SPRSP85A April 2024 – September 2024 TMS320F28P550SJ , TMS320F28P559SJ-Q1
PRODMIX
The Comparator Subsystem (CMPSS) consists of analog comparators and supporting circuits that are useful for power applications such as peak current mode control, switched-mode power supply, power factor correction, voltage trip monitoring, and so forth.
The comparator subsystem is built around a number of modules. Each subsystem contains two comparators, two reference 12-bit DACs, and two digital filters. The subsystem also includes two ramp generators. The ramp generators ramp up and down. Comparators are denoted "H" or "L" within each module where “H” and “L” represent high and low, respectively. Each comparator generates a digital output which indicates whether the voltage on the positive input is greater than the voltage on the negative input. The positive input of the comparator is driven from an external pin (see the Analog Subsystem chapter of the TMS320F28P55x Real-Time Microcontrollers Technical Reference Manual for mux options available to the CMPSS). The negative input can be driven by an external pin or by the programmable reference 12-bit DAC. Each comparator output passes through a programmable digital filter that can remove spurious trip signals. An unfiltered output is also available if filtering is not required. Two ramp generator circuits are optionally available to control the reference 12-bit DAC values for the high and low comparators in the subsystem.The DAC along with a wrapper can be used to generate a ramp which is used for slope compensation in Peak Current Mode Control (PCMC) and other applications.
Each CMPSS includes: