LM1577 NSC | Alldatasheet
Document overview
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Technical content
Features
n Requires few external components n NPN output switches 3.0A, can stand off 65V n Wide input voltage range: 3.5V to 40V n Current-mode operation for improved transient response, line regulation, and current limit n 52 kHz internal oscillator n Soft-start function reduces in-rush current during start-up n Output switch protected by current limit, under-voltage lockout, and thermal shutdown Typical Applications n Simple boost regulator n Flyback and forward regulators n Multiple-output regulator Typical Application
Ordering Information
−40˚C ≤ TA ≤ +125˚C 24-Pin Surface Mount LM2577M-12 LM2577M-15 LM2577M-ADJ M24B SO 16-Pin Molded DIP LM2577N-12 LM2577N-15 LM2577N-ADJ N16A N 5-Lead Surface Mount LM2577S-12 LM2577S-15 LM2577S-ADJ TS5B TO-263 5-Straight Leads LM2577T-12 LM2577T-15 LM2577T-ADJ T05A TO-220 5-Bent Staggered LM2577T-12 LM2577T-15 LM2577T-ADJ T05D TO-220 Leads Flow LB03 Flow LB03 Flow LB03 −55˚C ≤ T A ≤ +150˚C 4-Pin TO-3 LM1577K-12/883 LM1577K-15/883 LM1577K- ADJ/883 K04A TO-3 SIMPLE SWITCHER ® is a registered trademark of National Semiconductor Corporation. DS011468-1 Note:Pin numbers shown are for TO-220 (T) package. June 1999 LM1577/LM2577 Series SIMPLE SWITCHER Step-Up Voltage Regulator © 1999 National Semiconductor Corporation DS011468 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. Supply Voltage 45V Output Switch Voltage 65V Output Switch Current (Note 2) 6.0A Power Dissipation Internally Limited Storage Temperature Range −65˚C to +150˚C Lead Temperature (Soldering, 10 sec.) 260˚C Maximum Junction Temperature 150˚C Minimum ESD Rating (C = 100 pF, R= 1.5 kΩ )2 k V Operating Ratings Supply Voltage 3.5V ≤ VIN ≤ 40V Output Switch Voltage 0V ≤ VSWITCH ≤ 60V Output Switch Current I SWITCH ≤ 3.0A Junction Temperature Range LM1577 −55˚C ≤ TJ ≤ +150˚C LM2577 −40˚C ≤ TJ ≤ +125˚C Specifications with standard type face are for TJ = 25˚C, and those inbold type faceapply over fullOperating Temperature Range . Unless otherwise specified, VIN = 5V, and ISWITCH = 0. LM1577-12 LM2577-12 Units Symbol Parameter Conditions Typical Limit Limit (Limits) (Notes 3, 4) (Note 5) SYSTEM PARAMETERS Circuit ofFigure 1(Note 6) VOUT Output Voltage V IN = 5V to 10V 12.0 V ILOAD = 100 mA to 800 mA 11.60/ 11.40 11.60/11.40 V(min) (Note 3) 12.40/ 12.60 12.40/12.60 V(max) Line Regulation V IN = 3.5V to 10V 20 mV ILOAD = 300 mA 50/ 100 50/100 mV(max) Load Regulation V IN = 5V 20 mV ILOAD = 100 mA to 800 mA 50/ 100 50/100 mV(max) η Efficiency V IN = 5V, ILOAD = 800 mA 80 % DEVICE PARAMETERS IS Input Supply Current VFEEDBACK = 14V (Switch Off) 7.5 mA ISWITCH = 2.0A 25 mA VCOMP = 2.0V (Max Duty Cycle) 50/ 85 50/85 mA(max) VUV Input Supply I SWITCH = 100 mA 2.90 V Undervoltage Lockout 2.70/ 2.65 2.70/2.65 V(min) fO Oscillator Frequency Measured at Switch Pin 52 kHz ISWITCH = 100 mA 48/ 42 48/42 kHz(min) 56/62 56/62 kHz(max) VREF Output Reference Measured at Feedback Pin V Voltage V Output Reference V IN = 3.5V to 40V 7m V Voltage Line Regulator R FB Feedback Pin Input 9.7 k Ω Resistance G M Error Amp I COMP = −30 µA to +30 µA 370 µmho Transconductance V COMP = 1.0V 225/ 145 225/145 µmho(min) 515/615 515/615 µmho(max) AVOL Error Amp V COMP = 1.1V to 1.9V 80 V/V Voltage Gain R COMP = 1.0 MΩ 50/25 50/25 V/V(min) (Note 7) www.national.com 2
Specifications with standard type face are for TJ = 25˚C, and those inbold type faceapply over fullOperating Temperature Range . Unless otherwise specified, VIN = 5V, and ISWITCH = 0. LM1577-12 LM2577-12 Units Symbol Parameter Conditions Typical Limit Limit (Limits) (Notes 3, 4) (Note 5) DEVICE PARAMETERS Error Amplifier Upper Limit 2.4 V Output Swing V Lower Limit 0.3 V V Error Amplifier V FEEDBACK = 10.0V to 15.0V ±200 µA Output Current V COMP = 1.0V ±130/±90 ±130/±90 µA(min) ISS Soft Start Current V FEEDBACK = 10.0V 5.0 µA VCOMP = 0V 2.5/ 1.5 2.5/1.5 µA(min) D Maximum Duty Cycle V COMP = 1.5V 95 % ISWITCH = 100 mA 93/ 90 93/90 % (min) Switch Transconductance
12.5 A/V
IL Switch Leakage V SWITCH = 65V 10 µA Current V FEEDBACK = 15V (Switch Off) 300/ 600 300/600 µA(max) VSAT Switch Saturation I SWITCH = 2.0A 0.5 V NPN Switch 4.5 A Current Limit 3.7/ 3.0 3.7/3.0 A(min) Specifications with standard type face are for TJ = 25˚C, and those inbold type faceapply over fullOperating Temperature Range . Unless otherwise specified, VIN = 5V, and ISWITCH = 0. LM1577-15 LM2577-15 Units Symbol Parameter Conditions Typical Limit Limit (Limits) (Notes 3, 4) (Note 5) SYSTEM PARAMETERS Circuit ofFigure 2(Note 6) VOUT Output Voltage V IN = 5V to 12V 15.0 V ILOAD = 100 mA to 600 mA 14.50/ 14.25 14.50/14.25 V(min) (Note 3) 15.50/ 15.75 15.50/15.75 V(max) Line Regulation V IN = 3.5V to 12V 20 50/100 50/100 mV ILOAD = 300 mA mV(max) Load Regulation V IN = 5V 20 50/100 50/100 mV ILOAD = 100 mA to 600 mA mV(max) η Efficiency V IN = 5V, ILOAD = 600 mA 80 % DEVICE PARAMETERS IS Input Supply Current V FEEDBACK = 18.0V 7.5 mA (Switch Off) 10.0/ 14.0 10.0/14.0 mA(max) ISWITCH = 2.0A 25 mA VCOMP = 2.0V 50/ 85 50/85 mA(max) (Max Duty Cycle) VUV Input Supply I SWITCH = 100 mA 2.90 V www.national.com3
Specifications with standard type face are for TJ = 25˚C, and those inbold type faceapply over fullOperating Temperature Range . Unless otherwise specified, VIN = 5V, and ISWITCH = 0. LM1577-15 LM2577-15 Units Symbol Parameter Conditions Typical Limit Limit (Limits) (Notes 3, 4) (Note 5) DEVICE PARAMETERS Undervoltage 2.70/ 2.65 2.70/2.65 V(min) Lockout 3.10/ 3.15 3.10/3.15 V(max) fO Oscillator Frequency Measured at Switch Pin 52 kHz ISWITCH = 100 mA 48/ 42 48/42 kHz(min) 56/62 56/62 kHz(max) VREF Output Reference Measured at Feedback Pin V Voltage V Output Reference V IN = 3.5V to 40V 10 mV Voltage Line Regulation R FB Feedback Pin Input 12.2 k Ω Voltage Line Regulator G M Error Amp I COMP = −30 µA to +30 µA 300 µmho Transconductance V COMP = 1.0V 170/ 110 170/110 µmho(min) 420/500 420/500 µmho(max) AVOL Error Amp V COMP = 1.1V to 1.9V 65 V/V Voltage Gain R COMP = 1.0 MΩ 40/20 40/20 V/V(min) (Note 7) Error Amplifier Upper Limit 2.4 V Output Swing V Lower Limit 0.3 V V Error Amp V FEEDBACK = 12.0V to 18.0V ±200 µA Output Current V COMP = 1.0V ±130/±90 ±130/±90 µA(min) ISS Soft Start Current V FEEDBACK = 12.0V 5.0 µA VCOMP = 0V 2.5/ 1.5 2.5/1.5 µA(min) D Maximum Duty V COMP = 1.5V 95 % Cycle I SWITCH = 100 mA 93/ 90 93/90 % (min) Switch Transconductance IL Switch Leakage V SWITCH = 65V 10 µA Current V FEEDBACK = 18.0V 300/ 600 300/600 µA(max) (Switch Off) VSAT Switch Saturation I SWITCH = 2.0A 0.5 V (Max Duty Cycle) NPN Switch V COMP = 2.0V 4.3 A Current Limit 3.7/ 3.0 3.7/3.0 A(min) www.national.com 4
Specifications with standard type face are for TJ = 25˚C, and those inbold type faceapply over fullOperating Temperature Range . Unless otherwise specified, VIN = 5V, VFEEDBACK = VREF , and ISWITCH = 0. LM1577-ADJ LM2577-ADJ Units Symbol Parameter Conditions Typical Limit Limit (Limits) (Notes 3, 4) (Note 5) SYSTEM PARAMETERS Circuit ofFigure 3(Note 6) VOUT Output Voltage V IN = 5V to 10V 12.0 V ILOAD = 100 mA to 800 mA 11.60/ 11.40 11.60/11.40 V(min) (Note 3) 12.40/ 12.60 12.40/12.60 V(max) ΔVOUT / Line Regulation V IN = 3.5V to 10V 20 mV ΔVIN ILOAD = 300 mA 50/ 100 50/100 mV(max) ΔVOUT / Load Regulation V IN = 5V 20 mV ΔILOAD ILOAD = 100 mA to 800 mA 50/ 100 50/100 mV(max) η Efficiency V IN = 5V, ILOAD = 800 mA 80 % DEVICE PARAMETERS IS Input Supply Current VFEEDBACK = 1.5V (Switch Off) 7.5 mA ISWITCH = 2.0A 25 mA VCOMP = 2.0V (Max Duty Cycle) 50/ 85 50/85 mA(max) VUV Input Supply I SWITCH = 100 mA 2.90 V Undervoltage Lockout 2.70/ 2.65 2.70/2.65 V(min) fO Oscillator Frequency Measured at Switch Pin 52 kHz ISWITCH = 100 mA 48/ 42 48/42 kHz(min) 56/62 56/62 kHz(max) VREF Reference Measured at Feedback Pin V Voltage V ΔVREF / Reference Voltage V IN = 3.5V to 40V 0.5 mV ΔVIN Line Regulation IB Error Amp V COMP = 1.0V 100 nA Input Bias Current 300/ 800 300/800 nA(max) G M Error Amp I COMP = −30 µA to +30 µA 3700 µmho Transconductance V COMP = 1.0V 2400/ 1600 2400/1600 µmho(min) 4800/5800 4800/5800 µmho(max) AVOL Error Amp V COMP = 1.1V to 1.9V 800 V/V Voltage Gain R COMP = 1.0 MΩ (Note 7) 500/ 250 500/250 V/V(min) Error Amplifier Upper Limit 2.4 V Output Swing V Lower Limit 0.3 V V Error Amp V FEEDBACK = 1.0V to 1.5V ±200 µA Output Current V COMP = 1.0V ±130/±90 ±130/±90 µA(min) ISS Soft Start Current V FEEDBACK = 1.0V 5.0 µA VCOMP = 0V 2.5/ 1.5 2.5/1.5 µA(min) D Maximum Duty Cycle V COMP = 1.5V 95 % ISWITCH = 100 mA 93/ 90 93/90 % (min) ΔISWITCH / Switch 12.5 A/V ΔVCOMP Transconductance www.national.com5
Specifications with standard type face are for TJ = 25˚C, and those inbold type faceapply over fullOperating Temperature Range . Unless otherwise specified, VIN = 5V, VFEEDBACK = VREF , and ISWITCH = 0. LM1577-ADJ LM2577-ADJ Units Symbol Parameter Conditions Typical Limit Limit (Limits) (Notes 3, 4) (Note 5) DEVICE PARAMETERS I L Switch Leakage V SWITCH = 65V 10 µA Current V FEEDBACK = 1.5V (Switch Off) 300/ 600 300/600 µA(max) VSAT Switch Saturation I SWITCH = 2.0A 0.5 V NPN Switch V COMP = 2.0V 4.3 A Current Limit 3.7/ 3.0 3.7/3.0 A(min) THERMAL PARAMETERS (All Versions) θ JA Thermal Resistance K Package, Junction to Ambient 35 ˚C/W θJC K Package, Junction to Case 1.5 θJA T Package, Junction to Ambient 65 θJC T Package, Junction to Case 2 θJA N Package, Junction to 85 Ambient (Note 8) θ to Ambient (Note 8) θ Ambient (Note 9) Note 1:Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating ratings indicate conditions the device is intended to be functional, but device parameter specifications may not be guaranteed under these conditions. For guaranteed specifications and test conditions, see the Electrical Characteristics. Note 2:Due to timing considerations of the LM1577/LM2577 current limit circuit, output current cannot be internally limited when the LM1577/LM2577 is usedas a step-up regulator. To prevent damage to the switch, its current must be externally limited to 6.0A. However, output current is internally limited when the LM1577/ LM2577 is used as a flyback or forward converter regulator in accordance to the Application Hints. Note 3:All limits guaranteed at room temperature (standard type face) and at temperature extremes (boldface type). All limits are used to calculate Outgoing Quality Level, and are 100% production tested. Note 4:A military RETS electrical test specification is available on request. At the time of printing, the LM1577K-12/883, LM1577K-15/883, and LM1577K-ADJ/883 RETS specifications complied fully with the boldface limits in these columns. The LM1577K-12/883, LM1577K-15/883, and LM1577K-ADJ/883 may also beprocured to Standard Military Drawing specifications. Note 5:All limits guaranteed at room temperature (standard type face) and at temperature extremes (boldface type). 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. Note 6:External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM1577/LM2577 isused as shown in the Test Circuit, system performance will be as specified by the system parameters. Note 7:A 1.0 MΩ resistor is connected to the compensation pin (which is the error amplifier’s output) to ensure accuracy in measuring AVOL . In actual applications, this pin’s load resistance should be≥10 MΩ , resulting in AVOL that is typically twice the guaranteed minimum limit. Note 8: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 9: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,θJA is 50˚C/W; with 1 square inch of copper area,θJA is 37˚C/W; and with 1.6 or more square inches of copper area,θJA is 32˚C/W. www.national.com 6
Typical Performance Characteristics Reference Voltage vs Temperature DS011468-34 Reference Voltage vs Temperature DS011468-35 Reference Voltage vs Temperature DS011468-36 Δ Reference Voltage vs Supply Voltage DS011468-37 Δ Reference Voltage vs Supply Voltage DS011468-38 Δ Reference Voltage vs Supply Voltage DS011468-39 Error Amp Transconductance vs Temperature DS011468-40 Error Amp Transconductance vs Temperature DS011468-41 Error Amp Transconductance vs Temperature DS011468-42 www.national.com7
Typical Performance Characteristics(Continued) Error Amp Voltage Gain vs Temperature DS011468-43 Error Amp Voltage Gain vs Temperature DS011468-44 Error Amp Voltage Gain vs Temperature DS011468-45 Quiescent Current vs Temperature DS011468-46 Quiescent Current vs Switch Current DS011468-47 Current Limit vs Temperature DS011468-48 Current Limit Response Time vs Overdrive DS011468-49 Switch Saturation Voltage vs Switch Current DS011468-50 Switch Transconductance vs Temperature DS011468-51 www.national.com 8
Typical Performance Characteristics(Continued) Connection Diagrams Feedback Pin Bias Current vs Temperature DS011468-52 Oscillator Frequency vs Temperature DS011468-53 Maximum Power Dissipation (TO-263)(Note 9) DS011468-31 Straight Leads 5-Lead TO-220 (T) DS011468-4 Top View Order Number LM2577T-12, LM2577T-15, or LM2577T-ADJ See NS Package Number T05A Bent, Staggered Leads 5-Lead TO-220 (T) DS011468-5 Top View Order Number LM2577T-12 Flow LB03, LM2577T-15 Flow LB03, or LM2577T-ADJ Flow LB03 See NS Package Number T05D www.national.com9
Connection Diagrams (Continued) 16-Lead DIP (N) DS011468-6 *No internal Connection Top View Order Number LM2577N-12, LM2577N-15, or LM2577N-ADJ See NS Package Number N16A 24-Lead Surface Mount (M) DS011468-7 *No internal Connection Top View Order Number LM2577M-12, LM2577M-15, or LM2577M-ADJ See NS Package Number M24B TO-263 (S) 5-Lead Surface-Mount Package DS011468-32 Top View DS011468-33 Side View Order Number LM2577S-12, LM2577S-15, or LM2577S-ADJ See NS Package Number TS5B 4-Lead TO-3 (K) DS011468-8 Bottom View Order Number LM1577K-12/883, LM1577K-15/883, or LM1577K-ADJ/883 See NS Package Number K04A www.national.com 10
*Resistors are internal to LM1577/LM2577 for 12V and 15V versions. FIGURE 4. LM1577/LM2577 Block Diagram and Boost Regulator Application
- T and peak current, as this will saturate the core. Pulse:powdered iron, toroid core inductors; Benefits are low EMI and ability to withstand E•T and peak current above rated value better than ferrite cores. Renco: ferrite, bobbin-core inductors; Benefits are low cost and best ability to withstand E•T and peak current above rated value. Be aware that these inductors gener- ate more EMI than the other types, and this may inter- fere with signals sensitive to noise. DS011468-12 Note:These charts assume that the inductor ripple current inductor is approximately 20% to 30% of the average inductor current (when the regulator is under full load). Greater ripple current causes higher peak switch currents and greater output ripple voltage; lower ripple current is achieved with larger-value inductors. The factor of 20 to 30% is chosen as a convenient balance between the two extremes.
FIGURE 9. LM1577-ADJ/LM2577-ADJ Inductor Selection Graph
- Output Voltage Selection (R1 and R2)
or LM1577-15/LM2577-15 is being used.
- Input Capacitor Selection (CIN)
as short as possible) is normally sufficient. pacitors, an additional large electrolytic capacitor (e.g. part numbers and voltage ratings of 1A and 3A diodes. tion of this circuit are shown inFigure 16.
927 East Parkway,
9801 West Higgins Road,
FIGURE 11. Aluminum Electrolytic Capacitors FIGURE 12. Diode Selection Chart
FIGURE 27. Switching Waveforms of Flyback Regulator ofFigure 22, Each Output Loaded with 60Ω
Physical Dimensionsinches (millimeters) unless otherwise noted TO-3 Metal Can Package (K) Order Number LM1577K-12/883, LM1577K-15/883, or LM1577K-ADJ/883
0.300 Wide SO Package (M)
Order Number LM2577M-12, LM2577M-15 or LM2577M-ADJ www.national.com 24
Physical Dimensionsinches (millimeters) unless otherwise noted (Continued) Molded Dual-In-Line Package (N) Order Number LM2577N-12, LM2577N-15, or LM2577N-ADJ TO-220, Straight Leads (T) Order Number LM2577T-12, LM2577T-15, or LM2577T-ADJ www.national.com25
Physical Dimensionsinches (millimeters) unless otherwise noted (Continued) TO-220, Bent Staggered Leads (T) Order Number LM2577T-12 Flow LB03, LM2577T-15 Flow LB03, or LM2577T-ADJ Flow LB03 www.national.com 26
Physical Dimensionsinches (millimeters) unless otherwise noted (Continued) LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: sea.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 www.national.com 5-Lead TO-263 (S) Order Number LM2577S-12, LM2577S-15 or LM2577S-ADJ LM1577/LM2577 Series SIMPLE SWITCHER Step-Up Voltage Regulator National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.