EC3282|2A, 23V, Synchronous-Rectified  Step-Down  Converter


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2A, 23V, Synchronous-Rectified 

Step-Down  Converter

EC3282

 

 

 

General Description

 

 

 

The ​​ ​​ EC3282 ​​ is ​​ ​​ a ​​ ​​ monolithic ​​ ​​ synchronous ​​ ​​ buck regulator. The  device integrates two  130mΩ MOSFETs, and provides 2A of continuous load current over a wide input voltage of 4.75V to 23V. Current mode control provides fast ​​ transient  response

and ​​ cycle-by-cycle current limit.

An ​​ adjustable ​​ soft-start ​​ prevents ​​ inrush ​​ current ​​ at turn-on, ​​ and ​​ in ​​ shutdown ​​ mode ​​ the ​​ supply current drops to 1µA.

This device,  ​​​​ available in an ​​ ​​ SOP-8 package

provides a very compact solution with minimal external components.

Features

 

 

 

  • 2A Output Current

  • Wide 4.75V to 23V Operating Input Range

  • Integrated 130m Power MOSFET Switches

  • Output Adjustable from 0.923V to 20V

  • Up to 93% Efficiency

 

● ​​ Programmable Soft-Start

● ​​ Stable with Low ESR Ceramic Output Capacitors

● ​​ Fixed 340KHz Frequency

● ​​ Cycle-by-Cycle Over Current Protection

● ​​ Input Under Voltage Lockout

 

 

 

Applications

 

 

Distributed Power Systems

Networking Systems

FPGA, DSP, ASIC Power Supplies

Green Electronics/ Appliances

Notebook Computers

 

 

 

 

 

 

 

Package Types

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1. Package Types of EC3282

2A, 23V, Synchronous-Rectified 

Step-Down  Converter

EC3282

 

 

Pin Configurations

 

 

 

 

Figure 2 Pin Configuration of EC3282(Top View)

 

 

 

Pin Description

 

 

 

 

 

Pin Number

 

 

Pin Name

 

 

Description

 

 

1

 

 

BS

High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel

MOSFET switch. Connect a 0.01µF or greater capacitor from SW to BS to power the high side switch.

 

 

2

 

 

IN

Power Input. IN supplies the power to the IC, as well as the step-down converter switches. Drive IN with a 4.75V to 23V power source. Bypass IN to GND with a suitably large capacitor to eliminate noise on the input to the IC. See Input Capacitor.

 

 

3

 

 

SW

Power Switching Output. SW is the switching node that supplies power to the output. Connect the output LC filter from SW to the output load. Note that a capacitor is required from SW to BS to power the high-side switch.

4

GND

Ground.

 

5

 

FB

Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB

with a resistive voltage divider from the output voltage. The feedback threshold is 0.923V. See Setting the Output Voltage.

 

 

 

6

 

 

 

COMP

Compensation Node. COMP is used to compensate the regulation control loop. Connect a series RC network from COMP to GND to compensate the regulation control ​​ loop. ​​ In ​​ some ​​ cases, ​​ an ​​ additional ​​ capacitor ​​ from ​​ COMP ​​ to ​​ GND ​​ is

required. See Compensation Components.

 

 

7

 

 

EN

Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn on the regulator, drive it low to turn it off. Pull up with 100k resistor for

automatic startup.

 

 

8

 

 

SS

Soft-Start Control Input. SS controls the soft start period. Connect a capacitor from SS

to GND to set the soft-start period. A 0.1µF capacitor sets the soft-start period to 15ms. To disable the soft-start feature, leave SS unconnected.

2A, 23V, Synchronous-Rectified 

Step-Down  Converter

EC3282

 

 

Ordering Information

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Part Number

Package

Marking

Marking Information

EC3282NNM1R

SOP-8L

EC3282

LLLLL

​​ YYWWT

LLLLL is Lot Number

YYWW is date code

T is internal tracking code

Function Block

 

 

 

 

 

Figure 3 Function Block Diagram of EC3282

2A, 23V, Synchronous-Rectified 

Step-Down  Converter

EC3282

 

 

Absolute Maximum Ratings

 

Parameter

Symbol

Value

Unit

Supply Voltage

VIN

-0.3 to 23

V

Switch Node Voltage

VSW

21

V

Boost Voltage

VBS

VSW 0.3V to VSW+6V

V

Output Voltage

VOUT

0.923V to 20

V

All Other Pins

 

–0.3V to +6V

V

Operating Junction Temperature

TJ

150

ºC

Operating Ambient Temperature

TA

-40 to 80

ºC

Storage Temperature

TSTG

-65 to 150

ºC

Lead Temperature (Soldering, 10 sec)

TLEAD

260

ºC

ESD (HBM)

 

1000

V

MSL

 

Level3

 

Thermal Resistance-Junction to Ambient

RθJA

90

ºC / W

Thermal Resistance-Junction to Case

RθJC

45

ºC / W

2A, 23V, Synchronous-Rectified 

Step-Down  Converter

EC3282

 

 

Electrical Characteristics

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

 

 

Parameters

Symbol

Test Condition

Min.

Typ.

Max.

Unit

Shutdown Supply Current

 

VEN = 0V

 

1

3.0

µA

 

Supply Current

 

VEN = 2.0V; VFB =

 

1.0V

 

 

1.3

 

1.5

 

mA

Feedback Voltage

VFB

4.75V VIN ≤ 23V

0.900

0.923

0.946

V

Feedback Overvoltage Threshold

 

 

 

1.1

 

V

Error Amplifier Voltage Gain *

AEA

 

 

400

 

V/V

Error Amplifier Transconductance

GEA

∆IC = ±10µA

 

800

 

µA/V

High-Side Switch On Resistance *

RDS(ON)1

 

 

130

 

m

Low-Side Switch On Resistance *

RDS(ON)2

 

 

130

 

m

High-Side Switch Leakage

 

Current

 

 

VEN = 0V, VSW = 0V

 

 

 

10

 

µA

Upper Switch Current Limit

 

Minimum Duty Cycle

2.4

3.4

 

A

Lower Switch Current Limit

 

From Drain to Source

 

1.1

 

A

COMP to Current Sense

 

Transconductance

 

GCS

 

 

 

 

3.5

 

 

 

A/V

Oscillation Frequency

Fosc1

 

 

340

 

KHz

Short Circuit Oscillation

 

Frequency

 

Fosc2

 

VFB = 0V

 

 

100

 

 

KHz

Maximum Duty Cycle

DMAX

VFB = 1.0V

 

90

 

%

Minimum On Time *

 

 

 

220

 

ns

EN Shutdown Threshold Voltage

 

VEN Rising

1.1

1.5

2.0

V

EN Shutdown Threshold Voltage

 

Hysteresis

 

 

 

 

 

210

 

 

 

mV

EN Lockout Threshold Voltage

 

 

2.2

2.5

2.7

V

EN Lockout Hysteresis

 

 

 

210

 

mV

2A, 23V, Synchronous-Rectified 

Step-Down  Converter

EC3282

 

 

Electrical Characteristics(Cont.)

 

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

 

Parameters

Symbol

Test Condition

Min.

Typ.

Max.

Unit

Input Under Voltage Lockout

Threshold

 

 

VIN Rising

 

3.80

 

4.10

 

4.40

 

V

Input Under Voltage Lockout

Threshold Hysteresis

 

 

 

 

210

 

 

mV

Soft-Start Current

 

VSS = 0V

 

6

 

µA

Soft-Start Period

 

CSS = 0.1µF

 

15

 

ms

Thermal Shutdown *

 

 

 

160

 

°C

 

 

 

Typical Performance Characteristics

 

 

 

 

Figure 4. Steady State Test Figure 5. Startup through ​​ Enable

2A, 23V, Synchronous-Rectified 

Step-Down  Converter

EC3282

 

 

Typical ​​ Performance Characteristics(Cont.)

 

 

 

 ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​​​ 

 

Figure 6. Shutdown ​​ through ​​ Enable  ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​​​ Figure 7. Heavy Load Operation

 

 

 

Figure 8.Medium Load Operation Figure 9.Light Load Operation

2A, 23V, Synchronous-Rectified 

Step-Down  Converter

EC3282

 

 

Typical ​​ Performance Characteristics(Cont.)

 

 

 ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​ ​​​​