National Semiconductor [object Object], LM2575-3.3, LM1575-3.3, LM2575HV-3.3, LM1575-5.0 Series Manual

LM1575/LM2575/LM2575HV
SIMPLE SWITCHER

®

1A Step-Down Voltage Regulator

LM1575/LM2575/LM2575HV Series SIMPLE SWITCHER 1A Step-Down Voltage Regulator

August 2004

General Description

The LM2575 series of regulators are monolithic integrated
circuits that provide all the active functions for a step-down
(buck) switching regulator, capable of driving a 1A load with
excellent line and load regulation. These devices are avail­able in fixed output voltages of 3.3V, 5V, 12V, 15V, and an
adjustable output version.

Requiring a minimum number of external components, these
regulators are simple to use and include internal frequency
compensation and a fixed-frequency oscillator.

The LM2575 series offers a high-efficiency replacement for
popular three-terminal linear regulators. It substantially re­duces the size of the heat sink, and in many cases no heat
sink is required.

A standard series of inductors optimized for use with the
LM2575 are available from several different manufacturers.
This feature greatly simplifies the design of switch-mode
power supplies.

±

Other features include a guaranteed
put voltage within specified input voltages and output load
conditions, and
shutdown is included, featuring 50 µA (typical) standby cur­rent. The output switch includes cycle-by-cycle current limit­ing, as well as thermal shutdown for full protection under
fault conditions.

±

10% on the oscillator frequency. External

4% tolerance on out-

Features

n 3.3V, 5V, 12V, 15V, and adjustable output versions
n Adjustable version output voltage range,

1.23V to 37V (57V for HV version)
line and load conditions

n Guaranteed 1A output current
n Wide input voltage range, 40V up to 60V for HV version
n Requires only 4 external components
n 52 kHz fixed frequency internal oscillator
n TTL shutdown capability, low power standby mode
n High efficiency
n Uses readily available standard inductors
n Thermal shutdown and current limit protection

+

n P

Product Enhancement tested

±

4% max over

Applications

n Simple high-efficiency step-down (buck) regulator
n Efficient pre-regulator for linear regulators
n On-card switching regulators
n Positive to negative converter (Buck-Boost)

Typical Application (Fixed Output Voltage

Versions)

Note: Pin numbers are for the TO-220 package.

01147501

SIMPLE SWITCHER®is a registered trademark of National Semiconductor Corporation.

© 2004 National Semiconductor Corporation DS011475 www.national.com

Block Diagram and Typical Application

LM1575/LM2575/LM2575HV

3.3V, R2 = 1.7k

5V, R2 = 3.1k

12V, R2 = 8.84k

15V, R2 = 11.3k

For ADJ. Version

R1 = Open, R2 = 0Ω

Note: Pin numbers are for the TO-220 package.

Connection Diagrams

number.)

Straight Leads

5–Lead TO-220 (T)

01147522

Top View

LM2575T-XX or LM2575HVT-XX

See NS Package Number T05A

01147502

FIGURE 1.

(XX indicates output voltage option. See Ordering Information table for complete part

Bent, Staggered Leads

5-Lead TO-220 (T)

01147524

Top View

01147523

Side View
LM2575T-XX Flow LB03 or
LM2575HVT-XX Flow LB03

See NS Package Number T05D

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Connection Diagrams (XX indicates output voltage option. See Ordering Information table for complete part

number.) (Continued)

16–Lead DIP (N or J) 24-Lead Surface Mount (M)

LM1575/LM2575/LM2575HV

*No Internal Connection

Top View

LM2575N-XX or LM2575HVN-XX

See NS Package Number N16A

LM1575J-XX-QML

See NS Package Number J16A

01147525

01147526

*No Internal Connection

Top View

LM2575M-XX or LM2575HVM-XX

See NS Package Number M24B

TO-263(S)

5-Lead Surface-Mount Package

Top View

01147529

Side View

01147530

LM2575S-XX or LM2575HVS-XX
See NS Package Number TS5B

Ordering Information

Package NSC Standard High Temperature

Type Package Voltage Rating Voltage Rating Range

Number (40V) (60V)

5-Lead TO-220 T05A LM2575T-3.3 LM2575HVT-3.3

Straight Leads LM2575T-5.0 LM2575HVT-5.0

LM2575T-12 LM2575HVT-12

LM2575T-15 LM2575HVT-15

LM2575T-ADJ LM2575HVT-ADJ

5-Lead TO-220 T05D LM2575T-3.3 Flow LB03 LM2575HVT-3.3 Flow LB03

Bent and LM2575T-5.0 Flow LB03 LM2575HVT-5.0 Flow LB03

Staggered Leads LM2575T-12 Flow LB03 LM2575HVT-12 Flow LB03

LM2575T-15 Flow LB03 LM2575HVT-15 Flow LB03

LM2575T-ADJ Flow LB03 LM2575HVT-ADJ Flow LB03

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Ordering Information (Continued)

Package NSC Standard High Temperature

Type Package Voltage Rating Voltage Rating Range

Number (40V) (60V)

16-Pin Molded N16A LM2575N-5.0 LM2575HVN-5.0 −40˚C ≤ T

DIP LM2575N-12 LM2575HVN-12

LM2575N-15 LM2575HVN-15

LM2575N-ADJ LM2575HVN-ADJ

24-Pin M24B LM2575M-5.0 LM2575HVM-5.0

LM1575/LM2575/LM2575HV

Surface Mount LM2575M-12 LM2575HVM-12

LM2575M-15 LM2575HVM-15

LM2575M-ADJ LM2575HVM-ADJ

5-Lead TO-263 TS5B LM2575S-3.3 LM2575HVS-3.3

Surface Mount LM2575S-5.0 LM2575HVS-5.0

LM2575S-12 LM2575HVS-12

LM2575S-15 LM2575HVS-15

LM2575S-ADJ LM2575HVS-ADJ

16-Pin Ceramic J16A LM1575J-3.3-QML

DIP LM1575J-5.0-QML

LM1575J-12-QML −55˚C ≤ T

LM1575J-15-QML

LM1575J-ADJ-QML

≤ +125˚C

J

≤ +150˚C

J

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LM1575/LM2575/LM2575HV

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Minimum ESD Rating

(C = 100 pF, R = 1.5 kΩ)2kV

Lead Temperature

(Soldering, 10 sec.) 260˚C

Maximum Supply Voltage

LM1575/LM2575 45V

Operating Ratings

LM2575HV 63V

ON /OFF Pin Input Voltage

−0.3V ≤ V ≤ +V

Output Voltage to Ground

(Steady State) −1V

Power Dissipation Internally Limited

Storage Temperature Range −65˚C to +150˚C

Maximum Junction Temperature 150˚C

IN

Temperature Range

LM1575 −55˚C ≤ T

LM2575/LM2575HV −40˚C ≤ T

≤ +150˚C

J

≤ +125˚C

J

Supply Voltage

LM1575/LM2575 40V

LM2575HV 60V

LM1575-3.3, LM2575-3.3, LM2575HV-3.3 Electrical Characteristics

Specifications with standard type face are for TJ= 25˚C, and those with boldface type apply over full Operating Tempera­ture Range .

Symbol Parameter Conditions Typ LM1575-3.3 LM2575-3.3 Units

(Limits)

SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2

V

OUT

Output Voltage VIN= 12V, I

LOAD

Circuit of Figure 2 3.267 3.234 V(Min)

V

OUT

Output Voltage 4.75V ≤ VIN≤ 40V, 0.2A ≤ I

LM1575/LM2575 Circuit of Figure 2 3.200/3.168 3.168/3.135 V(Min)

V

OUT

Output Voltage 4.75V ≤ VIN≤ 60V, 0.2A ≤ I

LM2575HV Circuit of Figure 2 3.200/3.168 3.168/3.135 V(Min)

η Efficiency V

= 12V, I

IN

LOAD

LM2575HV-3.3

Limit Limit

(Note 2) (Note 3)

= 0.2A 3.3 V

3.333 3.366 V(Max)

≤ 1A 3.3 V

LOAD

3.400/3.432 3.432/3.465 V(Max)

≤ 1A 3.3 V

LOAD

3.416/3.450 3.450/3.482 V(Max)

=1A 75 %

LM1575-5.0, LM2575-5.0, LM2575HV-5.0 Electrical Characteristics

Specifications with standard type face are for TJ= 25˚C, and those with boldface type apply over full Operating Tempera­ture Range.

Symbol Parameter Conditions Typ LM1575-5.0 LM2575-5.0 Units

(Limits)

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SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2

V

OUT

Output Voltage VIN= 12V, I

LOAD

Circuit of Figure 2 4.950 4.900 V(Min)

V

OUT

Output Voltage 0.2A ≤ I

LM1575/LM2575 8V ≤ V

≤ 1A, 5.0 V

LOAD

≤ 40V 4.850/4.800 4.800/4.750 V(Min)

IN

Circuit of Figure 2 5.150/5.200 5.200/5.250 V(Max)

V

OUT

Output Voltage 0.2A ≤ I

LM2575HV 8V ≤ V

≤ 1A, 5.0 V

LOAD

≤ 60V 4.850/4.800 4.800/4.750 V(Min)

IN

Circuit of Figure 2 5.175/5.225 5.225/5.275 V(Max)

LM2575HV-5.0

Limit Limit

(Note 2) (Note 3)

= 0.2A 5.0 V

5.050 5.100 V(Max)

LM1575-5.0, LM2575-5.0, LM2575HV-5.0

= 12V, I

IN

(Continued)

=1A 77 %

LOAD

LM2575HV-5.0

Limit Limit

(Note 2) (Note 3)

Electrical Characteristics

Specifications with standard type face are for TJ= 25˚C, and those with boldface type apply over full Operating Tempera­ture Range.

Symbol Parameter Conditions Typ LM1575-5.0 LM2575-5.0 Units

η Efficiency V

LM1575/LM2575/LM2575HV

LM1575-12, LM2575-12, LM2575HV-12 Electrical Characteristics

Specifications with standard type face are for TJ= 25˚C, and those with boldface type apply over full Operating Tempera­ture Range .

Symbol Parameter Conditions Typ LM1575-12 LM2575-12 Units

LM2575HV-12

Limit Limit

(Note 2) (Note 3)

SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2

V

OUT

V

OUT

Output Voltage VIN= 25V, I

Output Voltage 0.2A ≤ I

LM1575/LM2575 15V ≤ V

V

OUT

Output Voltage 0.2A ≤ I

LM2575HV 15V ≤ V

η Efficiency V

Circuit of Figure 2 11.88 11.76 V(Min)

LOAD

IN

Circuit of Figure 2 12.36/12.48 12.48/12.60 V(Max)

LOAD

IN

Circuit of Figure 2 12.42/12.54 12.54/12.66 V(Max)

= 15V, I

IN

= 0.2A 12 V

LOAD

12.12 12.24 V(Max)

≤ 1A, 12 V

≤ 40V 11.64/11.52 11.52/11.40 V(Min)

≤ 1A, 12 V

≤ 60V 11.64/11.52 11.52/11.40 V(Min)

=1A 88 %

LOAD

(Limits)

(Limits)

LM1575-15, LM2575-15, LM2575HV-15 Electrical Characteristics

Specifications with standard type face are for TJ= 25˚C, and those with boldface type apply over full Operating Tempera­ture Range .

Symbol Parameter Conditions Typ LM1575-15 LM2575-15 Units

(Limits)

SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2

V

OUT

Output Voltage VIN= 30V, I

LOAD

Circuit of Figure 2 14.85 14.70 V(Min)

V

OUT

Output Voltage 0.2A ≤ I

LM1575/LM2575 18V ≤ V

≤ 1A, 15 V

LOAD

≤ 40V 14.55/14.40 14.40/14.25 V(Min)

IN

Circuit of Figure 2 15.45/15.60 15.60/15.75 V(Max)

V

OUT

Output Voltage 0.2A ≤ I

LM2575HV 18V ≤ V

≤ 1A, 15 V

LOAD

≤ 60V 14.55/14.40 14.40/14.25 V(Min)

IN

Circuit of Figure 2 15.525/15.675 15.68/15.83 V(Max)

η Efficiency V

= 18V, I

IN

LOAD

LM2575HV-15

Limit Limit

(Note 2) (Note 3)

= 0.2A 15 V

15.15 15.30 V(Max)

=1A 88 %

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LM1575-ADJ, LM2575-ADJ, LM2575HV-ADJ Electrical Characteristics

Specifications with standard type face are for TJ= 25˚C, and those with boldface type apply over full Operating Temperature
Range.

Symbol Parameter Conditions Typ LM1575-ADJ LM2575-ADJ Units

LM2575HV-ADJ

(Limits)

Limit Limit

(Note 2) (Note 3)

SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2

V

OUT

Feedback Voltage VIN= 12V, I

V

= 5V 1.217 1.217 V(Min)

OUT

= 0.2A 1.230 V

LOAD

Circuit of Figure 2 1.243 1.243 V(Max)

V

OUT

V

OUT

η Efficiency V

Feedback Voltage 0.2A ≤ I

LM1575/LM2575 8V ≤ V

V

OUT

Feedback Voltage 0.2A ≤ I

LM2575HV 8V ≤ V

V

OUT

= 12V, I

IN

≤ 1A, 1.230 V

LOAD

≤ 40V 1.205/1.193 1.193/1.180 V(Min)

IN

= 5V, Circuit of Figure 2 1.255/1.267 1.267/1.280 V(Max)

≤ 1A, 1.230 V

LOAD

≤ 60V 1.205/1.193 1.193/1.180 V(Min)

IN

= 5V, Circuit of Figure 2 1.261/1.273 1.273/1.286 V(Max)

LOAD

= 1A, V

=5V 77 %

OUT

All Output Voltage Versions Electrical Characteristics

Specifications with standard type face are for TJ= 25˚C, and those with boldface type apply over full Operating Tempera­ture Range. Unless otherwise specified, V

and V

= 30V for the 15V version. I

IN

LOAD

Symbol Parameter Conditions Typ LM1575-XX LM2575-XX Units

DEVICE PARAMETERS

I

b

f

O

V

SAT

Feedback Bias Current V

OUT

Oscillator Frequency (Note 13) 52 kHz

Saturation Voltage I

OUT

DC Max Duty Cycle (ON) (Note 6) 98 %

I

CL

I

L

Current Limit Peak Current (Notes 5, 13) 2.2 A

Output Leakage (Notes 7, 8) Output = 0V 2 2 mA(Max)

Current Output = −1V 7.5 mA

I

Q

I

STBY

Quiescent Current (Note 7) 5 mA

Standby Quiescent ON /OFF Pin = 5V (OFF) 50 µA

Current 200/500 200 µA(Max)

= 12V for the 3.3V, 5V, and Adjustable version, VIN= 25V for the 12V version,

IN

= 200 mA.

LM2575HV-XX

(Limits)

Limit Limit

(Note 2) (Note 3)

= 5V (Adjustable Version Only) 50 100/500 100/500 nA

47/43 47/42 kHz(Min)

58/62 58/63 kHz(Max)

= 1A (Note 5) 0.9 V

1.2/1.4 1.2/1.4 V(Max)

93 93 %(Min)

1.7/1.3 1.7/1.3 A(Min)

3.0/3.2 3.0/3.2 A(Max)

Output = −1V 30 30 mA(Max)

10/12 10 mA(Max)

LM1575/LM2575/LM2575HV

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All Output Voltage Versions
Electrical Characteristics

Specifications with standard type face are for TJ= 25˚C, and those with boldface type apply over full Operating Tempera­ture Range. Unless otherwise specified, V

and V

Symbol Parameter Conditions Typ LM1575-XX LM2575-XX Units

LM1575/LM2575/LM2575HV

DEVICE PARAMETERS

θ

JA

θ

JA

θ

JC

θ

JA

θ

JA

θ

JA

ON /OFF CONTROL Test Circuit Figure 2

V

IH

V

IL

I

IH

I

IL

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.

Note 2: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All limits are used to calculate Average
Outgoing Quality Level, and all are 100% production tested.

Note 3: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits are 100%
production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods.

Note 4: External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the
LM1575/LM2575 is used as shown in the Figure 2 test circuit, system performance will be as shown in system parameters section of Electrical Characteristics.

Note 5: Output (pin 2) sourcing current. No diode, inductor or capacitor connected to output pin.

Note 6: Feedback (pin 4) removed from output and connected to 0V.

Note 7: Feedback (pin 4) removed from output and connected to +12V for the Adjustable, 3.3V, and 5V versions, and +25V for the 12V and 15V versions, to force

the output transistor OFF.

Note 8: V

Note 9: Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with

board with minimum copper area.

Note 10: Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with
containing approximately 4 square inches of copper area surrounding the leads.

Note 11: Junction to ambient thermal resistance with approximately 1 square inch of pc board copper surrounding the leads. Additional copper area will lower
thermal resistance further. See thermal model in Switchers made Simple software.

Note 12: If the TO-263 package is used, the thermal resistance can be reduced by increasing the PC board copper area thermally connected to the package: Using

0.5 square inches of copper area, θ

Note 13: The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated output voltage to drop
approximately 40% from the nominal output voltage. This self protection feature lowers the average power dissipation of the IC by lowering the minimum duty cycle
from 5% down to approximately 2%.

Note 14: Refer to RETS LM1575J for current revision of military RETS/SMD.

= 30V for the 15V version. I

IN

Thermal Resistance T Package, Junction to Ambient (Note 9) 65

T Package, Junction to Ambient (Note 10) 45 ˚C/W

T Package, Junction to Case 2

N Package, Junction to Ambient (Note 11) 85

M Package, Junction to Ambient (Note 11) 100

S Package, Junction to Ambient (Note 12) 37

ON /OFF Pin Logic V

Input Level V

OUT

OUT

ON /OFF Pin Input ON /OFF Pin = 5V (OFF) 12 µA

Current 30 30 µA(Max)

ON /OFF Pin = 0V (ON) 0µA

= 40V (60V for the high voltage version).

IN

is 50˚C/W; with 1 square inch of copper area, θJAis 37˚C/W; and with 1.6 or more square inches of copper area, θJAis 32˚C/W.

JA

(Continued)

= 12V for the 3.3V, 5V, and Adjustable version, VIN= 25V for the 12V version,

IN

= 200 mA.

LOAD

LM2575HV-XX

Limit Limit

(Note 2) (Note 3)

= 0V 1.4 2.2/2.4 2.2/2.4 V(Min)

= Nominal Output Voltage 1.2 1.0/0.8 1.0/0.8 V(Max)

10 10 µA(Max)

1

⁄2inch leads in a socket, or on a PC

1

⁄2inch leads soldered to a PC board

(Limits)

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Typical Performance Characteristics (Circuit of Figure 2)

Normalized Output Voltage Line Regulation

01147532 01147533

Dropout Voltage Current Limit

LM1575/LM2575/LM2575HV

Quiescent Current

01147534

01147535

Standby

Quiescent Current

01147536 01147537

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