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LM3478, LM3478Q-Q1

SNVS085W – JULY 2000 – REVISED DECEMBER 2014

LM3478x/-Q1 High-Efficiency Low-Side N-Channel Controller for Switching Regulator

1 Features

3 Description

The LM3478 is a versatile Low-Side N-Channel

1

•

LM3478Q-Q1 in VSSOP-8 package is AEC-Q100

MOSFET controller for switching regulators. It is

Qualified and Manufactured on an Automotive

suitable for use in topologies requiring a low side

Grade Flow

MOSFET, such as boost, flyback, SEPIC, etc.

•

8-lead VSSOP-8 and SOIC-8 packages

Moreover, the LM3478 can be operated at extremely

high switching frequency in order to reduce the

•

Internal Push-Pull Driver With 1-A Peak Current

overall solution size. The switching frequency of the

Capability

LM3478 can be adjusted to any value between 100

•

Current Limit and Thermal Shutdown

kHz and 1 MHz by using a single external resistor.

•

Frequency Compensation Optimized With a

Current mode control provides superior bandwidth

Capacitor and a Resistor

and

transient

response,

besides

cycle-by-cycle

current limiting. Output current can be programmed

•

Internal Soft Start

with a single external resistor.

•

Current Mode Operation

The LM3478 has built in features such as thermal

•

Undervoltage Lockout With Hysteresis

shutdown,

short-circuit

protection,

over

voltage

protection,

etc.

Power

saving

shutdown

mode

2 Applications

reduces the total supply current to 5 µA and allows

•

Distributed Power Systems

power supply sequencing. Internal soft-start limits the

inrush current at start-up.

•

Battery Chargers

•

Offline Power Supplies

Device Information(1)

•

Telecom Power Supplies

PART NUMBER

PACKAGE

BODY SIZE (NOM)

•

Automotive Power Systems

SOIC (8)

4.90 mm x 3.91 mm

LM3478

•

Wide Supply Voltage Range of 2.97 V to 40 V

VSSOP (8)

3.00 mm x 3.00 mm

•

100-kHz to 1-MHz Adjustable Clock Frequency

LM3478Q-Q1

VSSOP (8)

3.00 mm x 3.00 mm

•

±2.5% (Over Temperature) Internal Reference

(1) For all available packages, see the orderable addendum at

the end of the datasheet.

•

10-µA Shutdown Current (Over Temperature)

Typical High Efficiency Step-Up (Boost) Converter

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.