3.2.6 Comparator with DAC (CMP DAC)
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 analog comparator module can be used to implement Peak Current mode control, Critical Conduction mode (variable frequency) and Hysteretic Control mode.
Using The Library
The High-Speed Analog Comparator with Slope Compensation DAC consists of the following key features:
• Programmable Comparator Hysteresis
• Programmable Output Polarity
• Interrupt Generation Capability
• Dedicated 12-bit Resolution Pulse Density Modulation (PDM) Digital-to-Analog Converter (DAC) for each Analog Comparator
• Multimode Multipole RC Output Filter:
– Transition mode: provides the fastest response
– Fast mode: for tracking DAC slopes
– Steady-State mode: provides 12-bit resolution
• Dedicated Support for the Following Modes:
– Slope Generation
– Hysteretic Control
– Triangular Wave
Library Interface
This peripheral library provides the following interfaces:
Functions
| Name | Description |
|---|---|
| CMPx_Initialize | Initializes CMPx module of the device |
| CMPx_Deinitialize | Deinitializes the CMPx module of the device to POR values |
| CMPx_Calibrate | Calibrates the CMPx module and enables ripple reduction mode |
| CMPx_StatusGet | Returns the output status of a comparator |
| CMPx_Enable | Enables the common DAC module |
| CMPx_Disable | Disables the common DAC module |
| CMPx_DACEnable | Enables the individual DAC module |
| CMPx_DACDisable | Disables the individual DAC module |
| CMPx_DACDataWrite | Writes DAC data to register |
| CMPx_DACDataHighWrite | Sets higher limit of the slope |
| CMPx_DACDataLowWrite | Sets lower limit of the slope |
| CMPx_DACSlopeWrite | Sets slope rate |
| CMPx_DACSlopeUpdateMode | Updates slope modes specified in CMP_DAC_SLOPE_UPDATE_MODE |
Data types and constants
| Name | Type | Description |
|---|---|---|
| CMP_DAC_SLOPE_UPDATE_MODE | Enum | CMP slope data registers update mode |
| CMP_CALLBACK | Typedef | Defines the function pointer data type and function signature for the CMP callback function |