EC3284S|3A 28V Synchronous Buck Converter


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3A​​ 30V Synchronous Buck Converter

EC3284S

 

General​​ Description

 

The EC3284S is a monolithic synchronous buck regulator. The device integrates 95 mΩ MOSFETS that ​​​​ provide​​ 3A​​ continuous ​​​​ load current over a​​ wide​​ operating​​ input​​ voltage of​​ 4.5V​​ to​​ 30V.Current mode control provides fast transient response​​ and​​ cycle-by-cycle​​ current​​ limit. ​​​​ An adjustable soft-start prevents inrush current at turn on.

Features

 

 ​​​​ 3A Output Current

 ​​​​ Wide​​ 4.5V to​​ 30V Operating Input Range

 ​​​​ Output Adjustable from​​ 0.925V to​​ 0.8VIN

 ​​​​ Up to​​ 93%​​ Efficiency

​​ Programmable Soft-Start

​​ Stable with Low ESR Ceramic Output Capacitors

​​ Fixed 340KHz Frequency

​​ Cycle-by-Cycle Over Current Protection

​​ Short-Circuit Protection

​​ Input Under Voltage Lockout

​​ ​​ Package:SOP 8L(Exposed PAD)

 

 

 

Applications

 

● Distributed Power Systems

● Networking Systems

● FPGA, DSP, ASIC Power Supplies

● Green Electronics/ Appliances

● Notebook Computers

 

 

Pin​​ Configurations

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

0E15N-Rev.F004

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E-CMOS​​ Corp.​​ (www.ecmos.com.tw)

3A​​ 30V Synchronous Buck Converter

EC3284S

 

Typical Applications

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ordering​​ Information

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Part Number

Package

Marking

Marking Information

EC3284SNMHR

SOP 8L

(Exposed Pad)

3284S

LLLLL

​​ YYWWT

LLLLL is Lot Number

YYWW is date code

T is internal tracking code

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3

0E15N-Rev.F004

Page​​ 9​​ of​​ 9

E-CMOS​​ Corp.​​ (www.ecmos.com.tw)

3A​​ 30V Synchronous Buck Converter

EC3284S

 

Function​​ Block​​ ​​ Diagram

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Absolute​​ Maximum​​ Ratings

Parameter

Symbol

Maximum

Units

Supply​​ Voltage

 ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​​​ VIN

-0.3​​ to​​ 30

V

SW​​ Voltage

 ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​​​ VSW

-0.3 to VIN+0.3

V

BS​​ Voltage

 ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​​​ VBS

VSW​​ ​​ 0.3V​​ to​​ VSW+6

V

EN / FB / COMP​​ Voltage

 

-0.3 to 5

V

Continuous SW Current

 

Internally limited

A

Junction to Ambient Thermal Resistance ( θJA​​ )

 

20

°C/W

Junction to Ambient Case Resistance ( θJC​​ )

 ​​ ​​ ​​ ​​ ​​ ​​​​ 

10

°C/W

SOP-8L(EP) Power Dissipation

 

Internal limit

W

Storage Temperature

​​ 

-65 to 150

ºC

Maximum Junction Temperature

 

150

°C

Note:  ​​​​ Exceeding these limits may damage the device. Even the duration of exceeding is very short. Exposure to

absolute maximum rating conditions for long periods may affect device reliability。

 

 

3

0E15N-Rev.F004

Page​​ 9​​ of​​ 9

E-CMOS​​ Corp.​​ (www.ecmos.com.tw)

3A​​ 30V Synchronous Buck Converter

EC3284S

 

 

Recommended Operating Conditions

 

Parameter

Symbol

Value

Units

Supply Input Voltage

VIN

4.5 to +30

V

Operating Junction Temperature

TJ

-40 to +125

°C

 

 

 

 

 

 

 

 

Electrical Characteristics

(VIN​​ =​​ 12V,​​ TJ​​ =​​ 25​​ unless​​ otherwise​​ specified.)

Parameter

Symbol

Conditions

Min

Typ

Max

Unit

Feedback Voltage

VFB

4.5V  VIN  30V

0.9

0.925

0.95

V

Feedback Overvoltage Threshold

 

 

 

1.1

 

V

High-Side Switch-On Resistance*

 

 

 

90

 

mΩ

Low-Side Switch-On Resistance*

 

 

 

70

 

mΩ

High-Side Switch Leakage

 

VEN VSW 0V

,

0.1

10

uA

Upper Switch Current Limit*

 

Min Duty Cycle

3.8

4.5

 

A

Lower Switch Current Limit*

 

From Drain to

 ​​ ​​ ​​​​ Source

 

1.2

 

A

COMP to Current Limit Trans conductance

GCOMP

 

 

5.2

 

A/V

Error Amplifier Trans conductance

GEA

ΔICOMP = ±10uA

 

900

 

uA/V

Error Amplifier DC Gain*A

VEA

 

 

400

 

V/V

Switching Frequency

fSW

 

300

340

380

KHz

Short Circuit Switching Frequency

 

VFB​​  = 0V

 

100

 

KHz

Minimum Duty Cycle

DMIN

 

7.5

​​ 

 

%

Maximum Duty Cycle

DMAX

 

​​ 

​​ 92

 

%

EN Shutdown Threshold Voltage

 

VEN​​  Rising

1.1

1.4

2

V

EN Shutdown Threshold Voltage Hysteresis

 

 

 

180

 

mV

EN Lockout Threshold Voltage

 

 

2.2

2.5

2.7

V

EN Lockout Hysteresis

 

 

 

150

 

mV

Supply Current in Shutdown

 

VEN​​  = 0V

 

0.3

3.0

uA

IC Supply Current in Operation

 

VEN 3V, VFB=1V

 

1.3

1.5

mA

Input UVLO Threshold Rising

UVLO

VEN ​​  Rising

3.8

4.0​​ 

4.4

V

Input UVLO Threshold Hysteresis

 

 

 

150

 

mV

Soft-start Current

 

VSS 0V

 

6

 

uA

Soft-start Period

 

CSS =0.1uF

 

15

 

mS

Thermal Shutdown Temperature*

 

Hysteresis=25°C

 

155

 

 

Note: * Guaranteed by design, not tested

 

 

 

 

 

 

Typical Applications

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

EC3284S Circuit, 3.3V/3A output