Following are the details-
1) Comparator goes to unity feedback and then openloop - 222.22k
2) There are some caps and they either get connected b/w input of comparator and Supply or Input of comparator and ground- 2MHz
3) There is one switched cap BGREF. When comparator goes in unity feedback, there is charge in the capacitors due to bandgap. When compartor goes into openloop , input gets connected and input charge is compared to bandgap charge. Depending on the difference, the comparator switches. No such defined frequency but should finish operation in the open loop mode of comparator.