1FEATURES
2• Input Operating Voltage Range: 6V to 28V
• Absolute Maximum Input Rating: 30V
• Integrated 2A N-Channel Buck Switch
• Adjustable Current Limit Allows for Smaller
Inductor
• Adjustable Output Voltage from 2.51V
• Minimum Ripple Voltage at V OUT
• Power Good Output
• Switching Frequency Adjustable to 1MHz
• COT Topology Features:
– Switching Frequency Remains Nearly
Constant with Load Current and Input
Voltage Variations
– Ultra-Fast Transient Response
– No Loop Compensation Required
– Stable Operation with Ceramic Output
Capacitors lock–
Allows for Smaller Output Capacitor and
Current Sense Resistor
• Adjustable Soft-Start Timing
• Thermal Shutdown
• Precision 2% Feedback Reference

DESCRIPTION
The LM34922 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
voltage regulator contains an N-Channel 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 lockout,
and maximum duty cycle limit.