This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the device's Operational Amplifier Controller functionality.

The following peripheral is used by this module:

OPAMP (Operational Amplifier Controller)

The following devices can use this module:

Atmel | SMART SAM L21

The outline of this documentation is as follows:

Prerequisites

There are no prerequisites for this module.

Module Overview

The OPAMP is an individually configurable low power, general purpose operational amplifier offering a high degree of flexibility and rail-to-rail inputs.

Each operational amplifier can be configured in standalone operational amplifier and operational amplifier with built-in feedback. All OPAMPs can be cascaded to support circuits such as differential amplifiers.

Note: For more detail configuration reference, refer to the "Built-in Modes" section in the device datasheet.

Each OPAMP has one positive and one negative input which can be flexible chosen from analog input pins including the output of another OPAMP, internal inputs such as the DAC or the resistor ladder, and the ground.

Each OPAMP output can be selected as input for AC or ADC, also available on I/O pins.

Four modes are available to select the trade-off between speed and power consumption to best fit the application requirements and optimize the power consumption.

Special Considerations

There are no special considerations for this module.

Extra Information

For extra information, see Extra Information for OPAMP Driver. This includes:

Examples

For a list of examples related to this driver, see Examples for OPAMP Driver.

API Overview

Modules
	Quick Start Guide(s)
	In this section you can find a list of all Quick Start guides related to the SAM Operational Amplifier Controller (OPAMP) Driver.

Data Structures
struct	opamp0_config
	OPAMP 0 configuration structure. More...

struct	opamp1_config
	OPAMP 1 configuration structure. More...

struct	opamp2_config
	OPAMP 2 configuration structure. More...

struct	opamp_config_common
	OPAMP 0 to 2 common configuration structure. More...

Enumerations
enum	opamp0_neg_mux { OPAMP0_NEG_MUX_PIN0 = OPAMP_OPAMPCTRL_MUXNEG(0), OPAMP0_NEG_MUX_TAP0 = OPAMP_OPAMPCTRL_MUXNEG(1), OPAMP0_NEG_MUX_OUT0 = OPAMP_OPAMPCTRL_MUXNEG(2), OPAMP0_NEG_MUX_DAC = OPAMP_OPAMPCTRL_MUXNEG(3) }
	Negative input MUX selection configuration enum. More...

enum	opamp0_pos_mux { OPAMP0_POS_MUX_PIN0 = OPAMP_OPAMPCTRL_MUXPOS(0), OPAMP0_POS_MUX_TAP0 = OPAMP_OPAMPCTRL_MUXPOS(1), OPAMP0_POS_MUX_DAC = OPAMP_OPAMPCTRL_MUXPOS(2), OPAMP0_POS_MUX_GND = OPAMP_OPAMPCTRL_MUXPOS(3) }
	Positive input MUX selection configuration enum. More...

enum	opamp0_res1_mux { OPAMP0_RES1_MUX_POS_PIN0 = OPAMP_OPAMPCTRL_RES1MUX(0), OPAMP0_RES1_MUX_NEG_PIN0 = OPAMP_OPAMPCTRL_RES1MUX(1), OPAMP0_RES1_MUX_DAC = OPAMP_OPAMPCTRL_RES1MUX(2), OPAMP0_RES1_MUX_GND = OPAMP_OPAMPCTRL_RES1MUX(3) }
	Resistor 1 MUX selection configuration enum. More...

enum	opamp1_neg_mux { OPAMP1_NEG_MUX_PIN1 = OPAMP_OPAMPCTRL_MUXNEG(0), OPAMP1_NEG_MUX_TAP1 = OPAMP_OPAMPCTRL_MUXNEG(1), OPAMP1_NEG_MUX_OUT1 = OPAMP_OPAMPCTRL_MUXNEG(2), OPAMP1_NEG_MUX_DAC = OPAMP_OPAMPCTRL_MUXNEG(3) }
	Negative input MUX selection configuration enum. More...

enum	opamp1_pos_mux { OPAMP1_POS_MUX_PIN1 = OPAMP_OPAMPCTRL_MUXPOS(0), OPAMP1_POS_MUX_TAP1 = OPAMP_OPAMPCTRL_MUXPOS(1), OPAMP1_POS_MUX_OUT0 = OPAMP_OPAMPCTRL_MUXPOS(2), OPAMP1_POS_MUX_GND = OPAMP_OPAMPCTRL_MUXPOS(3) }
	Positive input MUX selection configuration enum. More...

enum	opamp1_res1_mux { OPAMP1_RES1_MUX_POS_PIN0 = OPAMP_OPAMPCTRL_RES1MUX(0), OPAMP1_RES1_MUX_NEG_PIN0 = OPAMP_OPAMPCTRL_RES1MUX(1), OPAMP1_RES1_MUX_OUT0 = OPAMP_OPAMPCTRL_RES1MUX(2), OPAMP1_RES1_MUX_GND = OPAMP_OPAMPCTRL_RES1MUX(3) }
	Resistor 1 MUX selection configuration enum. More...

enum	opamp2_neg_mux { OPAMP2_NEG_MUX_PIN2 = OPAMP_OPAMPCTRL_MUXNEG(0), OPAMP2_NEG_MUX_TAP2 = OPAMP_OPAMPCTRL_MUXNEG(1), OPAMP2_NEG_MUX_OUT2 = OPAMP_OPAMPCTRL_MUXNEG(2), OPAMP2_NEG_MUX_PIN0 = OPAMP_OPAMPCTRL_MUXNEG(3), OPAMP2_NEG_MUX_PIN1 = OPAMP_OPAMPCTRL_MUXNEG(4), OPAMP2_NEG_MUX_DAC = OPAMP_OPAMPCTRL_MUXNEG(5) }
	Negative input MUX selection configuration enum. More...

enum	opamp2_pos_mux { OPAMP2_POS_MUX_PIN2 = OPAMP_OPAMPCTRL_MUXPOS(0), OPAMP2_POS_MUX_TAP2 = OPAMP_OPAMPCTRL_MUXPOS(1), OPAMP2_POS_MUX_OUT1 = OPAMP_OPAMPCTRL_MUXPOS(2), OPAMP2_POS_MUX_GND = OPAMP_OPAMPCTRL_MUXPOS(3), OPAMP2_POS_MUX_PIN0 = OPAMP_OPAMPCTRL_MUXPOS(4), OPAMP2_POS_MUX_PIN1 = OPAMP_OPAMPCTRL_MUXPOS(5), OPAMP2_POS_MUX_TAP0 = OPAMP_OPAMPCTRL_MUXPOS(6) }
	Positive input MUX selection configuration enum. More...

enum	opamp2_res1_mux { OPAMP2_RES1_MUX_POS_PIN0 = OPAMP_OPAMPCTRL_RES1MUX(0), OPAMP2_RES1_MUX_NEG_PIN0 = OPAMP_OPAMPCTRL_RES1MUX(1), OPAMP2_RES1_MUX_OUT1 = OPAMP_OPAMPCTRL_RES1MUX(2), OPAMP2_RES1_MUX_GND = OPAMP_OPAMPCTRL_RES1MUX(3) }
	Resistor 1 MUX selection configuration enum. More...

enum	opamp_bias_selection { OPAMP_BIAS_MODE_0 = OPAMP_OPAMPCTRL_BIAS(0), OPAMP_BIAS_MODE_1 = OPAMP_OPAMPCTRL_BIAS(1), OPAMP_BIAS_MODE_2 = OPAMP_OPAMPCTRL_BIAS(2), OPAMP_BIAS_MODE_3 = OPAMP_OPAMPCTRL_BIAS(3) }
	Bias mode selection MUX configuration enum. More...

enum	opamp_id { OPAMP_0 = 0, OPAMP_1 = 1, OPAMP_2 = 2, OPAMP_NUM }
	OPAMP ID number enum. More...

enum	opamp_pot_mux { OPAMP_POT_MUX_14R_2R = OPAMP_OPAMPCTRL_POTMUX(0), OPAMP_POT_MUX_12R_4R = OPAMP_OPAMPCTRL_POTMUX(1), OPAMP_POT_MUX_8R_8R = OPAMP_OPAMPCTRL_POTMUX(2), OPAMP_POT_MUX_6R_10R = OPAMP_OPAMPCTRL_POTMUX(3), OPAMP_POT_MUX_4R_12R = OPAMP_OPAMPCTRL_POTMUX(4), OPAMP_POT_MUX_3R_13R = OPAMP_OPAMPCTRL_POTMUX(5), OPAMP_POT_MUX_2R_14R = OPAMP_OPAMPCTRL_POTMUX(6), OPAMP_POT_MUX_R_15R = OPAMP_OPAMPCTRL_POTMUX(7) }
	Potentiometer selection MUX configuration enum. More...

Functions
void	opamp0_get_config_defaults (struct opamp0_config *const config)
	Initializes all members of OPAMP0 configuration structure to safe defaults. More...

void	opamp0_set_config (struct opamp0_config *const config)
	Writes OPAMP0 configuration to the hardware module. More...

void	opamp1_get_config_defaults (struct opamp1_config *const config)
	Initializes all members of OPAMP1 configuration structure to safe defaults. More...

void	opamp1_set_config (struct opamp1_config *const config)
	Writes OPAMP1 configuration to the hardware module. More...

void	opamp2_get_config_defaults (struct opamp2_config *const config)
	Initializes all members of OPAMP2 configuration structure to safe defaults. More...

void	opamp2_set_config (struct opamp2_config *const config)
	Writes OPAMP2 configuration to the hardware module. More...

void	opamp_disable (const enum opamp_id number)
	Disables an OPAMP that was previously enabled. More...

void	opamp_enable (const enum opamp_id number)
	Enables an OPAMP that was previously configured. More...

bool	opamp_is_ready (const enum opamp_id number)
	Checks an OPAMP output ready status. More...

static void	opamp_module_disable (void)
	Disables OPAMP module. More...

static void	opamp_module_enable (void)
	Enables OPAMP module. More...

void	opamp_module_init (void)
	Initializes OPAMP module. More...

static void	opamp_module_reset (void)
	Resets OPAMP module. More...

static void	opamp_voltage_doubler_disable (void)
	Disables OPAMP voltage doubler. More...

static void	opamp_voltage_doubler_enable (void)
	Enables OPAMP voltage doubler. More...

enum opamp0_neg_mux

Negative input MUX selection configuration enum.

Enum for the negative input of OPAMP0.

Enumerator
OPAMP0_NEG_MUX_PIN0	Negative I/O pin 0.
OPAMP0_NEG_MUX_TAP0	Resistor ladder 0 taps.
OPAMP0_NEG_MUX_OUT0	OPAMP output.
OPAMP0_NEG_MUX_DAC	DAC output.

enum opamp0_pos_mux

Positive input MUX selection configuration enum.

Enum for the positive input of OPAMP0.

Enumerator
OPAMP0_POS_MUX_PIN0	Positive I/O pin 0.
OPAMP0_POS_MUX_TAP0	Resistor ladder 0 taps.
OPAMP0_POS_MUX_DAC	DAC output.
OPAMP0_POS_MUX_GND	Ground.

enum opamp0_res1_mux

Resistor 1 MUX selection configuration enum.

Enum for the Resistor 1 of OPAMP0.

Enumerator
OPAMP0_RES1_MUX_POS_PIN0	Positive input of OPAMP0.
OPAMP0_RES1_MUX_NEG_PIN0	Negative input of OPAMP0.
OPAMP0_RES1_MUX_DAC	DAC output.
OPAMP0_RES1_MUX_GND	Ground.

enum opamp1_neg_mux

Negative input MUX selection configuration enum.

Enum for the negative input of OPAMP1.

Enumerator
OPAMP1_NEG_MUX_PIN1	Negative I/O pin 1.
OPAMP1_NEG_MUX_TAP1	Resistor ladder 1 taps.
OPAMP1_NEG_MUX_OUT1	OPAMP output.
OPAMP1_NEG_MUX_DAC	DAC output.

enum opamp1_pos_mux

Positive input MUX selection configuration enum.

Enum for the positive input of OPAMP1.

Enumerator
OPAMP1_POS_MUX_PIN1	Positive I/O pin 1.
OPAMP1_POS_MUX_TAP1	Resistor ladder 1 taps.
OPAMP1_POS_MUX_OUT0	OPAMP0 output.
OPAMP1_POS_MUX_GND	Ground.

enum opamp1_res1_mux

Resistor 1 MUX selection configuration enum.

Enum for the Resistor 1 of OPAMP1.

Enumerator
OPAMP1_RES1_MUX_POS_PIN0	Positive input of OPAMP1.
OPAMP1_RES1_MUX_NEG_PIN0	Negative input of OPAMP1.
OPAMP1_RES1_MUX_OUT0	OPAMP0 output.
OPAMP1_RES1_MUX_GND	Ground.

enum opamp2_neg_mux

Negative input MUX selection configuration enum.

Enum for the negative input of OPAMP2.

Enumerator
OPAMP2_NEG_MUX_PIN2	Negative I/O pin 2.
OPAMP2_NEG_MUX_TAP2	Resistor ladder 2 taps.
OPAMP2_NEG_MUX_OUT2	OPAMP output.
OPAMP2_NEG_MUX_PIN0	Negative I/O pin 0.
OPAMP2_NEG_MUX_PIN1	Negative I/O pin 1.
OPAMP2_NEG_MUX_DAC	DAC output.

enum opamp2_pos_mux

Positive input MUX selection configuration enum.

Enum for the positive input of OPAMP2.

Enumerator
OPAMP2_POS_MUX_PIN2	Positive I/O pin 2.
OPAMP2_POS_MUX_TAP2	Resistor ladder 2 taps.
OPAMP2_POS_MUX_OUT1	OPAMP1 output.
OPAMP2_POS_MUX_GND	Ground.
OPAMP2_POS_MUX_PIN0	Positive I/O pin 0.
OPAMP2_POS_MUX_PIN1	Positive I/O pin 1.
OPAMP2_POS_MUX_TAP0	Resistor ladder 0 taps.

enum opamp2_res1_mux

Resistor 1 MUX selection configuration enum.

Enum for the Resistor 1 of OPAMP2.

Enumerator
OPAMP2_RES1_MUX_POS_PIN0	Positive input of OPAMP2.
OPAMP2_RES1_MUX_NEG_PIN0	Negative input of OPAMP2.
OPAMP2_RES1_MUX_OUT1	OPAMP1 output.
OPAMP2_RES1_MUX_GND	Ground.

enum opamp_bias_selection

Bias mode selection MUX configuration enum.

Enum for the Bias mode selection of OPAMP 0 to 2.

Enumerator
OPAMP_BIAS_MODE_0	Minimum current consumption but the slowest mode.
OPAMP_BIAS_MODE_1	Low current consumption, slow speed.
OPAMP_BIAS_MODE_2	High current consumption, fast speed.
OPAMP_BIAS_MODE_3	Maximum current consumption but the fastest mode.

enum opamp_id

OPAMP ID number enum.

Enumerator
OPAMP_0	OPAMP 0.
OPAMP_1	OPAMP 1.
OPAMP_2	OPAMP 2.
OPAMP_NUM	OPAMP number.

enum opamp_pot_mux

Potentiometer selection MUX configuration enum.

Enum for the potentiometer selection of OPAMP 0 to 2.

Enumerator
OPAMP_POT_MUX_14R_2R	Gain = R2/R1 = 1/7.
OPAMP_POT_MUX_12R_4R	Gain = R2/R1 = 1/3.
OPAMP_POT_MUX_8R_8R	Gain = R2/R1 = 1.
OPAMP_POT_MUX_6R_10R	Gain = R2/R1 = 1 + 2/3.
OPAMP_POT_MUX_4R_12R	Gain = R2/R1 = 3.
OPAMP_POT_MUX_3R_13R	Gain = R2/R1 = 4 + 1/3.
OPAMP_POT_MUX_2R_14R	Gain = R2/R1 = 7.
OPAMP_POT_MUX_R_15R	Gain = R2/R1 = 15.

void opamp0_get_config_defaults ( struct opamp0_config *const config )

Initializes all members of OPAMP0 configuration structure to safe defaults.

Initializes all members of OPAMP0 configuration structure to safe defaults. This function should be called on all new instances of these configuration structures before being modified by the user application.

The default configuration is setting OPAMP0 as "Voltage Follower", refer to the first mode of "Built-in Modes" in the device datasheet.

Parameters

[out] config OPAMP0 configuration structure to initialize to default values

References _opamp_get_config_common_defaults(), Assert, opamp0_config::config_common, opamp0_config::negative_input, OPAMP0_NEG_MUX_OUT0, OPAMP0_POS_MUX_PIN0, OPAMP0_RES1_MUX_GND, opamp0_config::positive_input, and opamp0_config::r1_connection.

Referenced by configure_non_inverting_pga_opamp0().

void opamp0_set_config ( struct opamp0_config *const config )

Writes OPAMP0 configuration to the hardware module.

Writes a given OPAMP0 configuration to the hardware module.

Parameters

[in] config Pointer to the OPAMP0 configuration struct

References opamp_config_common::analog_out, opamp_config_common::bias_value, opamp0_config::config_common, opamp0_config::negative_input, opamp_config_common::on_demand, opamp0_config::positive_input, opamp_config_common::potentiometer_selection, opamp0_config::r1_connection, opamp_config_common::r1_enable, opamp_config_common::r2_out, opamp_config_common::r2_vcc, and opamp_config_common::run_in_standby.

Referenced by configure_non_inverting_pga_opamp0().

void opamp1_get_config_defaults ( struct opamp1_config *const config )

Initializes all members of OPAMP1 configuration structure to safe defaults.

Initializes all members of OPAMP1 configuration structure to safe defaults. This function should be called on all new instances of these configuration structures before being modified by the user application.

The default configuration is setting OPAMP1 as "Voltage Follower", refer to the first mode of "Built-in Modes" in the device datasheet.

Parameters

[out] config OPAMP1 configuration structure to initialize to default values

References _opamp_get_config_common_defaults(), Assert, opamp1_config::config_common, opamp1_config::negative_input, OPAMP1_NEG_MUX_OUT1, OPAMP1_POS_MUX_PIN1, OPAMP1_RES1_MUX_GND, opamp1_config::positive_input, and opamp1_config::r1_connection.

void opamp1_set_config ( struct opamp1_config *const config )

Writes OPAMP1 configuration to the hardware module.

Writes a given OPAMP1 configuration to the hardware module.

Parameters

[in] config Pointer to the OPAMP1 configuration struct

References opamp_config_common::analog_out, opamp_config_common::bias_value, opamp1_config::config_common, opamp1_config::negative_input, opamp_config_common::on_demand, opamp1_config::positive_input, opamp_config_common::potentiometer_selection, opamp1_config::r1_connection, opamp_config_common::r1_enable, opamp_config_common::r2_out, opamp_config_common::r2_vcc, and opamp_config_common::run_in_standby.

void opamp2_get_config_defaults ( struct opamp2_config *const config )

Initializes all members of OPAMP2 configuration structure to safe defaults.

Initializes all members of OPAMP2 configuration structure to safe defaults. This function should be called on all new instances of these configuration structures before being modified by the user application.

The default configuration is setting OPAMP2 as "Voltage Follower", refer to the first mode of "Built-in Modes" in the device datasheet.

Parameters

[out] config OPAMP2 configuration structure to initialize to default values

References _opamp_get_config_common_defaults(), Assert, opamp2_config::config_common, opamp2_config::negative_input, OPAMP2_NEG_MUX_OUT2, OPAMP2_POS_MUX_PIN2, OPAMP2_RES1_MUX_GND, opamp2_config::positive_input, and opamp2_config::r1_connection.

Referenced by configure_opamp2().

void opamp2_set_config ( struct opamp2_config *const config )

Writes OPAMP2 configuration to the hardware module.

Writes a given OPAMP2 configuration to the hardware module.

Parameters

[in] config Pointer to the OPAMP2 configuration struct

References opamp_config_common::analog_out, opamp_config_common::bias_value, opamp2_config::config_common, opamp2_config::negative_input, opamp_config_common::on_demand, opamp2_config::positive_input, opamp_config_common::potentiometer_selection, opamp2_config::r1_connection, opamp_config_common::r1_enable, opamp_config_common::r2_out, opamp_config_common::r2_vcc, and opamp_config_common::run_in_standby.

Referenced by configure_opamp2().

void opamp_disable ( const enum opamp_id number )

Disables an OPAMP that was previously enabled.

Disables an OPAMP that was previously enabled via a call to opamp_enable().

Parameters

[in] number OPAMP number to disable

References Assert, OPAMP_0, OPAMP_1, and OPAMP_2.

void opamp_enable ( const enum opamp_id number )

Enables an OPAMP that was previously configured.

Enables an OPAMP that was previously configured via a call to the set configuration function.

Parameters

[in] number OPAMP number to enable

References Assert, OPAMP_0, OPAMP_1, and OPAMP_2.

Referenced by configure_non_inverting_pga_opamp0(), and configure_opamp2().

bool opamp_is_ready ( const enum opamp_id number )

Checks an OPAMP output ready status.

Checks if an OPAMP output is ready.

Parameters

[in] number OPAMP number to check

Returns: Ready status of the select OPAMP.

Return values

false	If the select OPAMP output is not ready
ture	If the select OPAMP output is ready

References Assert, OPAMP_0, OPAMP_1, and OPAMP_2.

Referenced by configure_non_inverting_pga_opamp0(), and configure_opamp2().

static void opamp_module_disable ( void )

inlinestatic

Disables OPAMP module.

Disables the peripheral.

static void opamp_module_enable ( void )

inlinestatic

Enables OPAMP module.

Enable the peripheral. Each OPAMP must also be enabled individually by the Enable bit in the corresponding OPAMP Control register.

Referenced by opamp_module_init().

void opamp_module_init ( void )

Initializes OPAMP module.

Resets all registers in the MODULE to their initial state, and then enable the module.

References opamp_module_enable(), opamp_module_reset(), system_apb_clock_set_mask(), SYSTEM_CLOCK_APB_APBD, system_clock_source_osculp32k_get_config_defaults(), and system_clock_source_osculp32k_set_config().

Referenced by configure_non_inverting_pga_opamp0(), and configure_opamp2().

static void opamp_module_reset ( void )

inlinestatic

Resets OPAMP module.

Resets all registers in the MODULE to their initial state, and the OPAMP will be disabled.

Referenced by opamp_module_init().

static void opamp_voltage_doubler_disable ( void )

inlinestatic

Disables OPAMP voltage doubler.

The analog input MUXes have high resistance, but consume less power at lower voltages (e.g., the voltage doubler is disabled).

static void opamp_voltage_doubler_enable ( void )

inlinestatic

Enables OPAMP voltage doubler.

The analog input MUXes have low resistance, but consume more power at lower voltages (e.g., driven by the voltage doubler).

References system_clock_source_osculp32k_get_config_defaults(), and system_clock_source_osculp32k_set_config().

Microchip® Advanced Software Framework

Prerequisites

Module Overview

Special Considerations

Extra Information

Examples

API Overview

Modules

Data Structures

Enumerations

Functions