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 lock-out, and maximum duty cycle limit.

• 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 VOUT
• 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
  • Allows for Smaller Output Capacitor and Current Sense Resistor
• Adjustable Soft-Start Timing
• Thermal Shutdown
• Precision 2% Feedback Reference