OPAMP topologies (see figures below).

Note
The terms POSPAD and NEGPAD in the figures are used to indicate that these pads should be connected to a suitable signal ground.


Unity gain voltage follower.
Use predefined macros OPA_INIT_UNITY_GAIN and OPA_INIT_UNITY_GAIN_OPA2 . 

                    |\
         ___________|+\
                    |  \_______
                 ___|_ /    |
                |   | /     |
                |   |/      |
                |___________|


Non-inverting amplifier.
Use predefined macros OPA_INIT_NON_INVERTING and OPA_INIT_NON_INVERTING_OPA2 . 

                    |\
         ___________|+\
                    |  \_______
                 ___|_ /    |
                |   | /     |
                |   |/      |
                |_____R2____|
                |
                R1
                |
              NEGPAD


Inverting amplifier.
Use predefined macros OPA_INIT_INVERTING and OPA_INIT_INVERTING_OPA2 . 

                 _____R2____
                |           |
                |   |\      |
         ____R1_|___|_\     |
                    |  \____|___
                 ___|  /
                |   |+/
                |   |/
                |
              POSPAD


Cascaded non-inverting amplifiers.
Use predefined macros OPA_INIT_CASCADED_NON_INVERTING_OPA0 , OPA_INIT_CASCADED_NON_INVERTING_OPA1 and OPA_INIT_CASCADED_NON_INVERTING_OPA2 . 

                    |\                       |\                       |\
         ___________|+\ OPA0      ___________|+\ OPA1      ___________|+\ OPA2
                    |  \_________|           |  \_________|           |  \_______
                 ___|_ /    |             ___|_ /    |             ___|_ /    |
                |   | /     |            |   | /     |            |   | /     |
                |   |/      |            |   |/      |            |   |/      |
                |_____R2____|            |_____R2____|            |_____R2____|
                |                        |                        |
                R1                       R1                       R1
                |                        |                        |
              NEGPAD                   NEGPAD                   NEGPAD


Cascaded inverting amplifiers.
Use predefined macros OPA_INIT_CASCADED_INVERTING_OPA0 , OPA_INIT_CASCADED_INVERTING_OPA1 and OPA_INIT_CASCADED_INVERTING_OPA2 . 

                 _____R2____              _____R2____              _____R2____
                |           |            |           |            |           |
                |   |\      |            |   |\      |            |   |\      |
         ____R1_|___|_\     |     ____R1_|___|_\     |     ____R1_|___|_\     |
                    |  \____|____|           |  \____|___|            |  \____|__
                 ___|  /                  ___|  /                  ___|  /
                |   |+/ OPA0             |   |+/ OPA1             |   |+/ OPA2
                |   |/                   |   |/                   |   |/
                |                        |                        |
              POSPAD                   POSPAD                   POSPAD


Differential driver with two opamp's.
Use predefined macros OPA_INIT_DIFF_DRIVER_OPA0 and OPA_INIT_DIFF_DRIVER_OPA1 . 

                                  __________________________
                                 |                          +
                                 |        _____R2____
                    |\           |       |           |
         ___________|+\ OPA0     |       |   |\ OPA1 |
                    |  \_________|____R1_|___|_\     |      _
                 ___|_ /         |           |  \____|______
                |   | /          |        ___|  /
                |   |/           |       |   |+/
                |________________|       |   |/
                                         |
                                       POSPAD


Differential receiver with three opamp's.
Use predefined macros OPA_INIT_DIFF_RECEIVER_OPA0 , OPA_INIT_DIFF_RECEIVER_OPA1 and OPA_INIT_DIFF_RECEIVER_OPA2 . 

                    |\
          __________|+\ OPA1
         _          |  \_________
                 ___|_ /    |    |        _____R2____
                |   | /     |    |       |           |
                |   |/      |    |       |   |\      |
                |___________|    |____R1_|___|_\     |
                                             |  \____|___
                    |\            ____R1_ ___|  /
         +__________|+\ OPA0     |       |   |+/ OPA2
                    |  \_________|       |   |/
                 ___|_ /    |            R2
                |   | /     |            |
                |   |/      |          NEGPAD OPA0
                |___________|

Data Structures

struct OPAMP_Init_TypeDef

Macros

#define OPA_INIT_CASCADED_INVERTING_OPA0
#define OPA_INIT_CASCADED_INVERTING_OPA1
#define OPA_INIT_CASCADED_INVERTING_OPA2
#define OPA_INIT_CASCADED_NON_INVERTING_OPA0
#define OPA_INIT_CASCADED_NON_INVERTING_OPA1
#define OPA_INIT_CASCADED_NON_INVERTING_OPA2
#define OPA_INIT_DIFF_DRIVER_OPA0
#define OPA_INIT_DIFF_DRIVER_OPA1
#define OPA_INIT_DIFF_RECEIVER_OPA0
#define OPA_INIT_DIFF_RECEIVER_OPA1
#define OPA_INIT_DIFF_RECEIVER_OPA2
#define OPA_INIT_INVERTING
#define OPA_INIT_INVERTING_OPA2
#define OPA_INIT_NON_INVERTING
#define OPA_INIT_NON_INVERTING_OPA2
#define OPA_INIT_UNITY_GAIN
#define OPA_INIT_UNITY_GAIN_OPA2

Enumerations

enum OPAMP_NegSel_TypeDef {
opaNegSelDisable = DAC_OPA0MUX_NEGSEL_DISABLE,
opaNegSelUnityGain = DAC_OPA0MUX_NEGSEL_UG,
opaNegSelResTap = DAC_OPA0MUX_NEGSEL_OPATAP,
opaNegSelNegPad = DAC_OPA0MUX_NEGSEL_NEGPAD
}
enum OPAMP_OutMode_TypeDef {
opaOutModeDisable = DAC_OPA0MUX_OUTMODE_DISABLE,
opaOutModeMain = DAC_OPA0MUX_OUTMODE_MAIN,
opaOutModeAlt = DAC_OPA0MUX_OUTMODE_ALT,
opaOutModeAll = DAC_OPA0MUX_OUTMODE_ALL
}
enum OPAMP_PosSel_TypeDef {
opaPosSelDisable = DAC_OPA0MUX_POSSEL_DISABLE,
opaPosSelDac = DAC_OPA0MUX_POSSEL_DAC,
opaPosSelPosPad = DAC_OPA0MUX_POSSEL_POSPAD,
opaPosSelOpaIn = DAC_OPA0MUX_POSSEL_OPA0INP,
opaPosSelResTapOpa0 = DAC_OPA0MUX_POSSEL_OPATAP
}
enum OPAMP_ResInMux_TypeDef {
opaResInMuxDisable = DAC_OPA0MUX_RESINMUX_DISABLE,
opaResInMuxOpaIn = DAC_OPA0MUX_RESINMUX_OPA0INP,
opaResInMuxNegPad = DAC_OPA0MUX_RESINMUX_NEGPAD,
opaResInMuxPosPad = DAC_OPA0MUX_RESINMUX_POSPAD,
opaResInMuxVss = DAC_OPA0MUX_RESINMUX_VSS
}
enum OPAMP_ResSel_TypeDef {
opaResSelDefault = DAC_OPA0MUX_RESSEL_DEFAULT,
opaResSelR2eq0_33R1 = DAC_OPA0MUX_RESSEL_RES0,
opaResSelR2eqR1 = DAC_OPA0MUX_RESSEL_RES1,
opaResSelR1eq1_67R1 = DAC_OPA0MUX_RESSEL_RES2,
opaResSelR2eq2R1 = DAC_OPA0MUX_RESSEL_RES3,
opaResSelR2eq3R1 = DAC_OPA0MUX_RESSEL_RES4,
opaResSelR2eq4_33R1 = DAC_OPA0MUX_RESSEL_RES5,
opaResSelR2eq7R1 = DAC_OPA0MUX_RESSEL_RES6,
opaResSelR2eq15R1 = DAC_OPA0MUX_RESSEL_RES7
}
enum OPAMP_TypeDef {
OPA0 = 0,
OPA1 = 1,
OPA2 = 2
}

Functions

void OPAMP_Disable (DAC_TypeDef *dac, OPAMP_TypeDef opa)
Disable an Operational Amplifier.
void OPAMP_Enable (DAC_TypeDef *dac, OPAMP_TypeDef opa, const OPAMP_Init_TypeDef *init)
Configure and enable an Operational Amplifier.

Macro Definition Documentation

#define OPA_INIT_CASCADED_INVERTING_OPA0
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeAll, /* Both main and alternate outputs. */ \
opaResSelR2eqR1, /* R2 = R1 */ \
opaResInMuxNegPad, /* Resistor ladder input from negative pad. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
true, /* Pass output to next stage (OPA1). */ \
true, /* Negative pad enabled, used as signal input. */ \
true, /* Positive pad enabled, used as signal ground. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA0 in cascaded inverting amplifier mode.

Definition at line 728 of file em_opamp.h .

#define OPA_INIT_CASCADED_INVERTING_OPA1
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeAll, /* Both main and alternate outputs. */ \
opaResSelR2eqR1, /* R2 = R1 */ \
opaResInMuxOpaIn, /* Resistor ladder input from OPA0. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
true, /* Pass output to next stage (OPA2). */ \
false, /* Negative pad disabled. */ \
true, /* Positive pad enabled, used as signal ground. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA1 in cascaded inverting amplifier mode.

Definition at line 750 of file em_opamp.h .

#define OPA_INIT_CASCADED_INVERTING_OPA2
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelR2eqR1, /* R2 = R1 */ \
opaResInMuxOpaIn, /* Resistor ladder input from OPA1. */ \
DAC_OPA0MUX_OUTPEN_OUT0, /* Alternate output 0 enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
false, /* Negative pad disabled. */ \
true, /* Positive pad enabled, used as signal ground. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA2 in cascaded inverting amplifier mode.

Definition at line 772 of file em_opamp.h .

#define OPA_INIT_CASCADED_NON_INVERTING_OPA0
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeAll, /* Both main and alternate outputs. */ \
opaResSelR2eq0_33R1, /* R2 = 1/3 R1 */ \
opaResInMuxNegPad, /* Resistor ladder input from negative pad. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
true, /* Pass output to next stage (OPA1). */ \
true, /* Negative pad enabled, used as signal ground. */ \
true, /* Positive pad enabled, used as signal input. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA0 in cascaded non-inverting amplifier mode.

Definition at line 662 of file em_opamp.h .

#define OPA_INIT_CASCADED_NON_INVERTING_OPA1
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelOpaIn, /* Positive input from OPA0 output. */ \
opaOutModeAll, /* Both main and alternate outputs. */ \
opaResSelR2eq0_33R1, /* R2 = 1/3 R1 */ \
opaResInMuxNegPad, /* Resistor ladder input from negative pad. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
true, /* Pass output to next stage (OPA2). */ \
true, /* Negative pad enabled, used as signal ground. */ \
false, /* Positive pad disabled. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA1 in cascaded non-inverting amplifier mode.

Definition at line 684 of file em_opamp.h .

#define OPA_INIT_CASCADED_NON_INVERTING_OPA2
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelOpaIn, /* Positive input from OPA1 output. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelR2eq0_33R1, /* R2 = 1/3 R1 */ \
opaResInMuxNegPad, /* Resistor ladder input from negative pad. */ \
DAC_OPA0MUX_OUTPEN_OUT0, /* Alternate output 0 enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
true, /* Negative pad enabled, used as signal ground. */ \
false, /* Positive pad disabled. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA2 in cascaded non-inverting amplifier mode.

Definition at line 706 of file em_opamp.h .

#define OPA_INIT_DIFF_DRIVER_OPA0
Value:
{ \
opaNegSelUnityGain, /* Unity gain. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeAll, /* Both main and alternate outputs. */ \
opaResSelDefault, /* Resistor ladder is not used. */ \
opaResInMuxDisable, /* Resistor ladder disabled. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
true, /* Pass output to next stage (OPA1). */ \
false, /* Negative pad disabled. */ \
true, /* Positive pad enabled, used as signal input. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA0 in two-opamp differential driver mode.

Definition at line 794 of file em_opamp.h .

#define OPA_INIT_DIFF_DRIVER_OPA1
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelR2eqR1, /* R2 = R1 */ \
opaResInMuxOpaIn, /* Resistor ladder input from OPA0. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
false, /* Negative pad disabled. */ \
true, /* Positive pad enabled, used as signal ground. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA1 in two-opamp differential driver mode.

Definition at line 816 of file em_opamp.h .

#define OPA_INIT_DIFF_RECEIVER_OPA0
Value:
{ \
opaNegSelUnityGain, /* Unity gain. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeAll, /* Both main and alternate outputs. */ \
opaResSelR2eqR1, /* R2 = R1 */ \
opaResInMuxNegPad, /* Resistor ladder input from negative pad. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
true, /* Pass output to next stage (OPA2). */ \
true, /* Negative pad enabled, used as signal ground. */ \
true, /* Positive pad enabled, used as signal input. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA0 in three-opamp differential receiver mode.

Definition at line 838 of file em_opamp.h .

#define OPA_INIT_DIFF_RECEIVER_OPA1
Value:
{ \
opaNegSelUnityGain, /* Unity gain. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeAll, /* Both main and alternate outputs. */ \
opaResSelDefault, /* Resistor ladder is not used. */ \
opaResInMuxDisable, /* Disable resistor ladder. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
true, /* Pass output to next stage (OPA2). */ \
false, /* Negative pad disabled. */ \
true, /* Positive pad enabled, used as signal input. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA1 in three-opamp differential receiver mode.

Definition at line 860 of file em_opamp.h .

#define OPA_INIT_DIFF_RECEIVER_OPA2
Value:
{ \
opaNegSelResTap, /* Input from resistor ladder tap. */ \
opaPosSelResTapOpa0, /* Input from OPA0 resistor ladder tap. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelR2eqR1, /* R2 = R1 */ \
opaResInMuxOpaIn, /* Resistor ladder input from OPA1. */ \
DAC_OPA0MUX_OUTPEN_OUT0, /* Enable alternate output 0. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
false, /* Negative pad disabled. */ \
false, /* Positive pad disabled. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA2 in three-opamp differential receiver mode.

Definition at line 882 of file em_opamp.h .

#define OPA_INIT_INVERTING
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelR2eqR1, /* R2 = R1 */ \
opaResInMuxNegPad, /* Resistor ladder input from negative pad. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
true, /* Negative pad enabled, used as signal input. */ \
true, /* Positive pad enabled, used as signal ground. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA0/1 in inverting amplifier mode.

Definition at line 618 of file em_opamp.h .

#define OPA_INIT_INVERTING_OPA2
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelR2eqR1, /* R2 = R1 */ \
opaResInMuxNegPad, /* Resistor ladder input from negative pad. */ \
DAC_OPA0MUX_OUTPEN_OUT0, /* Alternate output 0 enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
true, /* Negative pad enabled, used as signal input. */ \
true, /* Positive pad enabled, used as signal ground. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA2 in inverting amplifier mode.

Definition at line 640 of file em_opamp.h .

#define OPA_INIT_NON_INVERTING
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelR2eq0_33R1, /* R2 = 1/3 R1 */ \
opaResInMuxNegPad, /* Resistor ladder input from negative pad. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
true, /* Negative pad enabled, used as signal ground. */ \
true, /* Positive pad enabled, used as signal input. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA0/1 in non-inverting amplifier mode.

Definition at line 574 of file em_opamp.h .

#define OPA_INIT_NON_INVERTING_OPA2
Value:
{ \
opaNegSelResTap, /* Negative input from resistor ladder tap. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelR2eq0_33R1, /* R2 = 1/3 R1 */ \
opaResInMuxNegPad, /* Resistor ladder input from negative pad. */ \
DAC_OPA0MUX_OUTPEN_OUT0, /* Alternate output 0 enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
true, /* Negative pad enabled, used as signal ground. */ \
true, /* Positive pad enabled, used as signal input. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA2 in non-inverting amplifier mode.

Definition at line 596 of file em_opamp.h .

#define OPA_INIT_UNITY_GAIN
Value:
{ \
opaNegSelUnityGain, /* Unity gain. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelDefault, /* Resistor ladder is not used. */ \
opaResInMuxDisable, /* Resistor ladder disabled. */ \
0, /* No alternate outputs enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
false, /* Negative pad disabled. */ \
true, /* Positive pad enabled, used as signal input. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA0/1 in unity gain voltage follower mode.

Definition at line 530 of file em_opamp.h .

#define OPA_INIT_UNITY_GAIN_OPA2
Value:
{ \
opaNegSelUnityGain, /* Unity gain. */ \
opaPosSelPosPad, /* Positive input from pad. */ \
opaOutModeMain, /* Main output enabled. */ \
opaResSelDefault, /* Resistor ladder is not used. */ \
opaResInMuxDisable, /* Resistor ladder disabled. */ \
DAC_OPA0MUX_OUTPEN_OUT0, /* Alternate output 0 enabled. */ \
_DAC_BIASPROG_BIASPROG_DEFAULT, /* Default bias setting. */ \
_DAC_BIASPROG_HALFBIAS_DEFAULT, /* Default half-bias setting. */ \
false, /* No low pass filter on positive pad. */ \
false, /* No low pass filter on negative pad. */ \
false, /* No nextout output enabled. */ \
false, /* Negative pad disabled. */ \
true, /* Positive pad enabled, used as signal input. */ \
false, /* No shorting of inputs. */ \
false, /* Rail-to-rail input enabled. */ \
true, /* Use factory calibrated opamp offset. */ \
0 /* Opamp offset value (not used). */ \
}

Configuration of OPA2 in unity gain voltage follower mode.

Definition at line 552 of file em_opamp.h .

Enumeration Type Documentation

enum OPAMP_NegSel_TypeDef

OPAMP negative terminal input selection values.

Enumerator
opaNegSelDisable

Input disabled.

opaNegSelUnityGain

Unity gain feedback path.

opaNegSelResTap

Feedback resistor ladder tap.

opaNegSelNegPad

Negative pad as input.

Definition at line 101 of file em_opamp.h .

enum OPAMP_OutMode_TypeDef

OPAMP output terminal selection values.

Enumerator
opaOutModeDisable

OPA output disabled.

opaOutModeMain

Main output to pin enabled.

opaOutModeAlt

Alternate output(s) enabled (not OPA2).

opaOutModeAll

Both main and alternate enabled (not OPA2).

Definition at line 261 of file em_opamp.h .

enum OPAMP_PosSel_TypeDef

OPAMP positive terminal input selection values.

Enumerator
opaPosSelDisable

Input disabled.

opaPosSelDac

DAC as input (not OPA2).

opaPosSelPosPad

Positive pad as input.

opaPosSelOpaIn

Input from OPAx.

opaPosSelResTapOpa0

Feedback resistor ladder tap from OPA0.

Definition at line 180 of file em_opamp.h .

enum OPAMP_ResInMux_TypeDef

OPAMP resistor ladder input selector values.

Enumerator
opaResInMuxDisable

Resistor ladder disabled.

opaResInMuxOpaIn

Input from OPAx.

opaResInMuxNegPad

Input from negative pad.

opaResInMuxPosPad

Input from positive pad.

opaResInMuxVss

Input connected to Vss.

Definition at line 365 of file em_opamp.h .

enum OPAMP_ResSel_TypeDef

OPAMP gain values.

Enumerator
opaResSelDefault

Default value when resistor ladder is unused.

opaResSelR2eq0_33R1

R2 = 0.33 * R1

opaResSelR2eqR1

R2 = R1

opaResSelR1eq1_67R1

R2 = 1.67 R1

opaResSelR2eq2R1

R2 = 2 * R1

opaResSelR2eq3R1

R2 = 3 * R1

opaResSelR2eq4_33R1

R2 = 4.33 * R1

opaResSelR2eq7R1

R2 = 7 * R1

opaResSelR2eq15R1

R2 = 15 * R1

Definition at line 340 of file em_opamp.h .

enum OPAMP_TypeDef

OPAMP selector values.

Enumerator
OPA0

Select OPA0.

OPA1

Select OPA1.

OPA2

Select OPA2.

Definition at line 85 of file em_opamp.h .

Function Documentation

void OPAMP_Disable ( DAC_TypeDef * dac,
OPAMP_TypeDef opa
)

Disable an Operational Amplifier.

Parameters
[in] dac A pointer to the DAC peripheral register block.
[in] opa Selects an OPA, valid values are OPA0 , OPA1 , and OPA2 .

Definition at line 258 of file em_opamp.c .

References OPA0 , OPA1 , and OPA2 .

Referenced by OPAMP_Enable() .

void OPAMP_Enable ( DAC_TypeDef * dac,
OPAMP_TypeDef opa,
const OPAMP_Init_TypeDef * init
)

Configure and enable an Operational Amplifier.

Note
The value of the alternate output enable bit mask in the OPAMP_Init_TypeDef structure should consist of one or more of the DAC_OPA[opa#]MUX_OUTPEN_OUT[output#] flags (defined in <part_name>_dac.h) OR'ed together.

For OPA0:
  • DAC_OPA0MUX_OUTPEN_OUT0
  • DAC_OPA0MUX_OUTPEN_OUT1
  • DAC_OPA0MUX_OUTPEN_OUT2
  • DAC_OPA0MUX_OUTPEN_OUT3
  • DAC_OPA0MUX_OUTPEN_OUT4
For OPA1:
  • DAC_OPA1MUX_OUTPEN_OUT0
  • DAC_OPA1MUX_OUTPEN_OUT1
  • DAC_OPA1MUX_OUTPEN_OUT2
  • DAC_OPA1MUX_OUTPEN_OUT3
  • DAC_OPA1MUX_OUTPEN_OUT4
For OPA2:
  • DAC_OPA2MUX_OUTPEN_OUT0
  • DAC_OPA2MUX_OUTPEN_OUT1
E.g:
init.outPen = DAC_OPA0MUX_OUTPEN_OUT0 | DAC_OPA0MUX_OUTPEN_OUT4;
Parameters
[in] dac A pointer to the DAC peripheral register block.
[in] opa Selects an OPA, valid values are OPA0 , OPA1 , and OPA2 .
[in] init A pointer to a structure containing OPAMP initialization information.

Definition at line 369 of file em_opamp.c .

References OPAMP_Init_TypeDef::bias , OPAMP_Init_TypeDef::defaultOffset , OPAMP_Init_TypeDef::halfBias , OPAMP_Init_TypeDef::hcmDisable , OPAMP_Init_TypeDef::lpfNegPadDisable , OPAMP_Init_TypeDef::lpfPosPadDisable , OPAMP_Init_TypeDef::negSel , OPAMP_Init_TypeDef::nextOut , OPAMP_Init_TypeDef::npEn , OPAMP_Init_TypeDef::offset , OPA0 , OPA1 , OPA2 , OPAMP_Disable() , opaNegSelResTap , OPAMP_Init_TypeDef::outMode , OPAMP_Init_TypeDef::outPen , OPAMP_Init_TypeDef::posSel , OPAMP_Init_TypeDef::ppEn , OPAMP_Init_TypeDef::resInMux , OPAMP_Init_TypeDef::resSel , OPAMP_Init_TypeDef::shortInputs , and SYSTEM_GetCalibrationValue() .