The LM34919 Step Down Switching Regulator features all of
the functions needed to implement a low cost, efficient, buck
bias regulator capable of supplying 0.6A to the load. This buck
regulator contains an N-Channel Buck Switch, and is available
in a micro SMD package. The constant on-time feedback
regulation scheme requires no loop compensation, results in
fast load transient response, and simplifies circuit implementation.
The operating frequency remains constant with line
and load variations due to the inverse relationship between
the input voltage and the on-time. The valley current limit results
in a smooth transition from constant voltage to constant
current mode when current limit is detected, reducing the frequency
and output voltage, without the use of foldback. Additional
features include: VCC under-voltage lockout, thermal
shutdown, gate drive under-voltage lockout, and maximum
duty cycle limiter.