NSC LM2586T-3.3, LM2586SX-ADJ, LM2586SX-5.0, LM2586SX-3.3, LM2586SX-12 Datasheet

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LM2586 SIMPLE SWITCHER Shutdown

3A Flyback Regulator with

LM2586 SIMPLE SWITCHER 3A Flyback Regulator with Shutdown

May 1996

General Description

The LM2586 series of regulators are monolithic integrated circuits specifically designed for flyback, step-up (boost), and forward converter applications. The device is available in 4 different output voltage versions: 3.3V, 5.0V,12V,andadjustable.

Requiring a minimum number of external components,these regulators are cost effective, and simple to use. Included in the datasheet are typical circuits of boostandflybackregulators.Alsolistedare selector guides for diodes and capacitors and a family of standard inductors and flyback transformers designed to work with these switching regulators.

The power switch is a 3.0A NPN device that can stand-off 65V. Protecting the power switch are current and thermal limiting circuits, and an undervoltage lockout circuit. This IC contains an adjustable frequency oscillator that can be programmed up to 200kHz. The oscillator can also be synchronized with other devices, so that multiple devices can operate at the same switching frequency.

Other features includesoft start mode to reduce in-rush current during start up, and current mode control for improved rejection of input voltage and output load transients and cycle-by-cycle current limiting. The device also has a shutdown pin, so that it can be turned off externally. An output voltage tolerance of output load conditions, is guaranteed for the power supply system.

4%, within specified input voltages and

Flyback Regulator

Features

n Requires few external components n Family of standard inductors and transformers n NPN output switches 3.0A, can stand off 65V n Wide input voltage range: 4V to 40V n Adjustable switching frequency: 100 kHz to 200 kHz n External shutdown capability n Draws less than 60 µA when shut down n Frequency synchronization n Current-mode operation for improved transient

response, line regulation, and current limit

n Internal soft-start function reduces in-rush current during

start-up

n Output transistor protected by current limit, under

voltage lockout, and thermal shutdown

n System output voltage tolerance of

and load conditions

4%max over line

Typical Applications

n Flyback regulator n Forward converter n Multiple-output regulator n Simple boost regulator

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SIMPLE SWITCHER®and

Switchers Made Simple

are registered trademarks of National SemiconductorCorporation.

Ordering Information

Package Type NSC Package Order Number

Drawing

7-Lead TO-220 Bent, Staggered Leads TA07B LM2586T-3.3, LM2586T-5.0, LM2586T-12, LM2586T-ADJ 7-Lead TO-263 TS7B LM2586S-3.3, LM2586S-5.0, LM2586S-12, LM2586S-ADJ 7-Lead TO-263 Tape and Reel TS7B LM2586SX-3.3, LM2586SX-5.0, LM2586SX-12,

LM2586SX-ADJ

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Absolute Maximum Ratings (Note 1)

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

Input Voltage −0.4V ≤ V Switch Voltage −0.4V ≤ V Switch Current (Note 2) Internally Limited Compensation Pin Voltage −0.4V ≤ V Feedback Pin Voltage −0.4V ≤ V ON /OFF Pin Voltage −0.4V ≤ VSH≤ 6V Sync Pin Voltage −0.4V ≤ V Power Dissipation (Note 3) Internally Limited

COMP

≤ 2V

SYNC

≤ 45V ≤ 65V

≤ 2.4V

OUT

≤ 2V

Lead Temperature (Soldering, 10 sec.) 260˚C

Maximum Junction Temperature (Note 3) 150˚C

Minimum ESD Rating

(C=100 pF, R=1.5 kΩ)2kV

Operating Ratings

Supply Voltage 4V ≤ VIN≤ 40V Output Switch Voltage 0V ≤ V Output Switch Current I Junction Temp. Range −40˚C ≤ T

≤ 60V

≤ 3.0A

≤ +125˚C

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

Electrical Characteristics

Specifications with standard type face are for T Range. Unless otherwise specified, V

25˚C, and those in bold type face apply over full Operating Temperature

5V.

LM2586-3.3

Symbol Parameters Conditions Typical Min Max Units

SYSTEM PARAMETERS Test Circuit of

∆V ∆V ∆V ∆I

OUT

OUT IN OUT

LOAD

Output Voltage V

/ Line Regulation V

/ Load Regulation V

η Efficiency V UNIQUE DEVICE PARAMETERS (Note 5) V

REF

Output Reference Measured at Feedback Pin 3.3 3.242/3.234 3.358/3.366 V Voltage V

∆V

REF

Reference Voltage V Line Regulation

Error Amp I Transconductance V

VOL

Error Amp V Voltage Gain R

Figure 1

(Note 4)

4V to 12V 3.3 3.17/3.14 3.43/3.46 V

0.3 to 1.2A

LOAD

4V to 12V 20 50/100 mV

0.3A

LOAD

12V 20 50/100 mV

0.3A to 1.2A

LOAD

5V, I

COMP

4V to 40V 2.0 mV

COMP

COMP COMP COMP

0.3A 76

LOAD

1.0V

−30 µA to +30 µA 1.193 0.678 2.259 mmho

1.0V

0.5V to 1.6V 260 151/75 V/V

1.0 MΩ (Note 6)

LM2586-5.0

Symbol Parameters Conditions Typical Min Max Units

SYSTEM PARAMETERS Test Circuit of

∆V ∆V ∆V ∆I

OUT

OUT IN OUT

LOAD

Output Voltage V

/ Line Regulation V

/ Load Regulation V

η Efficiency V UNIQUE DEVICE PARAMETERS (Note 5) V

∆V

REF

Output Reference Voltage

Reference Voltage V

Figure 1

(Note 4)

4V to 12V 5.0 4.80/4.75 5.20/5.25 V

0.3A to 1.1A

LOAD

4V to 12V 20 50/100 mV

0.3A

LOAD

12V 20 50/100 mV

0.3A to 1.1A

LOAD

12V, I

Measured at Feedback Pin

COMP

4V to 40V 3.3 mV

1.0V

0.6A 80

LOAD

5.0 4.913/4.900 5.088/5.100 V

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LM2586-5.0 (Continued)

Symbol Parameters Conditions Typical Min Max Units

UNIQUE DEVICE PARAMETERS (Note 5)

Line Regulation

Error Amp I Transconductance V

VOL

Error Amp V Voltage Gain R

−30 µA to +30 µA 0.750 0.447 1.491 mmho

COMP

1.0V

COMP

0.5V to 1.6V 165 99/49 V/V

COMP

1.0 MΩ (Note 6)

COMP

LM2586-12

Symbol Parameters Conditions Typical Min Max Units

SYSTEM PARAMETERS Test Circuit of

∆V ∆V ∆V ∆I

OUT

OUT IN OUT

LOAD

Output Voltage V

/ Line Regulation V

/ Load Regulation V

η Efficiency V UNIQUE DEVICE PARAMETERS (Note 5) V

REF

Output Reference Measured at Feedback Pin 12.0 11.79/11.76 12.21/12.24 V Voltage V

∆V

REF

Reference Voltage V Line Regulation

Error Amp I Transconductance V

VOL

Error Amp V Voltage Gain R

Figure 2

(Note 4)

4V to 10V 12.0 11.52/11.40 12.48/12.60 V

0.2A to 0.8A

LOAD

4V to 10V 20 100/200 mV

0.2A

LOAD

10V 20 100/200 mV

0.2A to 0.8A

LOAD

10V, I

COMP

4V to 40V 7.8 mV

COMP

0.6A 93

LOAD

1.0V

−30 µA to +30 µA 0.328 0.186 0.621 mmho

1.0V

0.5V to 1.6V 70 41/21 V/V

1.0 MΩ (Note 6)

LM2586-ADJ

Symbol Parameters Conditions Typical Min Max Units

SYSTEM PARAMETERS Test Circuit of

∆V ∆V ∆V ∆I

OUT

LOAD

Output Voltage V

/ Line Regulation V

OUT IN

/ Load Regulation V

OUT

η Efficiency V UNIQUE DEVICE PARAMETERS (Note 5) V

REF

Output Reference Measured at Feedback Pin 1.230 1.208/1.205 1.252/1.255 V Voltage V

∆V

Reference Voltage V

REF

Line Regulation

Error Amp I Transconductance V

VOL

Error Amp Voltage Gain V

Error Amp V Input Bias Current

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Figure 2

(Note 4)

4V to 10V 12.0 11.52/11.40 12.48/12.60 V

0.2A to 0.8A

LOAD

4V to 10V 20 100/200 mV

0.2A

LOAD

10V 20 100/200 mV

0.2A to 0.8A

LOAD

10V, I

COMP

4V to 40V 1.5 mV

COMP

0.6A 93

LOAD

1.0V

−30 µA to +30 µA 3.200 1.800 6.000 mmho

1.0V

0.5V to 1.6V,

1.0 MΩ (Note 6)

670 400/200 V/V

1.0V 125 425/600 nA

LM2586-ADJ (Continued)

Symbol Parameters Conditions Typical Min Max Units

COMMON DEVICE PARAMETERS for all versions (Note 5)

S/D

EAO

V V I

SYNC

θ θ

EAO

MAX

SUS SAT

STH

SHTH

JC JA

Input Supply Current Switch Off (Note 8) 11 15.5/16.5 mA

Shutdown Input V

SWITCH

1.8A 50 100/115 mA

3V 16 100/300 µA

Supply Current Input Supply R

100Ω 3.30 3.05 3.75 V

LOAD

Undervoltage Lockout Oscillator Frequency Measured at Switch Pin

LOAD

100Ω,V

1.0V 100 85/75 115/125 kHz

COMP

Freq. Adj. Pin Open (Pin 1)

22 kΩ 200 kHz

SET

Short-Circuit Measured at Switch Pin Frequency R

LOAD

FEEDBACK

100Ω 25 kHz

1.15V Error Amplifier Upper Limit 2.8 2.6/2.4 V Output Swing (Note 7)

Lower Limit 0.25 0.40/0.55 V

(Note 8) Error Amp (Note 9) Output Current 165 110/70 260/320 µA (Source or Sink) Soft Start Current V

Maximum Duty Cycle R

FEEDBACK

COMP LOAD

0.92V 11.0 8.0/7.0 17.0/19.0 µA

1.0V

100Ω 98 93/90

(Note 7) Switch Leakage Switch Off 15 300/600 µA Current V

SWITCH

60V Switch Sustaining Voltage dV/dT=1.5V/ns 65 V Switch Saturation Voltage I

SWITCH

3.0A 0.45 0.65/0.9 V NPN Switch Current Limit 4.0 3.0 7.0 A Synchronization F Threshold Voltage V Synchronization V Pin Current V ON/OFF Pin (Pin 1) V

200 kHz 0.75 0.625/0.40 0.875/1.00 V

SYNC

COMP

5V 100 200 µA

COMP

1V, V

SYNC

STH

1V 1.6 1.0/0.8 2.2/2.4 V Threshold Voltage (Note 10) ON/OFF Pin (Pin 1) V Current V Thermal Resistance T Package, Junction to

1V 40 15/10 65/75 µA

COMP

SHTH

Ambient (Note 11) T Package, Junction to

Ambient (Note 12) T Package, Junction to Case 2 S Package, Junction to

Ambient (Note 13) S Package, Junction to

˚C/W

Ambient (Note 14) S Package, Junction to

Ambient (Note 15) S Package, Junction to Case 2

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LM2586-ADJ (Continued)

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.These ratings apply when the current is limited to less than 1.2 mA

for pins 1, 2, 3, and 6. Operating ratings indicateconditions for which the device isintended to be functional, but deviceparameter specifications may not be guaranteed under these conditions. For guaranteed specifications and test conditions, see the Electrical Characteristics.

Note 2: Note that switch current and output current are not identical in a step-up regulator. Output current cannot be internally limited when the LM2586 is used as a step-up regulator. To prevent damage to the switch, the output current must be externally limited to 3A. However, output current is internally limited when the LM2586 is used as a flyback regulator (see the Application Hints section for more information).

Note 3: The junction temperature of the device (T dissipation of the device (P

. For a safe thermal design, check that the maximum power dissipated by the device is less than: PD≤ [T

(MAX)

allowable power dissipation, derate the maximum junction temperature — this ensures a margin of safety in the thermal design. Note 4: External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM2586 is used as

Figures 1, 2

shown in Note 5: All room temperature limits are 100%production tested, and all limits at temperature extremes are guaranteed via correlation using standard Statistical Qual-

ity Control (SQC) methods.

Note 6: A 1.0 MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuringA Note 7: Tomeasure this parameter, the feedback voltage is set to a low value, depending on the output version of the device, to force the error amplifier output high

and the switch on. Note 8: Tomeasure this parameter, the feedback voltage is set to a high value, depending on the output version of the device, to force the error amplifier output low

and the switch off. Note 9: Tomeasure the worst-case error amplifier output current, the LM2586 is tested with the feedback voltageset to its low value (Note 7) and at its high value

(Note 8). Note 10: When testing the minimum value, do not sink current from this pin — isolate it with a diode. If current is drawn from this pin, the frequency adjust circuit will

begin operation (see Note 11: Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with

board with minimum copper area. Note 12: Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically,with

containing approximately 4 square inches of (1 oz.) copper area surrounding the leads. Note 13: Junction to ambient thermal resistance for the 7 lead TO-263 mounted horizontally against a PC board area of 0.136 square inches (the same size as the

TO-263 package) of 1 oz. (0.0014 in. thick) copper. Note 14: Junction to ambient thermal resistance for the 7 leadTO-263 mounted horizontally against a PC board areaof 0.4896 square inches (3.6 times the area

of the TO-263 package) of 1 oz. (0.0014 in. thick) copper. Note 15: Junction to ambient thermal resistance for the 7 lead TO-263 mounted horizontally against a PC board copper area of 1.0064 square inches (7.4 times the

area of the TO-263 package) of 1 oz. (0.0014 in. thick) copper. Additional copper area will reduce thermal resistance further. See the thermal model in

Made Simple

software.

). A thermal shutdown will occur if the temperature exceedsthe maximum junction temperature of the device: PDx θJA+T

, system performance will be as specified by the system parameters.

Figure 41

) is a function of the ambient temperature (TA), the junction-to-ambient thermal resistance (θJA), and the power

J(MAX)−TA(MAX)

]/θJA. When calculating the maximum

VOL

⁄2inch leads in a socket, or on a PC

⁄2inch leads soldered to a PC board

A(MAX)

Switchers

≥ T

Typical Performance Characteristics

Supply Current vs Temperature

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Reference Voltage vs Temperature

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∆Reference Voltage vs Supply Voltage

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Typical Performance Characteristics (Continued)

Supply Current vs Switch Current

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Switch Saturation Voltage vs Temperature

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Error Amp Transconductance vs Temperature

Current Limit vs Temperature

Switch Transconductance vs Temperature

Error Amp Voltage Gain vs Temperature

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Feedback Pin Bias Current vs Temperature

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Oscillator Frequency vs Temperature

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Short Circuit Frequency vs Temperature

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Typical Performance Characteristics (Continued)

Shutdown Supply Current vs Temperature

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Connection Diagrams

Bent, Staggered Leads

7-Lead TO-220 (T)

Top View

7-Lead TO-263 (S)

Top View

ON/OFF Pin Current vs Voltage

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Bent, Staggered Leads

7-Lead TO-220 (T)

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Order Number LM2586T3.3, LM2586T-5.0,

LM2586T-12 or LM2586T-ADJ

See NS Package Number TA07B

7-Lead TO-263 (S)

Oscillator Frequency vs Resistance

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Side View

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Side View

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Order number LM2586S-3.3, LM2586S-5.0,

LM2586S-12 or LM2586S-ADJ

Tape and Reel Order Number LM2586SX-3.3,

LM2586SX-5.0, LM2586SX-12 or LM2586SX-ADJ

See NS Package Number TS7B

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DS012516-20

Test Circuits

— 100 µF, 25V Aluminum Electrolytic

IN1

— 0.1 µF Ceramic

IN2

T— 22 µH, 1:1 Schott D— 1N5820

— 680 µF, 16V Aluminum Electrolytic

OUT

— 0.47 µF Ceramic

—2k

— 100 µF, 25V Aluminum Electrolytic

IN1

— 0.1 µF Ceramic

IN2

L— 15 µH, Renco D— 1N5820

— 680 µF, 16V Aluminum Electrolytic

OUT

— 0.47 µF Ceramic

—2k

For 12V Devices: R1=Short (0Ω) and 2=Open For ADJ Devices: R1=48.75k,

67141450

RL-5472-5

0.1%and 2=5.62k,±0.1

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FIGURE 1. LM2586-3.3 and LM2586-5.0

DS012516-22

FIGURE 2. LM2586-12 and LM2586-ADJ

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