Analog Comparator#
Introduction#
An analog comparator in a micro-controller is a peripheral that compares two analog input voltages and generates a digital output based on the comparison result. It typically has two input pins for comparing analog voltages and an output pin for displaying the result of the comparison.
Analog comparators typically work in one of two modes:
Voltage Comparison Mode: In this mode, the comparator compares the voltages across its two input pins. If the voltage at the non-inverting input (+) exceeds the voltage at the inverting input (-), the output becomes high and interrupt occurs. The output becomes low if the voltage at the inverting input (-) is higher.
If the voltage at the inverting input (-) is higher, the output becomes low.
External and Internal Voltage comparison: This mode lets you compare the external input voltage to internal voltage generated using resister bank or reference scaler.
The comparator's output can be used to initiate interrupts, wake up the micro-controller from low-power mode, or control other system components using analog voltage levels.
Analog comparators are commonly employed in applications such as battery monitoring, threshold detection, sensor interface, and many more where analog signals must be compared and acted on digitally by the micro-controller.
It can compare DAC and OPAMP outputs with external or Internal voltages.
Configuration#
It sets the reference LDO voltage, set the non-inverting and inverting inputs, configures the pins in case of external inputs. Set the value of the scaler factor, if the input is a ref scaler. Set the threshold value, if the input consists of a bank of resistors. Once everything is configured, we will activate interrupts and registers callback.
To configure the non-inverting-input or inverting -input, hysteresis value and set filter enable or disable use the structure sl_analog_comparator_config_t to update the required configuration and call the API sl_si91x_analog_comparator_set_configurations().
For more information on configuring available parameters refer to the respective peripheral example readme document.
Usage#
The common Analog Comparator functions can be used after the Analog Comparator Structures are specified, passing an instance of sl_analog_comparator_config_t These functions will initiate and configure the Analog Comparator below, which is the flow for implementation.
sl_si91x_analog_comparator_set_reference_scaler_output (If input is Reference scaler)
sl_si91x_analog_comparator_set_resistor_bank_threshold ( If input is Resistor bank)
Modules#
Enumerations#
Enumeration to represent the analog comparator number.
Enumeration to represent analog comparator inputs.
Enumeration to represent the hysteresis control values.
Enumeration to represent BOD threshold values for resistor bank output.
Enumeration to represent scale factor values for reference scaler output.
Typedefs#
Typedef for the function pointer of the callback function.
Functions#
Initialize Analog Comparator.
Configure Analog Comparator.
Register Analog Comparator interrupt callback.
Unregister Analog Comparator interrupt callback.
Configure Analog Comparator resistor bank threshold.
Configure Analog Comparator reference scaler.
De-Initialize Analog Comparator.
Enumeration Documentation#
sl_analog_comparator_number_t#
sl_analog_comparator_number_t
Enumeration to represent the analog comparator number.
Enumerator | |
---|---|
SL_COMPARATOR_1 | Analog comparator 1. |
SL_COMPARATOR_2 | Analog comparator 2. |
SL_COMPARATOR_LAST | Last member of enum for validation. |
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sl_analog_comparator_inputs_t#
sl_analog_comparator_inputs_t
Enumeration to represent analog comparator inputs.
Enumerator | |
---|---|
SL_COMPARATOR_GPIO_INPUT_0 | Select GPIO input for comparator non-inverting input. |
SL_COMPARATOR_GPIO_INPUT_1 | Select GPIO input for comparator non-inverting input. |
SL_COMPARATOR_DAC_OUTPUT | Selects DAC output as comparator input. |
SL_COMPARATOR_REFERENCE_BUFFER_OUTPUT | Selects reference buffer output as comparator input. |
SL_COMPARATOR_REFERENCE_SCALER_OUTPUT | Selects reference scaler output as comparator input. |
SL_COMPARATOR_RESISTOR_BANK_OUTPUT | Selects resistor bank output as comparator input. |
SL_COMPARATOR_OPAMP1_OUTPUT | Selects OPAMP1 output as comparator input. |
SL_COMPARATOR_OPAMP2_OUTPUT | Selects OPAMP2 output as comparator input. |
SL_COMPARATOR_OPAMP3_OUTPUT | Selects OPAMP3 output as comparator input. |
SL_COMPARATOR_INPUT_LAST | Last member of enum for validation. |
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sl_analog_comparator_hystersis_values_t#
sl_analog_comparator_hystersis_values_t
Enumeration to represent the hysteresis control values.
Enumerator | |
---|---|
SL_COMPARATOR_HYSTERSIS_VALUE_0 | For hysteresis control value 0. |
SL_COMPARATOR_HYSTERSIS_VALUE_1 | For hysteresis control value 1. |
SL_COMPARATOR_HYSTERSIS_VALUE_2 | For hysteresis control value 2. |
SL_COMPARATOR_HYSTERSIS_VALUE_3 | For hysteresis control value 3. |
SL_COMPARATOR_HYSTERSIS_VALUE_LAST | Last member of enum for validation. |
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
sl_analog_comparator_threshold_values_t#
sl_analog_comparator_threshold_values_t
Enumeration to represent BOD threshold values for resistor bank output.
Enumerator | |
---|---|
SL_COMPARATOR_THRESHOLD_VALUE_FOR_2_33_VOLT | threshold value to get 2.33V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_2_27_VOLT | threshold value to get 2.27V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_2_21_VOLT | threshold value to get 2.21V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_2_15_VOLT | threshold value to get 2.15V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_2_10_VOLT | threshold value to get 2.10V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_2_05_VOLT | threshold value to get 2.05V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_2_00_VOLT | threshold value to get 2.0V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_95_VOLT | threshold value to get 1.95V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_91_VOLT | threshold value to get 1.91V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_86_VOLT | threshold value to get 1.86V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_82_VOLT | threshold value to get 1.82V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_79_VOLT | threshold value to get 1.79V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_75_VOLT | threshold value to get 1.75V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_71_VOLT | threshold value to get 1.71V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_68_VOLT | threshold value to get 1.68V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_64_VOLT | threshold value to get 1.64V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_61_VOLT | threshold value to get 1.61V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_58_VOLT | threshold value to get 1.58V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_55_VOLT | threshold value to get 1.55V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_53_VOLT | threshold value to get 1.53V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_50_VOLT | threshold value to get 1.50V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_47_VOLT | threshold value to get 1.47V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_45_VOLT | threshold value to get 1.45V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_42_VOLT | threshold value to get 1.42V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_40_VOLT | threshold value to get 1.40V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_38_VOLT | threshold value to get 1.38V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_35_VOLT | threshold value to get 1.35V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_33_VOLT | threshold value to get 1.33V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_31_VOLT | threshold value to get 1.31V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_29_VOLT | threshold value to get 1.29V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_27_VOLT | threshold value to get 1.27V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_FOR_1_25_VOLT | threshold value to get 1.25V as resistor bank output voltage |
SL_COMPARATOR_THRESHOLD_VALUE_LAST | Last member of enum for validation. |
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
sl_analog_comparator_scale_factor_values_t#
sl_analog_comparator_scale_factor_values_t
Enumeration to represent scale factor values for reference scaler output.
Enumerator | |
---|---|
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_0_1_VOLT | scale factor value to get 0.1V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_0_2_VOLT | scale factor value to get 0.2V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_0_3_VOLT | scale factor value to get 0.3V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_0_4_VOLT | scale factor value to get 0.4V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_0_5_VOLT | scale factor value to get 0.5V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_0_6_VOLT | scale factor value to get 0.6V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_0_7_VOLT | scale factor value to get 0.7V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_0_8_VOLT | scale factor value to get 0.8V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_0_9_VOLT | scale factor value to get 0.9V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_1_VOLT | scale factor value to get 1V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_FOR_1_1_VOLT | scale factor value to get 1.1V as reference scaler output voltage |
SL_COMPARATOR_SCALE_FACTOR_VALUE_LAST | Last member of enum for validation. |
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
Typedef Documentation#
sl_analog_comparator_callback_t#
typedef void(* sl_analog_comparator_callback_t) (void) )(void)
Typedef for the function pointer of the callback function.
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
Function Documentation#
sl_si91x_analog_comparator_init#
void sl_si91x_analog_comparator_init (void )
Initialize Analog Comparator.
N/A |
Enables system core clock and Auxiliary clock with 32MHZ RC clock. Configures reference LDO voltage as 2.8v
Returns
None
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
sl_si91x_analog_comparator_set_configurations#
sl_status_t sl_si91x_analog_comparator_set_configurations (sl_analog_comparator_config_t * comparator_config_ptr)
Configure Analog Comparator.
[in] | comparator_config_ptr | Pointer to analog comparator configuration structure sl_analog_comparator_config_t |
Use this function to configure analog comparator number, select non-inverting and inverting inputs, enable or disable hysteresis, and enable or disable filter for comparator outputs. Also configure input pins.
Pre-condition:
Returns
Status 0 if successful, else error code:
SL_STATUS_INVALID_PARAMETER (0x0021) - Analog comparator configuration structure member has invalid value.
SL_STATUS_OK (0x0000) - Success, analog comparator parameters configured properly.
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
sl_si91x_analog_comparator_register_callback#
sl_status_t sl_si91x_analog_comparator_register_callback (sl_analog_comparator_number_t comparator_number, sl_analog_comparator_callback_t on_comparator_callback)
Register Analog Comparator interrupt callback.
[in] | comparator_number | For comparator Number, see sl_analog_comparator_number_t for possible values. |
[in] | on_comparator_callback | Callback function pointer, to be invoked when a comparator interrupt occurs. |
Enables its interrupts as per comparator number
Pre-conditions:
sl_si91x_analog_comparator_unregister_callback(), if already registered for any interrupt
Returns
Status 0 if successful, else error code:
SL_STATUS_NULL_POINTER (0x0022) - on_comparator_callback parameter is a null pointer.
SL_STATUS_BUSY (0x0004) - The callback is already registered, unregister previous callback before registering new one.
SL_STATUS_INVALID_PARAMETER (0x0021) - comparator_number parameter has invalid value.
SL_STATUS_OK (0x0000) - Successfully registered timer timer-out callback.
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
sl_si91x_analog_comparator_unregister_callback#
sl_status_t sl_si91x_analog_comparator_unregister_callback (sl_analog_comparator_number_t comp_number)
Unregister Analog Comparator interrupt callback.
[in] | comp_number | For comparator Number, see sl_analog_comparator_number_t for possible values. |
Disables its interrupts as per comparator number
Pre-conditions:
Returns
Status 0 if successful, else error code:
SL_STATUS_INVALID_PARAMETER (0x0021) - comparator_number parameter has invalid value.
SL_STATUS_OK (0x0000) - Successfully registered timer timer-out callback.
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
sl_si91x_analog_comparator_set_resistor_bank_threshold#
sl_status_t sl_si91x_analog_comparator_set_resistor_bank_threshold (sl_analog_comparator_threshold_values_t threshold_value)
Configure Analog Comparator resistor bank threshold.
[in] | threshold_value | For comparator resistor bank, see sl_analog_comparator_threshold_values_t for possible values. |
As per the threshold value, resistor bank output voltage will be configured. Use this API when any GPIO or external input needs to compare with internal input (resistor bank).
Pre-conditions:
Returns
Status 0 if successful, else error code:
SL_STATUS_INVALID_PARAMETER (0x0021) - threshold_value parameter has invalid value.
SL_STATUS_OK (0x0000) - Successfully registered timer timer-out callback.
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
sl_si91x_analog_comparator_set_reference_scaler_output#
sl_status_t sl_si91x_analog_comparator_set_reference_scaler_output (sl_analog_comparator_scale_factor_values_t scale_factor_value)
Configure Analog Comparator reference scaler.
[in] | scale_factor_value | For comparator's reference scale, see sl_analog_comparator_scale_factor_values_t for possible values. |
Sets the scale factor for the analog comparator module's reference scaler. As per this scale factor, reference scalar output voltage will be set. Use this API when any GPIO or external input needs to compare with internal input (reference scaler).
Pre-conditions:
Returns
Status 0 if successful, else error code:
SL_STATUS_INVALID_PARAMETER (0x0021) - scale_factor_value parameter has invalid value.
SL_STATUS_OK (0x0000) - Successfully registered timer timer-out callback.
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h
sl_si91x_analog_comparator_deinit#
void sl_si91x_analog_comparator_deinit (void )
De-Initialize Analog Comparator.
N/A |
Disables Peripheral clock and interrupts Returns
None
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of file components/device/silabs/si91x/mcu/drivers/unified_api/inc/sl_si91x_analog_comparator.h