LM34914 Ultra Small 1.25A Step-Down Switching Regulator with Intelligent Current Limit

Part Number(s) (NSID)	Top View	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM34914SD/NOPB LM34914SD		LLP	10	1 1	260 260	Detail	N/A	N/A	ZXYTT 34914
LM34914SDX/NOPB LM34914SDX		LLP	10	1 1	260 260	Detail	N/A	N/A	ZXYTT 34914

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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

Diagrams

Typical Application *click for larger image	Block Diagram *click for larger image
Typical Performance *click for larger image