LT3579IUFD-1-PBF Просмотр технического описания (PDF) - Linear Technology

Номер в каталоге

Компоненты Описание

производитель

LT3579IUFD-1-PBF

6A Boost/Inverting DC/DC Converter with Fault Protection

Linear Technology 

LT3579/LT3579-1

6A Boost/Inverting

DC/DC Converter with Fault Protection

FEATURES

n 6A, 42V Combined Power Switch

n Output Short Circuit Protection

n Wide Input Range: 2.5V to 16V Operating,

40V Maximum Transient

n LT3579-1: Dual-Phase Capable

n Master/Slave (3.4A/2.6A) Switch Design

n User Configurable Undervoltage Lockout

n Easily Configurable as a Boost, SEPIC, Inverting, or

Flyback Converter

n Low VCESAT Switch: 250mV at 5.5A (Typical)

n Can be Synchronized to External Clock

n Can Synchronize other Switching Regulators

n High Gain SHDN Pin Accepts Slowly Varying Input

Signals

n 20-Lead TSSOP and 20-Pin 4mm × 5mm QFN

Packages

APPLICATIONS

n Local Power Supply

n Vacuum Flourescent Display (VFD) Bias Supplies

n TFT-LCD Bias Supplies

n Automotive Engine Control Unit (ECU) Power

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

Protected by U.S. Patents, including 7579816.

DESCRIPTION

The LT®3579 is a PWM DC/DC converter with built-in fault

protection features to aid in protecting against output shorts,

input/output overvoltage, and overtemperature conditions.

The part consists of a 42V master switch, and a 42V slave switch

that can be tied together for a total current limit of 6A.

The LT3579 is ideal for many local power supply designs. It

can be easily configured in Boost, SEPIC, Inverting, or Flyback

configurations, and is capable of generating 12V at 1.7A, or

–12V at 1.2A from a 5V input. In addition, the LT3579’s slave

switch allows the part to be configured in high voltage, high

power charge pump topologies that are very efficient and

require fewer components than traditional circuits.

The LT3579’s switching frequency range can be set between

200kHz and 2.5MHz. The part may be clocked internally at

a frequency set by the resistor from the RT pin to ground,

or it may be synchronized to an external clock. A buffered

version of the clock signal is driven out of the CLKOUT

pin, and may be used to synchronize other compatible

switching regulator ICs to the LT3579.

The LT3579 also features innovative SHDN pin circuitry that

allows for slowly varying input signals and an adjustable

undervoltage lockout function. Additional features such

as frequency foldback and soft-start are integrated. The

LT3579 is available in 20-lead TSSOP and 20-pin 4mm ×

5mm QFN packages.

TYPICAL APPLICATION

1MHz, 5V to 12V Boost Converter with Output Short Circuit Protection

2.2μH

VIN

5V

SW1 SW2

10μF

130k 6.3k

VIN

22μF 100k FAULT

FB

GATE

200k

LT3579

SHDN

CLKOUT

RT

VC

TEMPERATURE

MONITOR

SYNC GND SS

8k

VOUT

12V

1.7A

10μF

VIN

86.6k

0.1μF

47pF

2.2nF

3579 TA01

Efficiency and Power Loss

100

3.2

90

2.8

80

2.4

70

2.0

60

1.6

50

1.2

40

0.8

30

0.4

20

0

0 0.25 0.5 0.75 1 1.25 1.5 1.75 2

LOAD CURRENT (A)

35791 TA02

35791f

1

Share Link: