LM34919

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
VIN to RTN 44V
BST to RTN 52V
SW to RTN (Steady State) -1.5V
ESD Rating (Note 2)
Human Body Model 2kV
BST to VCC 44V
VIN to SW 44V
BST to SW 14V
VCC to RTN 14V
SGND to RTN -0.3V to +0.3V
SS to RTN -0.3V to 4V
All Other Inputs to RTN -0.3 to 7V
Storage Temperature Range -65 to +150
JunctionTemperature 150

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 of LM34919 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.