In what situation would I use a constant-on-time (COT) buck? What are some advantages it has over a current mode device?
A COT architecture is a type of hysteretic mode that senses the output voltage directly from feedback resistors. The on time generator is activated when the feedback voltage reaches the reference voltage. Because of this simple control method and lack of extra components, the load transient performance is better compared to a current mode control.
The article below goes in-depth on the subject matter.