LM34914 Ultra Small 1.25A Step-Down Switching Regulator with Intelligent Current Limit
December 20, 2007
LM34914 Ultra...
LM34914 Ultra Small 1.25A Step-Down Switching
Regulator with Intelligent Current Limit
December 20, 2007
LM34914 Ultra Small 1.25A Step-Down Switching
Regulator with Intelligent Current Limit
General Description
The LM34914 Step-Down Switching
Regulator features all the functions needed to implement a low cost, efficient, buck bias
regulator capable of supplying at least 1.25A to the load. To reduce excessive switch current due to the possibility of a saturating inductor the valley current limit threshold changes with input and output voltages, and the on-time is reduced when current limit is detected. This buck
regulator contains a 44V N-Channel Buck Switch, and is available in the thermally enhanced 3 mm x 3 mm LLP-10 package. The 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 lock-out, thermal shutdown, gate drive under-voltage lock-out, and maximum duty cycle limit.
Features
■ Input Voltage Range: 8V to 40V ■ Integrated N-Channel buck switch
■ Valley current limit varies with VIN and VO...