IRF IR3820AMTRPbF, IR3820AMPbF Datasheet

01/08/08

1

PD-60330

IR3820AMPbF

HIGHLY INTEGRATED 14A

WIDE-INPUT VOLTAGE, SYNCHRONOUS BUCK REGULATOR

Features

• Wide Input Voltage Range 2.5V to 21V

• Wide Output Voltage Range 0.6V to 12V

• Continuous 14A Load Capability

• 300kHz High Frequency Operation

• Programmable Over-Current Protection

• Programmable PGood Output

• Hiccup Current Limit

• Precision Reference Voltage (0.6V)

• Programmable Soft-Start

• Pre-Bias Start-up

• Thermal Protection

• Thermally Enhanced Package

• Small Size 5mmx6mm QFN

• Pb-Free (RoHS Compliant)

Fig. 1. Typical application diagram

Description

The IR3820A SupIRBuckTMis an easy-to-use,
fully integrated and highly efficient DC/DC
regulator. The onboard switching controller and
MOSFETs make the IR3820A a space-efficient
solution, providing accurate power delivery for
low output voltage applications.

The IR3820A operates from a single 4.5V to 14V
input supply and generates an output voltage
adjustable from 0.6V to 0.75*Vin at loads up to
14A.

A versatile regulator offering programmability of
startup time, power good threshold and current
limit, the IR3820A’s fixed 300kHz switching
frequency allows the use of small external
components.

The IR3820A also features important protection
functions, such as Pre-Bias startup, hiccup
current limit and thermal shutdown to provide the
required system level security in the event of fault
conditions.

Applications

• Distributed Point-of-Loads

• Server and Workstations

• Embedded Systems

• Storage Systems

• DDR Applications

• Graphics Cards

• Game Consoles

• Computing Peripheral Voltage Regulators

SupIRBuck

TM

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PD-60330

IR3820AMPbF

PACKAGE INFORMATION

5mm x 6mm POWER QFN

12

V

IN

11

SW

10

PGnd

15

AGnd

1

23

4

5

6

7

8

9

14

13

Vsns FB COMP AGnd AGnd SS OCSet

PGood

V

CC

V

C

HG

Fig. 2: Package outline (Top view)

W/C2θ

W/C35θ

o

PCBJ

o

JA

=

=

-

ABSOLUTE MAXIMUM RATINGS

(Voltages referenced to GND)

•VINSupply Voltage -0.3V to 24V

• Vcc Supply Voltage -0.3V to 16V

• Vc Supply Voltage -0.3V to 30V

• SW -0.3V to 30V

• PGood -0.3V to 16V

• Fb,COMP,SS,Vsns -0.3V to 3.5V

•OCSet 10mA

• AGnd to PGnd -0.3V to +0.3V

• Storage Temperature Range -65°C To 150°C

• Operating Junction Temperature Range -40°C To 150°C

• ESD Classification JEDEC, JESD22-A114

• Moisture Sensitivity Level JEDEC Level 3 @ 260

o

C

Caution: Stresses beyond those listed under “Absolute Maximum Rating” may cause permanent damage to the

device. These are stress ratings only and functional operation of the device at these or any other conditions beyond
those indicated in the operational sections of the specifications is not implied. Exposure to “Absolute Maximum
Rating” conditions for extended periods may affect device reliability.

4000

PARTS

PER REEL

---------------

PARTS

PER TUBE

15

PIN

COUNT

IR3820AMTRPbF

PACKAGE

DESCRIPTION

M

PKG

DESIG

ORDERING INFORMATION

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PD-60330

IR3820AMPbF

Block Diagram

Fig. 3. Simplified block diagram of the IR3820A.

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PD-60330

IR3820AMPbF

Pin Description

Pin Name Description

1 Vsns PGood sense pin. Use two external resistors to program the power

good threshold.

2 Fb Inverting input to the error amplifier. This pin is connected directly to the

output of the regulator via resistor divider to set the output voltage and
provide feedback to the error amplifier.

3 Comp Output of error amplifier.
4 AGnd Signal ground for internal reference and control circuitry.

5 AGnd Signal ground for internal reference and control circuitry.
6 SS/SD Soft start / shutdown. This pin provides user programmable soft-start

function. Connect an external capacitor from this pin to signal ground
(AGnd) to set the start up time of the output voltage. The converter can
be shutdown by pulling this pin below 0.3V.

7 OCSet Current limit set point. A resistor from this pin to SW pin will set the

current limit threshold.

8

V

CC

This pin provides biasing voltage for the internal blocks of the IC. It also
powers the low side driver. A minimum of 0.1uF, high frequency
capacitor must be connected from this pin to power ground (PGnd).

9 PGood Power Good status pin. Output is open collector. Connect a pull up

resistor from this pin to Vcc.

10 PGnd Power Ground. This pin serves as a separated ground for the MOSFET

drivers and should be connected to the system’s power ground plane.

11 SW Switch node. This pin is connected to the output inductor
12

V

IN

Input vo ltage connection pi n

13 HG This pin is connected to the high side Mosfet gate. Connect a small

capacitor from this pin to switch node (SW).

14

V

C

This pin powers the high side driver and must be connected to a voltage
higher than input voltage. A minimum of 0.1uF high frequency capacitor
must be connected from this pin to the power ground (PGnd).

15 AGnd Signal ground for internal reference and control circuitry.

Pins 4, 5 and 15 need to be connected together on system board.

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PD-60330

IR3820AMPbF

Recommended Operating Conditions

Parameter Symbol Test Condition Min TYP MAX Units

Power Loss

Power Loss

P

loss

Vcc=Vin=12V, Vc=24V, Vo=1.8V,

I

o

=14A, L=1.0uH, Note3

3.7 W

MOSFET R

ds(on)

Top Switch

R

ds(on)_Top

I

D

=13A, Tj(MOSFET)=25oC

6.9

8.7

Bottom Switch R

ds(on)_Bot

I

D

=13A, Tj(MOSFET)=25oC

6.9 8.7

mΩ

Reference Voltage

Feedback Voltage VFB 0.6 V

0oC<Tj<105oC -1.35 +1.35 % Accuracy

-40

o

C<Tj<105oC, Note2

-1.5 +1.5 %

Supply Current

VCC Supply Current (Static)

I

CC(Static)

SS=0V, No Switching 10 13

VC Supply Current
(Static)

I

C(Static)

SS=0V, No Switching 4.5 7

VCC Supply Current
(Dynamic)

I

CC(Dynamic)

SS=3V, Vc=24V, Vcc=Vin=12V.

V

o

=1.8V, Io=0A

15 22

VC Supply Current
(Dynamic)

I

C(Dynamic)

SS=3V, Vc=24V, Vcc=Vin=12V.

V

o

=1.8V, Io=0A

15 22

mA

Under Voltage Lockout

VCC-Start-Threshold VCC_UVLO(R) Supply ramping up 4.0 4.4
VCC-Stop-Threshold VCC_UVLO(F) Supply ramping down 3.7 4.1
VCC-Hysteresis Supply ramping up and down 0.15 0.25 0.3
VC-Start-Threshold VC_UVLO(R)

Supply ramping up 3.1 3.5
VC-Stop-Threshold VC_UVLO(F) Supply ramping down 2.85 3.25
VC-Hysteresis Supply ramping up and down 0.15 0.2 0.25

V

Electrical Specifications

Unless otherwise specified, these specification apply over Vin=Vcc=Vc=12V, 0oC<Tj(Ic)<105oC.
Typical values are specified at T

a

= 25oC.

Symbol Definition Min Max Units

Vin Input Voltage 2.5 21
Vcc Supply Voltage 4.5 14
Vc Supply Voltage Vin + 5V 28
Vo Output Voltage 0.6 12

V

I

o

Note1

Output Current 0 14 A

Tj Junction Temperature -40 125

o

C

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IR3820AMPbF

Note1: Continuous output current determined by input and ou tput voltag e s et ting a nd the the rm al environment.
Note2: Cold temperature performance is guaranteed via correlation using statistical quality control. Not tested in production.
Note3: Guaranteed by Design but not tested in production.

Parameter SYM Test Condition Min TYP MAX Units

Oscillator

Frequency FS

270 300 330 kHz

Ramp Amplitude V

ramp

Note3

1.25 V

Min Pulse Width D

min(ctrl)

Note3

80 ns

Max Duty Cycle D

max

Fb=0V 80 %

Error Amplifier

Input Bias Current I

FB1

SS=3V -0.1 -0.5

Input Bias Current I

FB2

SS=0V 20 35 50

Source/Sink Current I(source/Sink) 50 70 90

μA

Transconductance gm 1000 1300 1600

μmho

Soft Start/SD

Soft Start Current ISS SS=0V 15 20 28

μA

Shutdown Output
Threshold

SD 0.25 V

Power Good

Vsns Low Trip Point Vsns(trip) Vsns Ramping Down 0.35 0.38 0.41 V

Hysteresis PGood(Hys) 15 27.5 40 mV

PGood Output Low
Voltage

PG(voltage) I

PGood

=4mA 0.25 0.5 V

Input Bias Current Isns 0 0.3 1

μA

Over Current Protection

OCSET Current I

OCSET

15 20 26

Hiccup Current I

Hiccup

Note3

3

μA

Hiccup Duty Cycle Hiccup(duty)

I

Hiccup

/ I

SS

,

Note3

15 %

Thermal Shutdown

Thermal Shutdown
Threshold

Note3

140

Thermal Shutdown
Hysteresis

Note3

20

o

C

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IR3820AMPbF

TYPICAL OPERATING CHARACTERISTICS (-40oC - 125oC)

Icc(static)

7.0

8.0

9.0

10.0

11.0

12.0

13.0

-40 -20 0 20 40 60 80 100 120

Temp[oC]

[mA]

Ic(static)

2.0

3.0

4.0

5.0

6.0

7.0

-40 -20 0 20 40 60 80 100 120

Temp[oC]

[mA]

Icc(dynam ic)

13.0

14.0

15.0

16.0

17.0

18.0

19.0

20.0

21.0

22.0

-40-200 20406080100120

Tem p[oC]

[mA]

Ic(dynamic)

13.0

14.0

15.0

16.0

17.0

18.0

19.0

20.0

21.0

22.0

-40 -20 0 20 40 60 80 100 120

Tem p[oC]

[mA]

Vfb

585.0

590.0

595.0

600.0

605.0

-40-200 20406080100120

Temp[oC]

[mV]

ISS

15.0

17.0

19.0

21.0

23.0

25.0

27.0

-40 -20 0 20 40 60 80 100 120

Tem p[oC]

[uA]

Transconductance

1.00

1.05

1.10

1.15

1.20

1.25

1.30

1.35

1.40

1.45

1.50

1.55

1.60

-40-200 20406080100120

Temp[oC]

[mmho]

IOCSET

15.0

16.0

17.0

18.0

19.0

20.0

21.0

22.0

23.0

24.0

25.0

26.0

-40 -20 0 20 40 60 80 100 120

Temp[oC]

[uA]