Datasheet Texas Instruments LM34914 — 数据表

LM34914
www.ti.com SNVS453B – MAY 2006 – REVISED MARCH 2013 LM34914 Ultra Small 1.25A Step-Down Switching Regulator with Intelligent Current Limit
Check for Samples: LM34914 FEATURES 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 ontime 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 WSON-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 undervoltage lock-out, thermal shutdown, gate drive undervoltage lock-out, and maximum duty cycle limit. 1 2 Input Voltage Range: 8V to 40V
Integrated N-Channel Buck Switch …