The LM25011 Constant On-time Step-Down Switching Regulator
features all the functions needed to implement a low
cost, efficient, buck bias regulator capable of supplying up to
2A of load current. This high voltage regulator contains an NChannel
Buck switch, a startup regulator, current limit detection,
and internal ripple control. The constant on-time
regulation principle requires no loop compensation, results in
fast load transient response, and simplifies circuit implementation.
The operating frequency remains constant with line
and load. The adjustable valley current limit detection results
in a smooth transition from constant voltage to constant current
mode when current limit is reached, without the use of
current limit foldback. The PGD output indicates the output
voltage has increased to within 5% of the expected regulation
value. Additional features include: Low output ripple, VIN under-
voltage lock-out, adjustable soft-start timing, thermal
shutdown, gate drive pre-charge, gate drive under-voltage
lock-out, and maximum duty cycle limit.