FEATURES
• Integrated N-Channel buck switch
• Integrated start-up regulator
• Input Voltage Range: 8V to 40V
• No loop compensation required
• Ultra-Fast transient response
• Operating frequency remains constant with
load current and input voltage
• Maximum switching frequency: 2.0 MHz
• Maximum Duty Cycle Limited During Start-Up
• Adjustable output voltage
• Valley Current Limit At 0.64A
• Precision internal reference
• Low bias current
• Highly efficient operation
• Thermal shutdown
• 10-Pin DSBGA Package

APPLICATIONS
• High Efficiency Point-Of-Load (POL) Regulator
• Non-Isolated Telecommunication Buck
Regulator
• Secondary High Voltage Post Regulator

DESCRIPTION
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 10-pin DSBGA 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.