Datasheet LM2576T-12-V, LM2576T-12-H, LM2576T-12, LM2576T-5-V, LM2576T-5-H Datasheet (Semtech Corporation)

1 www.semtech.com

LM2575 & LM2576

1A & 3A Miniconverter

Switching Regulators

POWER MANAGEMENT

Revision 1, January 2001

u Pin for pin replacement for Nationals LM2575/6

series

u DC-to-DC buck or buck/boost converter requiring

only 4 support components

u Fixed or adjustable voltages
u Preset output voltages of 3.3V, 5V and 12V
u Wide output voltage range, 1.23V to 35V
u 82% typical efficiency @ 5V out
u Wide input voltage range, 4V to 40V
u Inhibit/enable control pin
u Industrial temperature range
u TO-220 and TO-263 packages

The LM2575/6 series switching regulators are monolithic
integrated circuits designed for use in buck or buck/
boost regulator applications requiring accurate output
voltages over combined variations of line, load and
temperature. This unique series greatly simplifies
switching power supply design. The LM2575 has a
maximum output current of 1A and the LM2576 is rated
for 3A.

The LM2575/6 series miniconverters include a
switching regulator and compensation network all within
the same package. Just add a choke, catch diode and
two capacitors to obtain an efficient DC-to-DC converter.
The current limit and thermal shutdown features of the
LM2575/6 series fully protect the device against
overstress conditions.

The LM2575/6 series offers an alternative to popular 3
terminal linear regulators by providing higher efficiency
with reduced heatsink size. In many applications a heat
sink will not be required.

u Micro controller power supplies
u Medical equipment
u Industrial power supplies
u Instrumentation power supplies

Description Features

Applications

Typical Application Circuits

5752ML6752ML

L

1

Hµ033Hµ001

D

1

A3A7

C

NI

Fµ86Fµ021

C

TUO

Fµ033Fµ000,1

2ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

retemaraPlobmySmumixaMstinU

egatloVtupnIV

NI

54V

egatloVtupnIniPffO/nOV

FFO/NO

3.0- £ V

FFO/NO

£ V

NI

V

)etatSydaetS(nommoCotegatloVtuptuO 1-V

noitapissiDrewoPP

D

detimiLyllanretnIW

tneibmAotnoitcnuJecnatsiseRlamrehT
022-OT
362-OT

q

AJ

55
06

W/C°

esaCotnoitcnuJecnatsiseRlamrehT
022-OT
362-OT

q

CJ

0.2

0.2

W/C°

egnaRerutarepmeTnoitcnuJgnitarepOT

J

521+ot04-C°

egnaRerutarepmeTegarotST

GTS

051+ot56-C°

.ceS01)gniredloS(erutarepmeTdaeLT

DAEL

003C°

)ledoMydoBnamuH(gnitaRDSEV

DSE

2Vk

retemaraPlobmySsnoitidnoCtseTniMpyTxaMstinU

egatloVtuptuOV

O

I

O

A5.0=32.303.373.3V

3.3-6752MLVotV8

NI

detaR02.304.3

41.374.3

egatloVtuptuOV

O

I

O

A5.0=09.400.501.5V

5-6752MLVotV8

NI

detaR58.451.5

57.452.5

egatloVtuptuOV

O

I

O

A5.0=67.1100.2142.21V

21-6752MLVotV51

NI

detaR25.1184.21

04.1106.21

egatloVkcabdeeFV

BF

I

O

A5.0=712.1032.1342.1V

V,JDA-6752ML

O

V5=VotV8

NI

detaR391.1762.1

081.1082.1

tnerruCsaiBkcabdeeFI

B

V

NI

I,V21=

O

A5.0=05001An

JDA-6752ML 005

Unless otherwise specified: VIN = 12V for 3.3V, 5V and ADJ options and 25V for 12V option; V

OUT

= 5V for ADJ option; TA = 25ºC; VIN rated = 40V;

IO = 0.5 to 3A (LM2576), 0.2 to 1A (LM2575). Values in bold apply over full operating temperature range.

Absolute Maximum Ratings

Electrical Characteristics

3ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Electrical Characteristics (Cont.)

retemaraPlobmySsnoitidnoCtseTniMpyTxaMstinU

egatloVtuptuOV

O

I

O

A2.0=32.303.373.3V

3.3-5752MLVotV8

NI

detaR02.304.3

41.374.3

egatloVtuptuOV

O

I

O

A2.0=09.400.501.5V

5-5752MLVotV8

NI

detaR58.451.5

57.452.5

egatloVtuptuOV

O

I

O

A2.0=67.1100.2142.21V

21-5752MLVotV51

NI

detaR25.1184.21

04.1106.21

egatloVkcabdeeFV

BF

I

O

A2.0=712.1032.1342.1V

V,JDA-5752ML

O

V5=VotV8

NI

detaR391.1762.1

081.1082.1

tnerruCsaiBkcabdeeFI

B

V

NI

I,V21=

O

A2.0=05001An

JDA-5752ML 005

noitpO/ycneiciffE

V3.3

h

V

NI

I,V21=

O

)6752MLrofA3,5752ML(A1=77

%

V5 28

V21V

NI

I,V51=

O

)6752MLrofA3,5752ML(A1=88

V,JDA

O

V5=V

NI

I,V21=

O

)6752MLrofA3,5752ML(A1=28

ycneuqerFgnihctiwSf

XS

742585

zHk

3426

egatloVnoitarutaS

)1(

V

TAS

I,5752ML

O

A1= 9.02.1

V

I,6752ML

O

A3= 9.04.1

)nO(elcyCytuD.xaM

)3(

CD3989

%

5752MLtnerruCkaeP

)1(

I

LC

7.12.20.3

A

3.12.3

6752MLtnerruCkaeP

)1(

I

LC

2.48.59.6

A

5.35.7

Unless otherwise specified: VIN = 12V for 3.3V, 5V and ADJ options and 25V for 12V option; V

OUT

= 5V for ADJ option; TA = 25ºC; VIN rated = 40V;

IO = 0.5 to 3A (LM2576), 0.2 to 1A (LM2575). Values in bold apply over full operating temperature range.

4ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Notes:

(1) Output sourcing current, resistive load, no inductor or capacitor.
(2) Feedback = VO + 1.0V.
(3) Feedback = 0V.

Electrical Characteristics (Cont.)

retemaraPlobmySsnoitidnoCtseTniMpyTxaMstinU

tnerruCegakaeLtuptuO

)2(

V0=tuptuOI

L

VNIV=

NI

detaR2

Am

V1-=tuptuO 5.703

tnerruCtnecseiuQ

)2(

I

Q

501Am

21

tnerruCtnecseiuQybdnatSI

YBTS

05Aµ

)V5=niPffO/nO( 005

leveLtupnIcigoLniPffO/nOV

HI

2.24.1V

4.2

V

LI

2.10.1

V

8.0

tnerruCtupnIniPffO/nOI

HI

V

FFO/NO

)ffO(V5=2103Aµ

I

LI

V

FFO/NO

)nO(V0=001

Unless otherwise specified: VIN = 12V for 3.3V, 5V and ADJ options and 25V for 12V option; V

OUT

= 5V for ADJ option; TA = 25ºC; VIN rated = 40V;

IO = 0.5 to 3A (LM2576), 0.2 to 1A (LM2575). Values in bold apply over full operating temperature range.

5ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

TO-220-5

TO-263-5

eciveD

)1(

egakcaPtnerruC

XX-T5752ML5-022-OT

)3()2(

A1

RT.XX-S5752ML5-362-OT

)4(

XX-T6752ML5-022-OT

)3()2(

A3

RT.XX-S6752ML5-362-OT

)4(

Notes:

(1) -XX = Voltage Option. Available voltages are 3.3V
(-3.3), 5V (-5.0), 12V (-12), and ADJ (-ADJ), which is
adjustable between 1.23V and 35V.
(2) Lead bend options for TO-220-5 are: T-XX = Straight
in-line; T-XX-V = Vertical Staggered; T-XX-H = Horizontal
Staggered. Please refer to outline drawings at the end of
this datasheet.
(3) Only available in tube packaging. A tube contains 50
devices.
(4) Only available in tape and reel packaging. A reel
contains 800 devices.

6752ML,5752ML

niPnoitcnuF

1V

NI

2TUPTUO

3NOMMOC

4KCABDEEF

5FFO/NO

NOMMOCsiBAT

Pin Configurations Ordering Information

Block Diagram

6ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Typical Characteristics - LM2575

7ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Typical Characteristics - LM2575 (Cont.)

8ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Typical Characteristics - LM2575 (Cont.)

9ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Typical Characteristics - LM2576

10ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Typical Characteristics - LM2576 (Cont.)

11ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Typical Characteristics - LM2576 (Cont.)

12ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

The above component selections will be adequate for
most applications for output currents from 250mA to 3A
(LM2576) or 150mA to 1A (LM2575). Applications with
V

OUT

below 5V or above 24V may require component
adjustment for maximum performance; please contact
factory for application assistance.

1. Device Selection. Select an appropriate device from
the Ordering Information guide based upon voltage
option and package.

2. Thermal Conditions. Most applications will not require
a heatsink for the TO-220 package. Approximate power
dissipation is:

IN

O

IN

IN

SATOO

V

V

V02.0

V

VIV

P +=

3. Catch Diode. If the output must be capable of a
sustained short, the IF rating must be above 3A for the
LM2575 and 7A for the LM2576. The use of an ultra
fast diode with soft recovery characteristics or a Schottky
will be adequate. The major impact on the selection of a

Schottky versus an ultra fast diode is efficiency. Schottkys
will provide approximately 4% to 5% improvement for
V

OUTS

below 12V, whereas above 12V the difference will
become less significant. Breakdown rating must be in
excess of VIN for margin.

4. Input Capacitor. The value shown will be adequate for
most applications. Ripple voltage at the switching
frequency is caused by the input capacitor supplying load
current during the on time of the power switch. The use
of a low ESR switching type capacitor will minimize ripple
to an acceptable level.

5. Layout. Use short connections with a central point
ground to prevent improper operation caused by stray
inductance and ground loops.

6. Output Capacitor. Ripple voltage on V

OUT

is directly

related to the value of C

OUT

and the internal resistance

ESR of C

OUT

. Output noise can be lowered by increasing

C

OUT

or by selecting a capacitor with a lower ESR. ESR
must be a minimum of 0.03W for the LM2576 or 0.07W
for the LM2575 to maintain stability, otherwise raise the
value of C

OUT

.

Applications Information - Buck Mode

5752ML6752ML

L

1

Hµ033Hµ001

D

1

A3A7

C

NI

Fµ86Fµ021

C

TUO

Fµ033Fµ000,1

13ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

7. Switching Spikes. Switching spikes will also occur due
to distributive capacitance across turns of the inductor
when combined with output capacitor series inductance
(ESL). Reduction to a level at or below the switching ripple
can be achieved by using a post filter as shown below.

Switching Spike Reduction

Typical Buck Shutdown

Applications Information (Cont.)

14ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Turn-On Delay

Under Voltage Lockout

Turn-On Delay With Spike Filter

Applications Information (Cont.)

15ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

5752ML6752ML

C

NI

Fµ74Fµ001

1D A3A7

1L Hµ001Hµ86

C

TUO

Fµ007,2Fµ008,6

I

TUO

Am052Am005

5752ML6752ML

C

NI

Fµ74Fµ001

1D A3A7

1L Hµ001Hµ86

C

TUO

Fµ074Fµ007,2

I

TUO

Am001Am057

Inverting buck/boost operation is a different topology of
operation than buck. This difference reduces the output
current capability of the device, in that the inductor must
supply all of the load current during the time the power
switch is off. Maximum output current is approximately:

)2576LM(

V

V

12

5.3

I

IN

O

OUT































+

≈

)2575LM(

V

V

12

3.1

I

IN

O

OUT































+

≈

Component stress requirements are very similar to the
buck with a few exceptions:

(1) catch diode breakdown VBR must be greater than
VIN + |V

OUT

|

(2) input capacitor is larger due to the increased peak
current during switch turn on. Power dissipation is
approximately:

IN

O

INSAT

IN

O

O

INO

O

D

V

V

V02.0V

V

V

1I

VV

V

P +















+















+

≈

Please contact factory for additional assistance when
using the buck/boost topology.

Applications Information - Inverting Buck/Boost

16ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Inverting Buck/Boost Shutdown

Applications Information (Cont.)

17ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Pre-Wound Inductors:

Hurricane Electronics Lab
P.O. Box 1280
Hurricane Industrial Park
Hurricane, UT 84737
[phone]

Core Source:

Micro Metals, Inc.
1190 N. Hawk Circle
Anaheim, CA 92807
[phone]

Capacitors:

VPR Series
Mallory Capacitor Co.
4760 Kentucky Avenue
Indianapolis, IN 46241
[phone]

511D & 673 Series
Sprague Electric Co.
North Adams, MA
[phone]

HFQ, HFZ Series
Panasonic Industrial Co.
2 Panasonic Way
Secaucus, NJ 07094
[phone]

PF, PL Series
Nichicon Corp.
927 E. State Pkwy.
Schaumburg, IL 60195
[phone]

LXF Series
United Chemi-con
9801 West Higgins Road
Rosemont, IL 60018
[phone]

Heat Sinks:

AAVID Engineering Co.
P.O.Box 400
One Kool Path
Laconia, NH 03247
[phone]

Thermalloy, Inc.
2021 W. Valley View Lane
Dallas, TX 76381
[phone]

Diodes - Catch:

Ultra Fast/Soft Recovery
Semtech Corporation
652 Mitchell Road
Newbury Park, CA 91320
[phone]

Diodes - Schottky:

Fuji/Collmer Semiconductor
14368 Proton Road
Dallas, TX 76244
[phone]

Micro Quality
1000 N. Shiloh
Garland, TX 76046
[phone]

Support Components Information

18ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Outline Drawing - TO-220-5 (T-XX-H Option)

Outline Drawing - TO-220-5 (T-XX Option)

Outline Drawing - TO-220-5 (T-XX-V Option)

19ã 2001 Semtech Corp. www.semtech.com

LM2575 & LM2576

POWER MANAGEMENT

Contact Information

Semtech Corporation

Power Management Products Division

652 Mitchell Rd., Newbury Park, CA 91320

Phone: [phone] FAX [phone]

Outline Drawing - TO-263-5

Minimum Land Pattern - TO-263-5