2.4 CMP DAC Driver

Overview

The high-speed analog comparator module provides a method to monitor voltage, current and other critical signals in a power conversion application that may be too fast for the CPU and ADC to capture.

The high-speed analog comparator module is comprised of a high-speed comparator, Pulse Density Modulation (PDM) DAC and a slope compensation unit. The slope compensation unit provides a user-defined slope which can be used to alter the DAC output. This feature is useful in applications, such as Peak Current mode control, where slope compensation is required to maintain the stability of the power supply

Features

The user can configure the DAC Mode based on their application needs.
There are four modes supported : DC-Mode, Slope Mode, Hysteretic Mode and Triangle Wave Mode.
The Clock and Divider settings can be configured in the PLIB dependency of the driver module.

DAC Modes

DC-Mode

The DC mode is the default mode of operation of the DAC. The other modes use slope generator to vary the DAC data value at a user-defined rate to reach a desired endpoint value.

Slope Mode

The slope generator function can be utilized in Peak Current mode control-based power supply applications, where slope compensation is required. The slope function modifies the non-slope PDM DAC value repeatedly, at a user-defined rate, until the DAC data value reaches its endpoint.

Hysteretic Mode

Hysteretic mode control is sometimes called “Bang-Bang” control, where a signal within a power converter is controlled within an upper cutoff and a lower cutoff limit. The Hysteretic mode is used in power supply applications utilizing hysteretic control, such as LED drivers.

Triangle Wave Mode

Triangle Wave mode generates an output voltage that rises and falls with a triangle wave pattern.

2.4.1 Module Documentation

2.4.1.1 CMP DAC Driver

High Speed Analog Comparator with Slope Compensation DAC driver using dsPIC MCUs.

2.4.1.1.1 Module description

High Speed Analog Comparator with Slope Compensation DAC driver using dsPIC MCUs.

Data structures

struct DAC_DC_INTERFACE

Structure containing the function pointers of DAC driver in DC mode.
struct CMP_INTERFACE

Structure containing the function pointers of CMP driver.

Functions

void CMP1_Initialize (void)

Initialize the CMP1 module.
void CMP1_Deinitialize (void)

Deinitializes the CMP1 to POR values.
bool CMP1_StatusGet (void)

Returns the comparator output status.
void CMP1_Enable (void)

Enables the common DAC module.
void CMP1_Disable (void)

Disables the common DAC module.
void CMP1_DACEnable (void)

Enables the individual DAC module.
void CMP1_DACDisable (void)

Disables the individual DAC module.
void CMP1_DACDataWrite (size_t value)

CMP DAC Data write to register.
void CMP1_EventCallbackRegister (void(*handler)(void))

This function can be used to override default callback and to define custom callback for CMP1 Event event.
void CMP1_EventCallback (void)

This is the default callback with weak attribute.
void CMP1_Tasks (void)

The Task function can be called in the main application using the High Speed.

Variables

const struct CMP_INTERFACE CMP_DAC1

Structure object of type CMP_INTERFACE with the custom name given by the user in the Melody Driver User interface.

2.4.1.1.2 Function Documentation

CMP1_DACDataWrite()

void CMP1_DACDataWrite (size_t value)

CMP DAC Data write to register.

Parameters:
in	value	- DAC Data write value

Returns:
none

CMP1_DACDisable()

void CMP1_DACDisable (void )

Disables the individual DAC module.

Parameters:
none

Returns:
none

CMP1_DACEnable()

void CMP1_DACEnable (void )

Enables the individual DAC module.

Parameters:
none

Returns:
none

CMP1_Deinitialize()

void CMP1_Deinitialize (void )

Deinitializes the CMP1 to POR values.

Parameters:
none

Returns:
none

CMP1_Disable()

void CMP1_Disable (void )

Disables the common DAC module.

Parameters:
none

Returns:
none

CMP1_Enable()

void CMP1_Enable (void )

Enables the common DAC module.

Parameters:
none

Returns:
none

CMP1_EventCallback()

void CMP1_EventCallback (void )

This is the default callback with weak attribute.

The user can override and implement the default callback without weak attribute or can register a custom callback function using

CMP1_EventCallbackRegister.

Parameters:
none

Returns:
none

CMP1_EventCallbackRegister()

void CMP1_EventCallbackRegister (void(*)(void) handler)

This function can be used to override default callback and to define custom callback for CMP1 Event event.

Parameters:
in	handler	- Address of the callback function.

Returns:
none

CMP1_Initialize()

void CMP1_Initialize (void )

Initialize the CMP1 module.

Parameters:
none

Returns:
none

CMP1_StatusGet()

bool CMP1_StatusGet (void )

Returns the comparator output status.

Parameters:
none

Returns:
true - Comparator output is high false - Comparator output is low

CMP1_Tasks()

void CMP1_Tasks (void )

The Task function can be called in the main application using the High Speed.

Comparator, when interrupts are not used. This would thus introduce the polling mode feature of the Analog Comparator.

Parameters:
none

Returns:
none

2.4.1.1.3 Variable Documentation

CMP_DAC1

const struct CMP_INTERFACE CMP_DAC1

Structure object of type CMP_INTERFACE with the custom name given by the user in the Melody Driver User interface.

The default name e.g. CMP_DAC1 can be changed by the user in the CMP user interface. This allows defining a structure with application specific name using the 'Custom Name' field. Application specific name allows the API Portability.

2.4.2 Class Documentation

2.4.2.1 CMP_INTERFACE Struct Reference

Structure containing the function pointers of CMP driver.

2.4.2.1.1 Detailed Description

Structure containing the function pointers of CMP driver.

#include <cmp_interface.h>

Public Attributes

void(* Initialize )(void)

Pointer to CMPx_Initialize e.g. CMP1_Initialize.
void(* Deinitialize )(void)

Pointer to CMPx_Deinitialize e.g. CMP1_Deinitialize.
void(* Enable )(void)

Pointer to CMPx_Enable e.g. CMP1_Enable.
void(* Disable )(void)

Pointer to CMPx_Disable e.g. CMP1_Disable.
bool(* StatusGet )(void)

Pointer to CMPx_StatusGet e.g. CMP1_StatusGet.
void(* EventCallbackRegister )(void(*handler)(void))

Pointer to CMPx_EventCallbackRegister e.g. CMP1_EventCallbackRegister.
void(* Tasks )(void)

Pointer to CMPx_Tasks e.g. CMP1_Tasks (Supported only in polling mode)
const struct DAC_DC_INTERFACE * cmp_dac_dc_interface

Pointer to DAC_DC_INTERFACE.

2.4.2.1.2 Member Data Documentation

The documentation for this struct was generated from the following file:

source/

cmp_interface.h

cmp_dac_dc_interface

const struct DAC_DC_INTERFACE* cmp_dac_dc_interface

Pointer to DAC_DC_INTERFACE.

Deinitialize

void(* Deinitialize) (void)

Pointer to CMPx_Deinitialize e.g. CMP1_Deinitialize.

Disable

void(* Disable) (void)

Pointer to CMPx_Disable e.g. CMP1_Disable.

Enable

void(* Enable) (void)

Pointer to CMPx_Enable e.g. CMP1_Enable.

EventCallbackRegister

void(* EventCallbackRegister) (void(*handler)(void))

Pointer to CMPx_EventCallbackRegister e.g. CMP1_EventCallbackRegister.

Initialize

void(* Initialize) (void)

Pointer to CMPx_Initialize e.g. CMP1_Initialize.

StatusGet

bool(* StatusGet) (void)

Pointer to CMPx_StatusGet e.g. CMP1_StatusGet.

Tasks

void(* Tasks) (void)

Pointer to CMPx_Tasks e.g. CMP1_Tasks (Supported only in polling mode)

2.4.2.2 DAC_DC_INTERFACE Struct Reference

Structure containing the function pointers of DAC driver in DC mode.

2.4.2.2.1 Detailed Description

Structure containing the function pointers of DAC driver in DC mode.

#include <cmp_interface.h>

Public Attributes

void(* Enable )(void)

Pointer to CMPx_DACEnable e.g. CMP1_DACEnable.
void(* Disable )(void)

Pointer to CMPx_DACDisable e.g. CMP1_DACDisable.
void(* DataWrite )(size_t value)

Pointer to CMPx_DACDataWrite e.g. CMP1_DACDataWrite.

2.4.2.2.2 Member Data Documentation

The documentation for this struct was generated from the following file:

source/

cmp_interface.h

DataWrite

void(* DataWrite) (size_t value)

Pointer to CMPx_DACDataWrite e.g. CMP1_DACDataWrite.

Disable

void(* Disable) (void)

Pointer to CMPx_DACDisable e.g. CMP1_DACDisable.

Enable

void(* Enable) (void)

Pointer to CMPx_DACEnable e.g. CMP1_DACEnable.

2.4.3 File Documentation

2.4.3.1 source/cmp1.h File Reference

This is the generated driver header file for the CMP1 driver.

#include <stddef.h>
#include <stdbool.h>
#include "cmp_interface.h"

2.4.3.1.1 Functions

void CMP1_Initialize (void)

Initialize the CMP1 module.
void CMP1_Deinitialize (void)

Deinitializes the CMP1 to POR values.
bool CMP1_StatusGet (void)

Returns the comparator output status.
void CMP1_Enable (void)

Enables the common DAC module.
void CMP1_Disable (void)

Disables the common DAC module.
void CMP1_DACEnable (void)

Enables the individual DAC module.
void CMP1_DACDisable (void)

Disables the individual DAC module.
void CMP1_DACDataWrite (size_t value)

CMP DAC Data write to register.
void CMP1_EventCallbackRegister (void(*handler)(void))

This function can be used to override default callback and to define custom callback for CMP1 Event event.
void CMP1_EventCallback (void)

This is the default callback with weak attribute.
void CMP1_Tasks (void)

The Task function can be called in the main application using the High Speed.

2.4.3.1.2 Variables

const struct CMP_INTERFACE CMP_DAC1

Structure object of type CMP_INTERFACE with the custom name given by the user in the Melody Driver User interface.

2.4.3.1.3 Detailed Description

This is the generated driver header file for the CMP1 driver.

CMP1 Generated Driver Header File

2.4.3.2 source/cmp_interface.h File Reference

#include <stdbool.h>
#include <stddef.h>

2.4.3.2.1 Data structures

struct DAC_DC_INTERFACE

Structure containing the function pointers of DAC driver in DC mode.
struct CMP_INTERFACE

Structure containing the function pointers of CMP driver.

2.4.3.2.2 Detailed Description

CMP Generated Driver Interface Header File