AiT A7404E6R Schematic [ru]

AiT Semiconductor Inc.

www.ait-ic.com

A7404

DC-DC CONVERTER/BUCK (STEP-DOWN)

42V INPUT STANDOFF VOLTAGE, 0.4A STEP-DOWN CONVERTER

DESCRIPTION

FEATURES

The A7404 is a wide input range, high-efficiency, and
high frequency DC-to-DC step-down switching
regulator, capable of delivering up to 0.4A of output
current. With a fixed switching frequency of 750kHz,
this current mode PWM controlled converter allows
the use of small external components, such as
ceramic input and output caps, as well as small
inductors. A7404 also employs a proprietary control
scheme that switches the device into a power save
mode during light load, thereby extending the range
of high efficiency operation. An OVP function protects
the IC itself and its downstream system against input
voltage surges. With this OVP function, the IC can
stand off input voltage as high as 42V, making it an
ideal solution for industrial applications such as smart
meters as well as automotive applications.
In automotive systems, power comes from the
battery, with its voltage typically between 9V and 24V.
Including cold crank and double battery jump-starts,
the minimum input voltage may be as low as 4V and
the maximum up to 36V, with even higher transient
voltages. With these high input voltages, linear
regulators cannot be used for high supply currents
without overheating the regulator. Instead, high
efficiency switching regulators such as A7404 must
be used to minimize thermal dissipation.

The A7404 is available in SOT-26 package.

ORDERING INFORMATION

Package Type

Part Number

SOT-26

E6

A7404E6R

A7404E6VR

Note

V: Halogen free Package

R: Tape & Reel

AiT provides all RoHS products

Suffix “ V “ means Halogen free Package

 Wide Input Operating Range from 4V to 38V
 Standoff Input Voltage: 42V
 High Efficiency at 20V In 12V Out Up to 95%
 High Efficiency PFM mode at light load
 Capable of Delivering 0.4A of output current.
 No External Compensation Needed
 Current Mode control
 Logic Control Shutdown
 Thermal shutdown and UVLO
 Available in SOT-26 Package

APPLICATION

 Smart Meters
 Industrial Applications
 Automotive Applications

TYPICAL APPLICATION

REV1.0 - DEC 2015 RELEASED - - 1 -

AiT Semiconductor Inc.

www.ait-ic.com

A7404

DC-DC CONVERTER/BUCK (STEP-DOWN)

42V INPUT STANDOFF VOLTAGE, 0.4A STEP-DOWN CONVERTER

PIN DESCRIPTION

Top View

Pin #

Symbol

Function

1

BST

Bootstrap pin. Connect a 10nF capacitor from this pin to SW

2

GND

Ground

3

FB

Feedback Input. Connect an external resistor divider from the output to FB and

GND to set V

OUT

4

EN

Enable pin for the IC. Drive this pin high to enable the part, low to disable.

5

IN

Supply Voltage. Bypass with a 10μF ceramic capacitor to GND

6

SW

Inductor Connection. Connect an inductor Between SW and the regulator output.

REV1.0 - DEC 2015 RELEASED - - 2 -

AiT Semiconductor Inc.

www.ait-ic.com

A7404

DC-DC CONVERTER/BUCK (STEP-DOWN)

42V INPUT STANDOFF VOLTAGE, 0.4A STEP-DOWN CONVERTER

ABSOLUTE MAXIMUM RATINGS

Input Voltage Range

-0.3V~42V

TJ, Max Operating Junction Temperature

150°C

SW, EN Voltage

-0.3V~VIN+0.3V

BST Voltage

-0.3V~SW+6V

FB Voltage

-0.3V~6V

SW to ground current

Internally limited

TO, Operating Temperature

-40°C~85°C

θJC, Package Thermal Resistance

SOT-26

110°C/W

TS, Storage Temperature

-55°C~150°C

Parameter

Conditions

Min.

Typ.

Max.

Unit

Input Standoff Voltage

42

V

Input Voltage Range

4

38

V

Input UVLO

Rising, Hysteresis=140mV

3.80 V

Input OVP

Rising, Hysteresis=1.3V

38 V

Input Supply Current

VFB=0.85V

0.6 mA

Input Shutdown Current

6 μA

FB Feedback Voltage

0.780

0.800

0.820

V

FB Input Current

0.01 μA

Switching Frequency

750

kHz

Maximum Duty Cycle

90 % FoldBack Frequency

VFB=0V

95 kHz

High side Switch On Resistance

ISW=200mA

550 mΩ

High side Switch Current Limit

0.7 A

SW Leakage Current

VIN=12V, VSW=0, EN=GND

10

μA

EN Input Current

VIN=12V, VEN=5V

1 5

μA

EN Input Low Voltage

Rising, Hysteresis=100mV

0.8

1.1

1.4

V

Thermal Shutdown

Hysteresis=40°C

150 °C

Stress beyond above listed “Absolute Maximum Ratings” may lead permanent damage to the device. These are stress ratings only and
operations of the device at these or any other conditions beyond those indicated in the operational sections of the specifications are not
implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

VIN=12V, unless otherwise specified. Typical values are at TA=25°C.

REV1.0 - DEC 2015 RELEASED - - 3 -