FB

SNS

FPWM

PGND

CSL

LG

ILIM

SW/CSH

HG

BOOST

Q1

Q2

D1

LM3495

SGND

FREQ/SYNC

COMP/SD

VIN

VLIN5

TRACK

VLIN5

L1

LM3495

www.ti.com

SNVS410E – FEBRUARY 2006 – REVISED NOVEMBER 2007

LM3495 Emulated Peak Current Mode Buck Controller for Low Output Voltage

Check for Samples: LM3495

1

FEATURES

•

On-chip gate drivers

•

Soft output discharge during shutdown

2

•

Input voltage from 2.9V to 18V

•

Startup into output pre-bias

•

Output voltage adjustable from 0.6V to 5.5V

•

Operation from a single input rail

•

Feedback Accuracy: ±1%

•

Adaptive Duty Cycle Limit

•

Low-side Sensing, Programmable Current

Limit without sense resistor

•

TSSOP-16 package

•

Input Under Voltage Lockout

APPLICATIONS

•

Hiccup mode current limit protection

eliminates thermal runaway during fault

•

Wide input voltage buck converters with low

conditions

voltage, high accuracy outputs

•

Internal soft start with tracking capability

•

Core logic regulators

•

200 kHz to 1.5 MHz Switching frequency,

•

High-efficiency buck regulation

Synchronizable

DESCRIPTION

The LM3495 is a PWM buck regulator which implements a unique emulated peak current mode control. This

control method eliminates the switching noise which typically limits current mode operation at extremely short

duty cycles and high operating frequency. The switching frequency is programmable between 200 kHz and 1.5

MHz, and can also be synchronized to an external clock. The LM3495 is also very fault tolerant with both switch

node short, hiccup mode, and adaptive duty cycle limit protection. A 0.6V 1% reference and glitch free pre-biased

start-up ensure the most demanding digital loads operate reliably. Internal soft start and the ability to track the

output of another supply make the LM3495 versatile and efficient.

Typical Application

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

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

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2006–2007, 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.