OPAMP: Operational Amplifier

Overview

The MCUXpresso SDK provides a peripheral driver for the OPAMP module of MCUXpresso SDK devices. OPAMP driver is created to help user to operate the OPAMP module. The APIs can use enable OPAMP module initialize it and de-initialize OPAMP module.

Function groups

The OPAMP driver supports operating the module as a operational amplifier.

Initialization and deinitialization

The OPAMP_Init() function will initialize the OPAMP and enable the clock for OPAMP. The OPAMP_Deinit() function will disable OPAMP module and shut down the bus clock of OPAMP.

OPAMP positive and negative port gain configuration

The OPAMP_DoPosGainConfig() function is used to set positive port gain. The OPAMP_DoNegGainConfig() function is used to set negative port gain.

OPAMP reference buffer

The OPAMP_EnableRefBuffer() is enable bias voltage input buffer.

OPAMP trigger mode

The OPAMP_EnableTriggerMode() is enable OPAMP trigger mode.

Typical use case

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/OPAMP/

Data Structures
struct	opamp_config_t
	OPAMP configuraion, including mode, internal reference voltage, positive gain, negative gain and so on. More...

Enumerations
enum	opamp_mode_t {   kOPAMP_LowNoiseMode = 0U,   kOPAMP_HighSpeedMode }
	The enumeration of OPAMP mode, including low noise mode and high speed mode. More...
enum	opamp_bias_current_trim_option_t {   kOPAMP_TrimOptionDefault = 0U,   kOPAMP_TrimOptionIncreaseCurrent,   kOPAMP_TrimOptionDecreaseCurrent,   kOPAMP_TrimOptionFurtherDecreaseCurrent }
	The enumeration of bias current trim option. More...
enum	opamp_internal_ref_voltage_t {   kOPAMP_IntRefVoltVddaDiv2 = 0U,   kOPAMP_IntRefVoltVdda3V,   kOPAMP_IntRefVoltVssa3V,   kOPAMP_IntRefVoltNotAllowed }
	The enumeration of internal reference voltage. More...
enum	opamp_positive_ref_voltage_t {   kOPAMP_PosRefVoltVrefh3 = 0U,   kOPAMP_PosRefVoltVrefh0 = 1U,   kOPAMP_PosRefVoltVrefh1 = 2U,   kOPAMP_PosRefVoltVrefh4 = 3U }
	The enumeration of positive reference voltage（please refer to manual use）. More...
enum	opamp_positive_gain_t {   kOPAMP_PosGainReserved = 0U,   kOPAMP_PosGainNonInvert1X = 1U,   kOPAMP_PosGainNonInvert2X = 2U,   kOPAMP_PosGainNonInvert4X = 3U,   kOPAMP_PosGainNonInvert8X = 4U,   kOPAMP_PosGainNonInvert16X = 5U,   kOPAMP_PosGainNonInvert33X = 6U,   kOPAMP_PosGainNonInvert64X = 7U,   kOPAMP_PosGainNonInvertDisableBuffer2X = 8U,   kOPAMP_PosGainNonInvertDisableBuffer3X = 9U,   kOPAMP_PosGainNonInvertDisableBuffer5X = 10U,   kOPAMP_PosGainNonInvertDisableBuffer9X = 11U,   kOPAMP_PosGainNonInvertDisableBuffer17X = 12U,   kOPAMP_PosGainNonInvertDisableBuffer34X = 13U,   kOPAMP_PosGainNonInvertDisableBuffer65X = 14U }
	The enumeration of positive programmable gain (please refer to manual use). More...
enum	opamp_negative_gain_t {   kOPAMP_NegGainBufferMode = 0U,   kOPAMP_NegGainInvert1X,   kOPAMP_NegGainInvert2X,   kOPAMP_NegGainInvert4X,   kOPAMP_NegGainInvert8X,   kOPAMP_NegGainInvert16X,   kOPAMP_NegGainInvert33X,   kOPAMP_NegGainInvert64X }
	The enumeration of negative programmable gain. More...
enum	opamp_positive_input_channel_selection_t {   kOPAMP_PosInputChannel0 = 0U,   kOPAMP_PosInputChannel1 = 1U }
	The enumeration of positive input channel selection. More...

Driver version
#define	FSL_OPAMP_DRIVER_VERSION   (MAKE_VERSION(2, 2, 0))
	OPAMP driver version. More...

Initialization and deinitialization
void	OPAMP_Init (OPAMP_Type *base, const opamp_config_t *config)
	Initialize OPAMP instance. More...
void	OPAMP_Deinit (OPAMP_Type *base)
	De-initialize OPAMP instance. More...
void	OPAMP_GetDefaultConfig (opamp_config_t *config)
	Get default configuration of OPAMP. More...

Positive port gain and negative gain configuration.
static void	OPAMP_DoPosGainConfig (OPAMP_Type *base, opamp_positive_gain_t option)
	Configure OPAMP positive port gain. More...
static void	OPAMP_DoNegGainConfig (OPAMP_Type *base, opamp_negative_gain_t option)
	Configure OPAMP negative port gain. More...

Reference Buffer Control Interface
static void	OPAMP_EnableRefBuffer (OPAMP_Type *base, bool enable)
	Enable reference buffer. More...

Trigger Mode Control Interface
static void	OPAMP_EnableTriggerMode (OPAMP_Type *base, bool enable)
	Enable OPAMP trigger mode. More...

---

Data Structure Documentation

struct opamp_config_t

Data Fields
bool	enable
	Enable/disable OPAMP. More...
opamp_mode_t	mode
	Opamp mode, available values are kOPAMP_LowNoiseMode and kOPAMP_HighSpeedMode. More...
opamp_bias_current_trim_option_t	trimOption
	Bias current trim option, please refer to opamp_bias_current_trim_option_t. More...
opamp_internal_ref_voltage_t	intRefVoltage
	Internal reference voltage, please refer to opamp_internal_ref_voltage_t. More...
opamp_positive_ref_voltage_t	posRefVoltage
	Positive part reference voltage, please refer to opamp_positive_ref_voltage_t. More...
opamp_positive_gain_t	posGain
	Positive part programmable gain, please refer to opamp_positive_gain_t. More...
opamp_negative_gain_t	negGain
	Negative part programmable gain, please refer to opamp_negative_gain_t. More...
bool	enableOutputSwitch
	OPAMP out to negative gain resistor ladder switch. More...
bool	enablePosADCSw1
	Positive part reference voltage switch to ADC channel or not. More...
bool	enablePosADCSw2
	Positive part reference voltage switch to ADC channel or not. More...
bool	enableRefBuffer
	Reference buffer enable. More...
opamp_positive_input_channel_selection_t	PosInputChannelSelection
	Positive Input Channel Selection.
bool	enableTriggerMode
	Trigger Mode Enable. More...

Field Documentation

bool opamp_config_t::enable

opamp_mode_t opamp_config_t::mode

opamp_bias_current_trim_option_t opamp_config_t::trimOption

opamp_internal_ref_voltage_t opamp_config_t::intRefVoltage

opamp_positive_ref_voltage_t opamp_config_t::posRefVoltage

opamp_positive_gain_t opamp_config_t::posGain

opamp_negative_gain_t opamp_config_t::negGain

bool opamp_config_t::enableOutputSwitch

bool opamp_config_t::enablePosADCSw1

• true Positive part reference voltage switch to ADC channel.
• false Positive part reference voltage do not switch to ADC channel.

bool opamp_config_t::enablePosADCSw2

• true Positive part reference voltage switch to ADC channel.
• false Positive part reference voltage do not switch to ADC channel.

bool opamp_config_t::enableRefBuffer

bool opamp_config_t::enableTriggerMode

Macro Definition Documentation

#define FSL_OPAMP_DRIVER_VERSION   (MAKE_VERSION(2, 2, 0))

Enumeration Type Documentation

enum opamp_mode_t

Enumerator
kOPAMP_LowNoiseMode	Set opamp mode as low noise mode.
kOPAMP_HighSpeedMode	Set opamp mode as high speed mode.

enum opamp_bias_current_trim_option_t

Enumerator
kOPAMP_TrimOptionDefault	Default Bias current trim option.
kOPAMP_TrimOptionIncreaseCurrent	Trim option selected as increase current.
kOPAMP_TrimOptionDecreaseCurrent	Trim option selected as decrease current.
kOPAMP_TrimOptionFurtherDecreaseCurrent	Trim option selected as further decrease current.

enum opamp_internal_ref_voltage_t

Enumerator
kOPAMP_IntRefVoltVddaDiv2	Internal reference voltage selected as Vdda/2.
kOPAMP_IntRefVoltVdda3V	Internal reference voltage selected as Vdda_3V.
kOPAMP_IntRefVoltVssa3V	Internal reference voltage selected as Vssa_3V.
kOPAMP_IntRefVoltNotAllowed	Internal reference voltage not allowed.

enum opamp_positive_ref_voltage_t

Enumerator
kOPAMP_PosRefVoltVrefh3	Positive part reference voltage select Vrefh3, connected from DAC output.
kOPAMP_PosRefVoltVrefh0	Positive part reference voltage select Vrefh0, connected from VDDA supply.
kOPAMP_PosRefVoltVrefh1	Positive part reference voltage select Vrefh1, connected from Voltage reference output.
kOPAMP_PosRefVoltVrefh4	Positive part reference voltage select 520mv or reserved.

enum opamp_positive_gain_t

Enumerator
kOPAMP_PosGainReserved	Positive Gain reserved.
kOPAMP_PosGainNonInvert1X	Positive non-inverting gain application 1X.
kOPAMP_PosGainNonInvert2X	Positive non-inverting gain application 2X.
kOPAMP_PosGainNonInvert4X	Positive non-inverting gain application 4X.
kOPAMP_PosGainNonInvert8X	Positive non-inverting gain application 8X.
kOPAMP_PosGainNonInvert16X	Positive non-inverting gain application 16X.
kOPAMP_PosGainNonInvert33X	Positive non-inverting gain application 33X.
kOPAMP_PosGainNonInvert64X	Positive non-inverting gain application 64X.
kOPAMP_PosGainNonInvertDisableBuffer2X	Positive non-inverting gain application 2X.
kOPAMP_PosGainNonInvertDisableBuffer3X	Positive non-inverting gain application 3X.
kOPAMP_PosGainNonInvertDisableBuffer5X	Positive non-inverting gain application 5X.
kOPAMP_PosGainNonInvertDisableBuffer9X	Positive non-inverting gain application 9X.
kOPAMP_PosGainNonInvertDisableBuffer17X	Positive non-inverting gain application 17X.
kOPAMP_PosGainNonInvertDisableBuffer34X	Positive non-inverting gain application 34X.
kOPAMP_PosGainNonInvertDisableBuffer65X	Positive non-inverting gain application 65X.

enum opamp_negative_gain_t

Enumerator
kOPAMP_NegGainBufferMode	Negative Buffer Mode.
kOPAMP_NegGainInvert1X	Negative inverting gain application -1X.
kOPAMP_NegGainInvert2X	Negative inverting gain application -2X.
kOPAMP_NegGainInvert4X	Negative inverting gain application -4X.
kOPAMP_NegGainInvert8X	Negative inverting gain application -8X.
kOPAMP_NegGainInvert16X	Negative inverting gain application -16X.
kOPAMP_NegGainInvert33X	Negative inverting gain application -33X.
kOPAMP_NegGainInvert64X	Negative inverting gain application -64X.

enum opamp_positive_input_channel_selection_t

Enumerator
kOPAMP_PosInputChannel0	When OPAMP not in trigger mode, select positive input 0 (INP0).
kOPAMP_PosInputChannel1	When OPAMP not in trigger mode, select positive input 1 (INP1).

Function Documentation

void OPAMP_Init	(	OPAMP_Type *	base,
		const opamp_config_t *	config
	)

Parameters

base	OPAMP peripheral base address.
config	The pointer to opamp_config_t.

void OPAMP_Deinit

(

OPAMP_Type *

base

)

Parameters

base	OPAMP peripheral base address.

void OPAMP_GetDefaultConfig

(

opamp_config_t *

config

)

*     config->enable        = false;
*     config->mode          = kOPAMP_LowNoiseMode;
*     config->trimOption    = kOPAMP_TrimOptionDefault;
*     config->intRefVoltage = kOPAMP_IntRefVoltVddaDiv2;
*     config->enablePosADCSw = false;
*     config->posRefVoltage = kOPAMP_PosRefVoltVrefh3;
*     config->posGain       = kOPAMP_PosGainReserved;
*     config->negGain       = kOPAMP_NegGainBufferMode;
* 

Parameters

config

The pointer to opamp_config_t.

static void OPAMP_DoPosGainConfig ( OPAMP_Type *  base, opamp_positive_gain_t  option  )

inlinestatic

Parameters

base	OPAMP peripheral base address.
option	OPAMP positive port gain.

static void OPAMP_DoNegGainConfig ( OPAMP_Type *  base, opamp_negative_gain_t  option  )

inlinestatic

Parameters

base	OPAMP peripheral base address.
option	OPAMP negative port gain.

static void OPAMP_EnableRefBuffer ( OPAMP_Type *  base, bool  enable  )

inlinestatic

Parameters

base	OPAMP peripheral base address.
enable	true to enable and false to disable.

static void OPAMP_EnableTriggerMode ( OPAMP_Type *  base, bool  enable  )

inlinestatic

Parameters

base	OPAMP peripheral base address.
enable	true to enable and false to disable.