All the DAC channels can be configured as programmable comparators in the voltage-output mode. To enter the comparator mode for a channel, write 1 to the CMP-X-EN bit in the respective DAC-X-VOUT-CMP-CONFIG register. The comparator output can be configured as push-pull or open-drain using the CMP-X-OD-EN bit. To enable the comparator output on the output pin, write 1 to the CMP-X-OUT-EN bit. To invert the comparator output, write 1 to the CMP-X-INV-EN bit. The FBx pin has a finite impedance. By default, the FBx pin is in the high-impedance mode. To disable high-impedance on the FBx pin, write 1 to the CMP-X-HIZ-IN-DIS bit. Table 7-1 shows the comparator output at the pin for different bit settings.
|0||X||X||X||Comparator not enabled|
|1||1||0||1||Push-pull and inverted output|
|1||1||1||1||Open-drain and inverted output|
Figure 7-3 shows the interface circuit when all the DAC channels are configured as comparators. The programmable comparator operation is as shown in Figure 7-4. Individual comparator channels can be configured in no-hysteresis, with-hysteresis, and window-comparator modes using the CMP-X-MODE bit in the respective DAC-X-CMP-MODE-CONFIG register, as shown in Table 7-2.
|CMP-X-MODE BIT FIELD||COMPARATOR CONFIGURATION|
|00||Normal comparator mode. No hysteresis or window operation.|
|01||Hysteresis comparator mode. DAC-X-MARGIN-HIGH and DAC-X-MARGIN-LOW registers set the hysteresis.|
|10||Window comparator mode. DAC-X-MARGIN-HIGH and DAC-X-MARGIN-LOW registers set the window bounds.|