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LM2576, LM2576HV

www.ti.com

SNVS107C –JUNE 1999–REVISED APRIL 2013

LM2576/LM2576HV Series SIMPLE SWITCHER

3A Step-Down Voltage Regulator

Check for Samples: LM2576, LM2576HV

FEATURES

DESCRIPTION

The LM2576 series of regulators are monolithic

• 3.3V, 5V, 12V, 15V, and Adjustable Output

integrated circuits that provide all the active functions

Versions

for a step-down (buck) switching regulator, capable of

• Adjustable Version Output Voltage

driving 3A load with excellent line and load regulation.

Range,1.23V to 37V (57V for HV Version) ±4%

These devices are available in fixed output voltages

Max Over Line and Load Conditions

of 3.3V, 5V, 12V, 15V, and an adjustable output

version.

• Specified 3A Output Current

• Wide Input Voltage Range, 40V Up to 60V for

Requiring a minimum number of external

HV Version components, these regulators are simple to use and

include internal frequency compensation and a fixed-

• Requires Only 4 External Components

frequency oscillator.

• 52 kHz Fixed Frequency Internal Oscillator

The LM2576 series offers a high-efficiency

• TTL Shutdown Capability, Low Power Standby

replacement for popular three-terminal linear

Mode

regulators. It substantially reduces the size of the

• High Efficiency

heat sink, and in some cases no heat sink is

required.

• Uses Readily Available Standard Inductors

• Thermal Shutdown and Current Limit

A standard series of inductors optimized for use with

Protection

the LM2576 are available from several different

manufacturers. This feature greatly simplifies the

• P+ Product Enhancement Tested

design of switch-mode power supplies.

APPLICATIONS

Other features include a specified ±4% tolerance on

output voltage within specified input voltages and

• Simple High-Efficiency Step-Down (Buck)

output load conditions, and ±10% on the oscillator

Regulator

frequency. External shutdown is included, featuring

• Efficient Pre-Regulator for Linear Regulators

50 μA (typical) standby current. The output switch

includes cycle-by-cycle current limiting, as well as

• On-Card Switching Regulators

thermal shutdown for full protection under fault

• Positive to Negative Converter (Buck-Boost)

conditions.

TYPICAL APPLICATION

(Fixed Output Voltage Versions)

Figure 1.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2SIMPLE SWITCHER is a registered trademark of Texas Instruments.

3All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (37 pages)

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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 LM2576/LM2576HV Series SIMPLE SWITCHER® 3A Step-Down Voltage Regulator Check for Samples: LM2576, LM2576HV FEATURES DESCRIPTION • The LM2576 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving 3A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com Block Diagram 3.3V R2 = 1.7k 5V, R2 = 3.1k 12V, R2 = 8.84k 15V, R2 = 11.3k For ADJ.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. ABSOLUTE MAXIMUM RATINGS (1) (2) Maximum Supply Voltage LM2576 45V LM2576HV 63V −0.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com ELECTRICAL CHARACTERISTICS LM2576-5.0, LM2576HV-5.0 Specifications with standard type face are for TJ = 25°C, and those with Figure 21 and Figure 22 boldface type apply over full Operating Temperature Range. Symbol Parameter LM2576-5.0 LM2576HV-5.0 Conditions Typ Limit (1) Units (Limits) SYSTEM PARAMETERS Figure 21 and Figure 22 (2) VOUT Output Voltage VOUT VOUT η (1) (2) VIN = 12V, ILOAD = 0.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 ELECTRICAL CHARACTERISTICS LM2576-15, LM2576HV-15 Specifications with standard type face are for TJ = 25°C, and those with boldface type apply over full Operating Temperature Range. Symbol Parameter LM2576-15 LM2576HV-15 Conditions Typ Limit Units (Limits) (1) SYSTEM PARAMETERS Test Circuit Figure 21 and Figure 22 (2) VOUT VOUT VOUT η (1) (2) Output Voltage VIN = 25V, ILOAD = 0.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com ELECTRICAL CHARACTERISTICS ALL OUTPUT VOLTAGE VERSIONS Specifications with standard type face are for TJ = 25°C, and those with boldface type apply over full Operating Temperature Range. Unless otherwise specified, VIN = 12V for the 3.3V, 5V, and Adjustable version, VIN = 25V for the 12V version, and VIN = 30V for the 15V version. ILOAD = 500 mA.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 TYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 21 and Figure 22) Normalized Output Voltage Line Regulation Figure 2. Figure 3. Dropout Voltage Current Limit Figure 4. Figure 5. Quiescent Current Standby Quiescent Current Figure 6. Figure 7.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com TYPICAL PERFORMANCE CHARACTERISTICS (continued) (Circuit of Figure 21 and Figure 22) 8 Oscillator Frequency Switch Saturation Voltage Figure 8. Figure 9. Efficiency Minimum Operating Voltage Figure 10. Figure 11. Quiescent Current vs Duty Cycle Feedback Voltage vs Duty Cycle Figure 12. Figure 13.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 TYPICAL PERFORMANCE CHARACTERISTICS (continued) (Circuit of Figure 21 and Figure 22) Minimum Operating Voltage Quiescent Current vs Duty Cycle Figure 14. Figure 15. Feedback Voltage vs Duty Cycle Feedback Pin Current Figure 16. Figure 17.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com TYPICAL PERFORMANCE CHARACTERISTICS (continued) (Circuit of Figure 21 and Figure 22) Maximum Power Dissipation (DDPAK/TO-263) Switching Waveforms If the DDPAK/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, θJA is 50°C/W, with 1 square inch of copper area, θJA is 37°C/W, and with 1.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 TEST CIRCUIT AND LAYOUT GUIDELINES As in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance generate voltage transients which can cause problems. For minimal inductance and ground loops, the length of the leads indicated by heavy lines should be kept as short as possible. Single-point grounding (as indicated) or ground plane construction should be used for best results.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com LM2576 Series Buck Regulator Design Procedure PROCEDURE (Fixed Output Voltage Versions) EXAMPLE (Fixed Output Voltage Versions) Given: VOUT = Regulated Output Voltage (3.3V, 5V, 12V, or 15V) VIN(Max) = Maximum Input Voltage ILOAD(Max) = Maximum Load Current Given: VOUT = 5V VIN(Max) = 15V ILOAD(Max) = 3A 1. Inductor Selection (L1) A.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 INDUCTOR VALUE SELECTION GUIDES (For Continuous Mode Operation) Figure 23. LM2576(HV)-3.3 Figure 24. LM2576(HV)-5.0 Figure 25. LM2576(HV)-12 Figure 26.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com (For Continuous Mode Operation) Figure 27. LM2576(HV)-ADJ PROCEDURE (Adjustable Output Voltage Versions) Given: VOUT = Regulated Output Voltage VIN(Max) = Maximum Input Voltage ILOAD(Max) = Maximum Load Current F = Switching Frequency (Fixed at 52 kHz) EXAMPLE (Adjustable Output Voltage Versions) Given: VOUT = 10V VIN(Max) = 25V ILOAD(Max) = 3A F = 52 kHz 1. Programming Output Voltage (Selecting R1 and R2, as shown 1.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 (For Continuous Mode Operation) PROCEDURE (Adjustable Output Voltage Versions) EXAMPLE (Adjustable Output Voltage Versions) 2. Inductor Selection (L1) 2. Inductor Selection (L1) A. Calculate the inductor Volt • microsecond constant, E • T (V • μs), A. Calculate E • T (V • μs) from the following formula: B.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com Table 1. Diode Selection Guide Schottky VR 20V 3A Fast Recovery 4A–6A 1N5820 3A 4A–6A The following diodes are all rated to 100V 31DF1 HER302 The following diodes are all rated to 100V 50WF10 MUR410 HER602 1N5823 MBR320P SR302 30V 1N5821 50WQ03 MBR330 1N5824 31DQ03 SR303 40V 1N5822 MBR340 MBR340 50WQ04 31DQ04 1N5825 SR304 50V MBR350 50WQ05 31DQ05 SR305 60V MBR360 50WR06 DQ06 50SQ060 SR306 Table 2.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 APPLICATION HINTS INPUT CAPACITOR (CIN) To maintain stability, the regulator input pin must be bypassed with at least a 100 μF electrolytic capacitor. The capacitor's leads must be kept short, and located near the regulator. If the operating temperature range includes temperatures below −25°C, the input capacitor value may need to be larger.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com INDUCTOR RIPPLE CURRENT When the switcher is operating in the continuous mode, the inductor current waveform ranges from a triangular to a sawtooth type of waveform (depending on the input voltage). For a given input voltage and output voltage, the peak-to-peak amplitude of this inductor current waveform remains constant. As the load current rises or falls, the entire sawtooth current waveform also rises or falls.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 The voltage spikes are present because of the the fast switching action of the output switch, and the parasitic inductance of the output filter capacitor. To minimize these voltage spikes, special low inductance capacitors can be used, and their lead lengths must be kept short. Wiring inductance, stray capacitance, as well as the scope probe used to evaluate these transients, all contribute to the amplitude of these spikes.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com When using a heat sink, the junction temperature rise can be determined by the following: ΔTJ = (PD) (θJC + θinterface + θHeat sink) (6) The operating junction temperature will be: TJ = TA + ΔTJ (7) As in Equation 14, if the actual operating junction temperature is greater than the selected safe operating junction temperature, then a larger heat sink is required (one that has a lower thermal resistance).
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 Also, the maximum voltage appearing across the regulator is the absolute sum of the input and output voltage. For a −12V output, the maximum input voltage for the LM2576 is +28V, or +48V for the LM2576HV. The Switchers Made Simple (version 3.0) design software can be used to determine the feasibility of regulator designs using different topologies, different input-output parameters, different components, and so on.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com Complete circuit not shown (see Figure 28). Figure 31. Undervoltage Lockout for Buck-Boost Circuit DELAYED STARTUP The ON /OFF pin can be used to provide a delayed startup feature as shown in Figure 32. With an input voltage of 20V and for the part values shown, the circuit provides approximately 10 ms of delay time before the circuit begins switching. Increasing the RC time constant can provide longer delay times.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 DEFINITION OF TERMS BUCK REGULATOR A switching regulator topology in which a higher voltage is converted to a lower voltage. Also known as a step-down switching regulator. BUCK-BOOST REGULATOR A switching regulator topology in which a positive voltage is converted to a negative voltage without a transformer. DUTY CYCLE (D) Ratio of the output switch's on-time to the oscillator period.
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LM2576, LM2576HV SNVS107C – JUNE 1999 – REVISED APRIL 2013 www.ti.com Connection Diagrams (XX indicates output voltage option.) Top View Figure 35. Straight Leads 5-Lead TO-220 (T) Package LM2576T-XX or LM2576HVT-XX See Package Number KC0005A Top View Figure 36. DDPAK/TO-263 (S) Package 5-Lead Surface-Mount Package LM2576S-XX or LM2576HVS-XX See Package Number KTT0005B LM2576SX-XX or LM2576HVSX-XX See Package Number KTT0005B Top View Figure 37.
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LM2576, LM2576HV www.ti.com SNVS107C – JUNE 1999 – REVISED APRIL 2013 REVISION HISTORY Changes from Revision B (April 2013) to Revision C • Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.com 13-Nov-2013 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) LM2576HVS-12 NRND DDPAK/ TO-263 KTT 5 45 TBD Call TI Call TI -40 to 125 LM2576 HVS-12 P+ LM2576HVS-12/NOPB ACTIVE DDPAK/ TO-263 KTT 5 45 Pb-Free (RoHS Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2576 HVS-12 P+ LM2576HVS-3.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 13-Nov-2013 Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) LM2576S-5.0/NOPB ACTIVE DDPAK/ TO-263 KTT 5 45 Pb-Free (RoHS Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2576S -5.0 P+ LM2576S-ADJ/NOPB ACTIVE DDPAK/ TO-263 KTT 5 45 Pb-Free (RoHS Exempt) CU SN Level-3-245C-168 HR -40 to 125 LM2576S -ADJ P+ LM2576SX-3.
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PACKAGE OPTION ADDENDUM www.ti.com Orderable Device 13-Nov-2013 Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) LM2576T-5.0/NOPB ACTIVE TO-220 KC 5 45 Green (RoHS & no Sb/Br) CU SN Level-1-NA-UNLIM -40 to 125 LM2576T -5.
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PACKAGE OPTION ADDENDUM www.ti.com 13-Nov-2013 (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided.
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PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ LM2576HVSX-12 DDPAK/ TO-263 KTT 5 500 330.0 24.4 LM2576HVSX-12/NOPB DDPAK/ TO-263 KTT 5 500 330.0 LM2576HVSX-3.3/NOPB DDPAK/ TO-263 KTT 5 500 DDPAK/ TO-263 KTT 5 LM2576HVSX-5.0/NOPB DDPAK/ TO-263 KTT DDPAK/ TO-263 LM2576HVSX-ADJ/NOPB DDPAK/ TO-263 LM2576HVSX-5.
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PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM2576HVSX-12 DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-12/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-3.3/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-5.0 DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0 LM2576HVSX-5.0/NOPB DDPAK/TO-263 KTT 5 500 367.0 367.0 45.
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MECHANICAL DATA NDH0005D www.ti.
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MECHANICAL DATA KTT0005B TS5B (Rev D) BOTTOM SIDE OF PACKAGE www.ti.
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MECHANICAL DATA NEB0005B www.ti.
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