VIN

SW

BST

LM34919B

VCC

SS

RON/SD

6V - 40V

Input

C1

RON

R2

R1

C2

VOUT

L1

C3

C4

D1

C6

RTN

ISEN

SGND

FB

SHUTDOWN

R3

LM34919B

LM34919B-Q1

www.ti.com

SNVS623B – MAY 2010 – REVISED JULY 2013

LM34919B Ultra-Small 40-V 600-mA Constant On-Time

Buck Switching Regulator

Check for Samples: LM34919B, LM34919B-Q1

1

FEATURES

TYPICAL APPLICATIONS

2

•

AEC-Q100 Grade 1 Qualified (-40°C to 125°C)

•

Automotive Safety and Infotainment

•

Maximum Switching Frequency: 2.6 MHz

•

High Efficiency Point-Of-Load (POL) Regulator

(VIN=14V,Vo=3.3V)

•

Non-Isolated Telecommunication Buck

•

Input Voltage Range: 6V to 40V

Regulator

•

Integrated N-Channel Buck Switch

•

Secondary High Voltage Post Regulator

•

Integrated Startup Regulator

DESCRIPTION

•

No loop compensation Required

The

LM34919B

Step-Down

Switching

Regulator

•

Ultra-Fast transient Response

features all of the functions needed to implement a

•

Operating frequency remains constant with

low cost, efficient, buck bias regulator capable of

Load Current and Input Voltage

supplying 0.6A to the load. This buck regulator

contains an N-Channel Buck Switch, and is available

•

Maximum Duty Cycle Limited During Startup

in a 10-pin DSBGA package. The constant on-time

•

Adjustable Output Voltage

feedback

regulation

scheme

requires

no

loop

•

Valley Current Limit At 0.64A

compensation, results in fast load transient response,

and simplifies circuit implementation. The operating

•

Precision Internal Reference

frequency remains constant with line and load

•

Low Bias Current

variations due to the inverse relationship between the

•

Highly Efficient Operation

input voltage and the on-time. The valley current limit

results in a smooth transition from constant voltage to

•

Thermal Shutdown

constant current mode when current limit is detected,

•

10-Pin DSBGA Package

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.

Basic Step-Down Regulator

1

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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

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PRODUCTION DATA information is current as of publication date.

Copyright © 2010–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.