LM3478

LM3478-Q1

www.ti.com

SNVS085V – JULY 2000 – REVISED FEBRUARY 2013

High-Efficiency Low-Side N-Channel Controller for Switching Regulator

Check for Samples: LM3478, LM3478-Q1

1

FEATURES

APPLICATIONS

2

•

LM3478Q in VSSOP-8 package is AEC-Q100

•

Distributed Power Systems

qualified and manufactured on an Automotive

•

Battery Chargers

Grade Flow

•

Offline Power Supplies

•

8-lead VSSOP-8 and SOIC-8 packages

•

Telecom Power Supplies

•

Internal push-pull driver with 1A peak current

•

Automotive Power Systems

capability

•

Current limit and thermal shutdown

KEY SPECIFICATIONS

•

Frequency compensation optimized with a

•

Wide supply voltage range of 2.97V to 40V

capacitor and a resistor

•

100kHz to 1MHz Adjustable clock frequency

•

Internal soft start

•

±2.5% (over temperature) internal reference

•

Current Mode Operation

•

10µA shutdown current (over temperature)

•

Undervoltage Lockout with hysteresis

DESCRIPTION

The LM3478 is a versatile Low-Side N-Channel MOSFET controller for switching regulators. It is suitable for use

in topologies requiring a low side MOSFET, such as boost, flyback, SEPIC, etc. Moreover, the LM3478 can be

operated at extremely high switching frequency in order to reduce the overall solution size. The switching

frequency of the LM3478 can be adjusted to any value between 100kHz and 1MHz by using a single external

resistor. Current mode control provides superior bandwidth and transient response, besides cycle-by-cycle

current limiting. Output current can be programmed with a single external resistor.

The LM3478 has built in features such as thermal shutdown, short-circuit protection, over voltage protection, etc.

Power saving shutdown mode reduces the total supply current to 5µA and allows power supply sequencing.

Internal soft-start limits the inrush current at start-up.

Typical Application Circuit

Figure 1. Typical High Efficiency Step-Up (Boost) Converter

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 © 2000–2013, 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.