NSC LM2597M-12, LM2597HVN-5.0, LM2597HVN-3.3, LM2597HVN-12, LM2597HVMX-ADJ Datasheet

LM2597/LM2597HV
SIMPLE SWITCHER

®

Power Converter 150 kHz 0.5A

Step-Down Voltage Regulator, with Features

General Description

The LM2597/LM2597HV series of regulators are monolithic
integrated circuits that provide all the active functions for a
step-down (buck) switching regulator, capable of driving a

0.5A load with excellent line and load regulation. These de­vices are available in fixed output voltages of 3.3V, 5V, 12V,
and an adjustable output version, and are packaged in an
8-lead DIP and an 8-lead surface mount package.

This series of switching regulators is similar to the LM2594
series, with additional supervisory and performance features
added.

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

†

, improved line and load specifications,
fixed-frequency oscillator, Shutdown /Soft-start, error flag
delay and error flag output.

The LM2597/LM2597HV series operates at a switching fre­quency of 150 kHz thus allowing smaller sized filter compo­nents than what would be needed with lower frequency
switching regulators. Because of its high efficiency, the cop­per traces on the printed circuit board are normally the only
heat sinking needed.

A standard series of inductors (both through hole and sur­face mount types) are available from several different manu­facturers optimized for use with the LM2597/LM2597HV se­ries. This feature greatly simplifies the design of
switch-mode power supplies.

Other features include a guaranteed

±

4%tolerance on out­put voltage under all conditions of input voltage and output
load conditions, and

±

15%on the oscillator frequency. Ex­ternal shutdown is included, featuring typically 85 µA
standby current. Self protection features include a two stage
current limit for the output switch and an over temperature
shutdown for complete protection under fault conditions.

The LM2597HV is for use in applications requiring and input
voltage up to 60V.

Features

n 3.3V, 5V, 12V, and adjustable output versions
n Adjustable version output voltage range, 1.2V to 37V

(57V for HV version)

±

4%max over line and load

conditions

n Guaranteed 0.5A output current
n Available in 8-pin surface mount and DIP-8 package
n Input voltage range up to 60V
n 150 kHz fixed frequency internal oscillator
n Shutdown /Soft-start
n Out of regulation error flag
n Error output delay
n Bias Supply Pin (V

BS

) for internal circuitry improves

efficiency at high input voltages

n Low power standby mode, I

Q

typically 85 µA

n High Efficiency
n Uses readily available standard inductors
n Thermal shutdown and current limit protection

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

Typical Application (Fixed Output Voltage Versions)

SIMPLE SWITCHER®and

Switchers Made Simple

®

are registered trademarks ofNational Semiconductor Corporation.

DS012440-1

†

Patent Number 5,382,918.

March 1998

LM2597/LM2597HV SIMPLE SWITCHER Power Converter 150 kHz 0.5A Step-Down Voltage

Regulator, with Features

© 1999 National Semiconductor Corporation DS012440 www.national.com

Absolute Maximum Ratings (Note 1)

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

Maximum Supply Voltage (V

IN

)

LM2597 45V

LM2597HV 60V

SD /SS Pin Input Voltage (Note 2)

6V
Delay Pin Voltage (Note 2) 1.5V
Flag Pin Voltage −0.3 ≤ V ≤45V
Bias Supply Voltage (V

BS

) −0.3 ≤ V ≤30V
Feedback Pin Voltage −0.3 ≤ V ≤+25V
Output Voltage to Ground

(Steady State) −1V
Power Dissipation Internally limited
Storage Temperature Range −65˚C to +150˚C

ESD Susceptibility

Human Body Model (Note 3) 2 kV

Lead Temperature

M8 Package

Vapor Phase (60 sec.) +215˚C
Infrared (15 sec.) +220˚C

N Package (Soldering, 10 sec.) +260˚C

Maximum Junction Temperature +150˚C

Operating Conditions

Temperature Range −40˚C ≤ TJ+125˚C
Supply Voltage

LM2597 4.5V to 40V

LM2597HV 4.5V to 60V

LM2597/LM2597HV-3.3
Electrical Characteristics

Specifications with standard type face are for T

J

=

25˚C, and those with boldface type apply over full Operating Tempera-

ture Range.V

INmax

=

40V for the LM2597 and 60V for the LM2597HV

Symbol Parameter Conditions LM2597/LM2597HV-3.3 Units

(Limits)

Typ Limit

(Note 4) (Note 5)

SYSTEM PARAMETERS (Note 6) Test Circuit

Figure 12

V

OUT

Output Voltage 4.75V ≤ VIN≤ V

INmax

, 0.1A ≤ I

LOAD

≤ 0.5A 3.3 V

3.168/3.135 V(min)

3.432/3.465 V(max)

η Efficiency V

IN

=

12V, I

LOAD

=

0.5A 80

%

LM2597/LM2597HV-5.0
Electrical Characteristics

Specifications with standard type face are for T

J

=

25˚C, and those with boldface type apply over full Operating Tempera-

ture Range.V

INmax

=

40V for the LM2597 and 60V for the LM2597HV

Symbol Parameter Conditions LM2597/LM2597HV-5.0 Units

(Limits)

Typ Limit

(Note 4) (Note 5)

SYSTEM PARAMETERS (Note 6) Test Circuit

Figure 12

V

OUT

Output Voltage 7V ≤ VIN≤ V

INmax

, 0.1A ≤ I

LOAD

≤ 0.5A 5 V

4.800/4.750 V(min)

5.200/5.250 V(max)

η Efficiency V

IN

=

12V, I

LOAD

=

0.5A 82

%

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LM2597/LM2597HV-12
Electrical Characteristics

Specifications with standard type face are for T

J

=

25˚C, and those with boldface type apply over full Operating Tempera-

ture Range.V

INmax

=

40V for the LM2597 and 60V for the LM2597HV

Symbol Parameter Conditions LM2597/LM2597HV-12 Units

(Limits)

Typ Limit

(Note 4) (Note 5)

SYSTEM PARAMETERS (Note 6) Test Circuit

Figure 12

V

OUT

Output Voltage 15V ≤ VIN≤ V

INmax

, 0.1A ≤ I

LOAD

≤ 0.5A 12 V

11.52/11.40 V(min)

12.48/12.60 V(max)

η Efficiency V

IN

=

25V, I

LOAD

=

0.5A 88

%

LM2597/LM2597HV-ADJ
Electrical Characteristics

Specifications with standard type face are for T

J

=

25˚C, and those with boldface type apply over full Operating Tempera-

ture Range.V

INmax

=

40V for the LM2597 and 60V for the LM2597HV

Symbol Parameter Conditions LM2597/LM2597HV-ADJ Units

(Limits)

Typ Limit

(Note 4) (Note 5)

SYSTEM PARAMETERS (Note 6) Test Circuit

Figure 12

V

FB

Feedback Voltage 4.5V ≤ VIN≤ V

INmax

, 0.1A ≤ I

LOAD

≤ 0.5A 1.230 V

V

OUT

programmed for 3V. Circuit of

Figure 12

. 1.193/1.180 V(min)

1.267/1.280 V(max)

η Efficiency V

IN

=

12V, V

OUT

=

3V, I

LOAD

=

0.5A 80

%

All Output Voltage Versions
Electrical Characteristics

Specifications with standard type face are for T

J

=

25˚C, and those with boldface type apply over full Operating Tempera-

ture Range. Unless otherwise specified, V

IN

=

12V for the 3.3V, 5V, and Adjustable version and V

IN

=

24V for the 12V ver-

sion. I

LOAD

=

100 mA.

Symbol Parameter Conditions LM2597/LM2597HV-XX Units

(Limits)

Typ Limit

(Note 4) (Note 5)

DEVICE PARAMETERS

I

b

Feedback Bias Current Adjustable Version Only, V

FB

=

1.235V 10 50/100 nA

f

O

Oscillator Frequency (Note 7) 150 kHz

127/110 kHz(min)
173/173 kHz(max)

V

SAT

Saturation Voltage I

OUT

=

0.5A (Notes 8 and 9) 0.9 V

1.1/1.2 V(max)

DC Max Duty Cycle (ON) (Note 9) 100

%

Min Duty Cycle (OFF) (Note 10) 0

I

CL

Current Limit Peak Current, (Notes 8 and 9) 0.8 A

0.65/0.58 A(min)

1.3/1.4 A(max)

I

L

Output Leakage Current (Notes 8, 10 and 11) Output=0V 50 µA(max)

Output=−1V 2 mA

15 mA(max)

I

Q

Operating Quiescent SD /SS Pin Open, VBSPin Open(Note 10) 5mA
Current 10 mA(max)

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All Output Voltage Versions
Electrical Characteristics

(Continued)

Specifications with standard type face are for T

J

=

25˚C, and those with boldface type apply over full Operating Tempera-

ture Range. Unless otherwise specified, V

IN

=

12V for the 3.3V, 5V, and Adjustable version and V

IN

=

24V for the 12V ver-

sion. I

LOAD

=

100 mA.

Symbol Parameter Conditions LM2597/LM2597HV-XX Units

(Limits)

Typ Limit

(Note 4) (Note 5)

DEVICE PARAMETERS

I

STBY

Standby Quiescent SD /SS pin=0V (Note 10)LM2597 85 µA
Current 200/250 µA(max)

LM2597HV 140 250/300 µA(max)

θ

JA

Thermal Resistance N Package, Junction to Ambient (Note 12) 95 ˚C/W

M Package, Junction to Ambient (Note 12) 150

SHUTDOWN/SOFT-START CONTROL Test Circuit of

Figure 12

V

SD

Shutdown Threshold 1.3 V
Voltage Low, (Shutdown Mode) 0.6 V(max)

High, (Soft-start Mode) 2 V(min)

V

SS

Soft-start Voltage V

OUT

=

20%of Nominal Output Voltage 2 V

V

OUT

=

100%of Nominal Output Voltage 3

I

SD

Shutdown Current V

SHUTDOWN

=

0.5V

5µA

10 µA(max)

I

SS

Soft-start Current V

Soft-start

=

2.5V 1.6 µA
5 µA(max)

FLAG/DELAY CONTROL Test Circuit of

Figure 12

Regulator Dropout Low (Flag ON) 96

%

Detector 92

%

(min)

Threshold Voltage 98

%

(max)

VF

SAT

Flag Output Saturation I

SINK

=

3 mA 0.3 V

Voltage V

DELAY

=

0.5V 0.7/1.0 V(max)

IF

L

Flag Output Leakage
Current

V

FLAG

=

40V 0.3 µA

Delay Pin Threshold 1.25 V
Voltage Low (Flag ON) 1.21 V(min)

High (Flag OFF) and V

OUT

Regulated 1.29 V(max)

Delay Pin Source V

DELAY

=

0.5V 3 µA
Current 6 µA(max)
Delay Pin Saturation Low (Flag ON) 55 mV

350/400 mV(max)

BIAS SUPPLY

I

BS

Bias Supply Pin Current V

BS

=

2V (Note 10) 120 µA

400 µA(max)

V

BS

=

4.4V (Note 10) 4 mA
10 mA(max)

I

Q

Operating Quiescent
Current

V

BS

=

4.4V , V

in

pin current(Note 10) 1 2 mA

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: Voltage internally clamped. If clamp voltage is exceeded, limit current to a maximum of 1 mA.
Note 3: The human body model is a 100 pF capacitor discharged through a 1.5k resistor into each pin.
Note 4: Typical numbers are at 25˚C and represent the most likely norm.
Note 5: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits are 100%produc-

tion tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used to calculate
Average Outgoing Quality Level (AOQL).

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All Output Voltage Versions
Electrical Characteristics

(Continued)

Note 6: External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the LM2597/
LM2597HV is used as shown in the

Figure 12

test circuit, system performance will be as shown in system parameters section of Electrical Characteristics.

Note 7: The switching frequency is reduced when the second stage current limit is activated. The amount of reduction is determined by the severity of current over­load.

Note 8: No diode, inductor or capacitor connected to output pin.
Note 9: Feedback pin removed from output and connected to 0V to force the output transistor switch ON.
Note 10: Feedback pin removed from output and connected to 12V for the 3.3V,5V,and theADJ. version, and 15V for the 12V version, to force the output transistor

switch OFF.
Note 11: V

IN

=

40V for the LM2597 and 60V for the LM2597HV.

Note 12: Junction to ambient thermal resistance with approximately 1 square inch of printed circuit board copper surrounding the leads. Additional copper area will
lower thermal resistance further. See application hints in this data sheet and the thermal model in Switchers Made Simple

™

software.

Typical Performance Characteristics

Normalized
Output Voltage

DS012440-2

Line Regulation

DS012440-3

Efficiency

DS012440-4

Switch Saturation
Voltage

DS012440-5

Switch Current Limit

DS012440-6

Dropout Voltage

DS012440-7

Quiescent Current

DS012440-8

Standby
Quiescent Current

DS012440-9

Minimum Operating
Supply Voltage

DS012440-10

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Typical Performance Characteristics (Continued)

Feedback Pin
Bias Current

DS012440-11

Flag Saturation
Voltage

DS012440-12

Switching Frequency

DS012440-13

Soft-start

DS012440-14

Shutdown /Soft-start
Current

DS012440-15

Delay Pin Current

DS012440-16

VINand VBSCurrent vs
V

BS

and Temperature

DS012440-17

Soft-start Response

DS012440-18

Shutdown /Soft-start
Threshold Voltage

DS012440-25

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Typical Performance Characteristics (Continued)

Connection Diagrams and Ordering Information

Continuous Mode Switching Waveforms
V

IN

=

20V, V

OUT

=

5V, I

LOAD

=

400 mA

L=100 µH, C

OUT

=

120 µF, C

OUT

ESR=140 mΩ

DS012440-19

A: Output Pin Voltage, 10V/div.
B: Inductor Current 0.2A/div.
C: Output Ripple Voltage, 20 mV/div.

Horizontal Time Base: 2 µs/div.

Discontinuous Mode Switching Waveforms
V

IN

=

20V, V

OUT

=

5V, I

LOAD

=

200 mA

L=33 µH, C

OUT

=

220 µF, C

OUT

ESR=60 mΩ

DS012440-20

A: Output Pin Voltage, 10V/div.
B: Inductor Current 0.2A/div.
C: Output Ripple Voltage, 20 mV/div.

Horizontal Time Base: 2 µs/div.

Load Transient Response for Continuous Mode
V

IN

=

20V, V

OUT

=

5V, I

LOAD

=

200 mA to 500 mA

L=100 µH, C

OUT

=

120 µF, C

OUT

ESR=140 mΩ

DS012440-21

A: Output Voltage, 50 mV/div. (AC)
B: 200 mA to 500 mA Load Pulse

Horizontal Time Base: 50 µs/div.

Load Transient Response for Discontinuous Mode
V

IN

=

20V, V

OUT

=

5V, I

LOAD

=

100 mA to 200 mA

L=33 µH, C

OUT

=

220 µF, C

OUT

ESR=60 mΩ

DS012440-22

A: Output Voltage, 50 mV/div. (AC)
B: 100 mA to 200 mA Load Pulse

Horizontal Time Base: 200 µs/div.

8–Lead DIP (N)

DS012440-23

Top View

Order Number LM2597N-3.3,

LM2597N-5.0, LM2597N-12 or

LM2597N-ADJ

LM2597HVN-3.3, LM2597HVN-5.0,

LM2597HVN-12 or LM2597HVN-ADJ

See NS Package Number N08E

8–Lead Surface Mount (M)

DS012440-24

Top View

Order Number LM2597M-3.3,

LM2597M-5.0, LM2597M-12 or

LM2597M-ADJ

LM2597HVM-3.3, LM2597HVM-5.0,

LM2597HVM-12 or LM2597HVM-ADJ

See NS Package Number M08A

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LM2597/LM2597HV Series Buck Regulator Design Procedure (Fixed
Output)

PROCEDURE (Fixed Output Voltage Version) EXAMPLE (Fixed Output Voltage Version)

Given:

V

OUT

=

Regulated Output Voltage (3.3V, 5V or 12V)

V

IN

(max)=Maximum DC Input Voltage

I

LOAD

(max)=Maximum Load Current

Given:

V

OUT

=

5V

V

IN

(max)=12V

I

LOAD

(max)=0.4A

1. Inductor Selection (L1)
A. Select the correct inductor value selection guide from

Fig-

ure 3

,

Figure 4

,or

Figure 5

. (Output voltages of 3.3V, 5V, or
12V respectively.) For all other voltages, see the design pro­cedure for the adjustable version.

B. From the inductor value selection guide, identify the induc­tance region intersected by the Maximum Input Voltage line
and the Maximum Load Current line. Each region is identified
by an inductance value and an inductor code (LXX).

C. Select an appropriate inductor from the four manufacturer’s
part numbers listed in

Figure 7

.

1. Inductor Selection (L1)
A. Use the inductor selection guide for the 5V version shown

in

Figure 4

.

B. From the inductor value selection guide shown in

Figure 4

,
the inductance region intersected by the 12V horizontal line
and the 0.4A vertical line is 100 µH, and the inductor code is
L20.

C. The inductance value required is 100 µH. From the table in

Figure 7

, go to the L20 line and choose an inductor part num­ber from any of the four manufacturers shown. (In most in­stance, both through hole and surface mount inductors are
available.)

2. Output Capacitor Selection (C

OUT

)

A. In the majority of applications, low ESR (Equivalent Series

Resistance) electrolytic capacitors between 82 µF and 220 µF
and low ESR solid tantalum capacitors between 15 µF and
100 µF provide the best results. This capacitor should be lo­cated close to the IC using short capacitor leads and short
copper traces. Do not use capacitors larger than 220 µF.

For additional information, see section on output capaci­tors in application information section.

B. To simplify the capacitor selection procedure, refer to the

quick design component selection table shown in

Figure 1

.
This table contains different input voltages, output voltages,
and load currents, and lists various inductors and output ca­pacitors that will provide the best design solutions.

C. The capacitor voltage rating for electrolytic capacitors
should be at least 1.5 times greater than the output voltage,
and often much higher voltage ratings are needed to satisfy
the low ESR requirements for low output ripple voltage.

D. For computer aided design software, see

Switchers Made

Simple

®

version 4.1 or later).

2. Output Capacitor Selection (C

OUT

)

A. See section on output capacitors in application infor­mation section.

B. From the quick design component selection table shown in

Figure 1

, locate the 5V output voltage section. In the load cur­rent column, choose the load current line that is closest to the
current needed in your application, for this example, use the

0.5A line. In the maximum input voltage column, select the
line that covers the input voltage needed in your application,
in this example, use the 15V line. Continuing on this line are
recommended inductors and capacitors that will provide the
best overall performance.

The capacitor list contains both through hole electrolytic and
surface mount tantalum capacitors from four different capaci­tor manufacturers. It is recommended that both the manufac­turers and the manufacturer’s series that are listed in the table
be used.

In this example aluminum electrolytic capacitors from several
different manufacturers are available with the range of ESR
numbers needed.

120 µF 25V Panasonic HFQ Series
120 µF 25V Nichicon PL Series

C. For a 5V output, a capacitor voltage rating at least 7.5V or
more is needed. But, in this example, even a low ESR, switch­ing grade, 120 µF 10V aluminum electrolytic capacitor would
exhibit approximately 400 mΩ of ESR (see the curve in

Figure

16

for the ESR vs voltage rating). This amount of ESR would
result in relatively high output ripple voltage. To reduce the
ripple to 1%of the output voltage, or less, a capacitor with a
higher voltage rating (lower ESR) should be selected. A 16V
or 25V capacitor will reduce the ripple voltage by approxi­mately half.

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LM2597/LM2597HV Series Buck Regulator Design Procedure (Fixed
Output)

(Continued)

PROCEDURE (Fixed Output Voltage Version) EXAMPLE (Fixed Output Voltage Version)

3. Catch Diode Selection (D1)
A. The catch diode current rating must be at least 1.3 times

greater than the maximum load current. Also, if the power
supply design must withstand a continuous output short, the
diode should have a current rating equal to the maximum cur­rent limit of the LM2597. The most stressful condition for this
diode is an overload or shorted output condition.

B. The reverse voltage rating of the diode should be at least

1.25 times the maximum input voltage.
C. This diode must be fast (short reverse recovery time) and

must be located close to the LM2597 using short leads and
short printed circuit traces. Because of their fast switching
speed and low forward voltage drop, Schottky diodes provide
the best performance and efficiency, and should be the first
choice, especially in low output voltage applications. Ultra-fast
recovery, or High-Efficiency rectifiers also provide good re­sults. Ultra-fast recovery diodes typically have reverse recov­ery times of 50 ns or less. Rectifiers such as the 1N4001 se­ries are much too slow and should not be used.

3. Catch Diode Selection (D1)
A. Refer to the table shown in

Figure 10

. In this example, a
1A, 20V, 1N5817 Schottky diode will provide the best perfor­mance, and will not be overstressed even for a shorted out­put.

4. Input Capacitor (C

IN

)

A low ESR aluminum or tantalum bypass capacitor is needed
between the input pin and ground to prevent large voltage
transients from appearing at the input. In addition, the RMS
current rating of the input capacitor should be selected to be
at least

1

⁄2the DC load current. The capacitor manufacturers
data sheet must be checked to assure that this current rating
is not exceeded. The curve shown in

Figure 15

shows typical
RMS current ratings for several different aluminum electrolytic
capacitor values.

This capacitor should be located close to the IC using short
leads and the voltage rating should be approximately 1.5
times the maximum input voltage.

If solid tantalum input capacitors are used, it is recommended
that they be surge current tested by the manufacturer.

Use caution when using ceramic capacitors for input bypass­ing, because it may cause severe ringing at the V

IN

pin.

For additional information, see section on input capaci­tors in Application Information section.

4. Input Capacitor (C

IN

)

The important parameters for the Input capacitor are the input
voltage rating and the RMS current rating. With a nominal in­put voltage of 12V, an aluminum electrolytic capacitor with a
voltage rating greater than 18V (1.5 x V

IN

) would be needed.

The next higher capacitor voltage rating is 25V.
The RMS current rating requirement for the input capacitor in

a buck regulator is approximately

1

⁄2the DC load current. In
this example, with a 400 mA load, a capacitor with a RMS cur­rent rating of at least 200 mA is needed. The curves shown in

Figure 15

can be used to select an appropriate input capaci­tor. From the curves, locate the 25V line and note which ca­pacitor values have RMS current ratings greater than 200 mA.
Either a 47 µF or 68 µF, 25V capacitor could be used.

For a through hole design, a 68 µF/25V electrolytic capacitor
(Panasonic HFQ series or Nichicon PL series or equivalent)
would be adequate. Other types or other manufacturers ca­pacitors can be used provided the RMS ripple current ratings
are adequate.

For surface mount designs, solid tantalum capacitors are rec­ommended. The TPS series available from AVX, and the
593D series from Sprague are both surge current tested.

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LM2597/LM2597HV Series Buck Regulator Design Procedure (Fixed
Output)

(Continued)

Conditions Inductor Output Capacitor

Through Hole Surface Mount

Output Load Max Input Inductance Inductor Panasonic Nichicon AVX TPS Sprague

Voltage Current Voltage (µH) (

#

) HFQ Series PL Series Series 595D Series

(V) (A) (V) (µF/V) (µF/V) (µF/V) (µF/V)

3.3 0.5 5 33 L14 220/16 220/16 100/16 100/6.3

7 47 L13 120/25 120/25 100/16 100/6.3
10 68 L21 120/25 120/25 100/16 100/6.3
40 100 L20 120/35 120/35 100/16 100/6.3

6 68 L4 120/25 120/25 100/16 100/6.3

0.2 10 150 L10 120/16 120/16 100/16 100/6.3
40 220 L9 120/16 120/16 100/16 100/6.3

5 0.5 8 47 L13 180/16 180/16 100/16 33/25

10 68 L21 180/16 180/16 100/16 33/25
15 100 L20 120/25 120/25 100/16 33/25
40 150 L19 120/25 120/25 100/16 33/25

9 150 L10 82/16 82/16 100/16 33/25

0.2 20 220 L9 120/16 120/16 100/16 33/25
40 330 L8 120/16 120/16 100/16 33/25

12 0.5 15 68 L21 82/25 82/25 100/16 15/25

18 150 L19 82/25 82/25 100/16 15/25
30 220 L27 82/25 82/25 100/16 15/25
40 330 L26 82/25 82/25 100/16 15/25
15 100 L11 82/25 82/25 100/16 15/25

0.2 20 220 L9 82/25 82/25 100/16 15/25
40 330 L17 82/25 82/25 100/16 15/25

FIGURE 1. LM2597/LM2597HV Fixed Voltage Quick Design Component Selection Table

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