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Part: LM2577
Category:
Power Management
-> Regulators
-> Switching Regulators
Description: LM2577 - Simple Switcher Step-up Voltage Regulator, Package: Soic Wide, Pin Nb=24
Company: National Semiconductor Corporation
Datasheet: Download LM2577 datasheet File size : 745 kB
Request For quote: Find where to buy LM2577
Datasheet text preview:
LM1577/LM2577 Series SIMPLE SWITCHER Step-Up Voltage Regulator
June 1999
LM1577/LM2577 Series SIMPLE SWITCHER ® Step-Up Voltage Regulator
General Description
The LM1577/LM2577 are monolithic integrated circuits that provide all of the power and control functions for step-up (boost), flyback, and forward converter switching regulators. The device is available in three different output voltage versions: 12V, 15V, and adjustable. Requiring a minimum number of external components, these regulators are cost effective, and simple to use. Listed in this data sheet are a family of standard inductors and flyback transformers designed to work with these switching regulators. Included on the chip is a 3.0A NPN switch and its associated protection circuitry, consisting of current and thermal limiting, and undervoltage lockout. Other features include a 52 kHz fixed-frequency oscillator that requires no external components, a soft start mode to reduce in-rush current during start-up, and current mode control for improved rejection of input voltage and output load transients.
Features
Requires few external components NPN output switches 3.0A, can stand off 65V Wide input voltage range: 3.5V to 40V 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 n n n n
Typical Applications
n Simple boost regulator n Flyback and forward regulators n Multiple-output regulator
Typical Application
DS011468-1
Note: Pin numbers shown are for TO-220 (T) package.
Ordering Information
Temperature Range -40°C TA +125°C Package Type 24-Pin Surface Mount 16-Pin Molded DIP 5-Lead Surface Mount 5-Straight Leads 5-Bent Staggered Leads -55°C TA +150°C 4-Pin TO-3 Output Voltage 12V LM2577M-12 LM2577N-12 LM2577S-12 LM2577T-12 LM2577T-12 Flow LB03 15V LM2577M-15 LM2577N-15 LM2577S-15 LM2577T-15 LM2577T-15 Flow LB03 ADJ LM2577M-ADJ LM2577N-ADJ LM2577S-ADJ LM2577T-ADJ LM2577T-ADJ Flow LB03 LM1577KADJ/883 K04A TO-3 NSC Package Package Drawing M24B N16A TS5B T05A T05D SO N TO-263 TO-220 TO-220
LM1577K-12/883 LM1577K-15/883
SIMPLE SWITCHER ® is a registered trademark of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation
DS011468
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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. Supply Voltage Output Switch Voltage Output Switch Current (Note 2) Power Dissipation Storage Temperature Range Lead Temperature (Soldering, 10 sec.) Maximum Junction Temperature 45V 65V 6.0A Internally Limited -65°C to +150°C 260°C 150°C
Minimum ESD Rating (C = 100 pF, R = 1.5 k)
2 kV
Operating Ratings
Supply Voltage Output Switch Voltage Output Switch Current Junction Temperature Range LM1577 LM2577 3.5V VIN 40V 0V VSWITCH 60V ISWITCH 3.0A -55°C TJ +150°C -40°C TJ +125°C
Electrical Characteristics -- LM1577-12, LM2577-12
Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V, and ISWITCH = 0. LM1577-12 Symbol Parameter Conditions Typical Limit (Notes 3, 4) SYSTEM PARAMETERS Circuit of Figure 1 (Note 6) VOUT Output Voltage VIN = 5V to 10V ILOAD = 100 mA to 800 mA Line Regulation (Note 3) VIN = 3.5V to 10V ILOAD = 300 mA Load Regulation IS VIN = 5V ILOAD = 100 mA to 800 mA Efficiency Input Supply Current VIN = 5V, ILOAD = 800 mA VFEEDBACK = 14V (Switch Off) ISWITCH = 2.0A VCOMP = 2.0V (Max Duty Cycle) ISWITCH = 100 mA 80 7.5 10.0/14.0 25 50/85 2.90 2.70/2.65 3.10/3.15 fO Oscillator Frequency Measured at Switch Pin ISWITCH = 100 mA Measured at Feedback Pin VIN = 3.5V to 40V VCOMP = 1.0V VIN = 3.5V to 40V 52 48/42 56/62 VREF Output Reference Voltage Output Reference Voltage Line Regulator RFB GM Feedback Pin Input Resistance Error Amp Transconductance AVOL Error Amp Voltage Gain ICOMP = -30 µA to +30 µA VCOMP = 1.0V VCOMP = 1.1V to 1.9V RCOMP = 1.0 M (Note 7) 370 225/145 515/615 80 50/25 50/25 225/145 515/615 µmho µmho(min) µmho(max) V/V V/V(min) 9.7 k 12 7 11.76/11.64 12.24/12.36 48/42 56/62 11.76/11.64 12.24/12.36 2.70/2.65 3.10/3.15 50/85 10.0/14.0 DEVICE PARAMETERS mA mA(max) mA mA(max) V V(min) V(max) kHz kHz(min) kHz(max) V V(min) V(max) mV 20 50/100 50/100 12.0 11.60/11.40 12.40/12.60 20 50/100 50/100 11.60/11.40 12.40/12.60 LM2577-12 Limit (Note 5) V V(min) V(max) mV mV(max) mV mV(max) % Units (Limits)
VUV
Input Supply Undervoltage Lockout
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2
Electrical Characteristics -- LM1577-12, LM2577-12
(Continued)
Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V, and ISWITCH = 0. LM1577-12 Symbol Parameter Conditions Typical Limit (Notes 3, 4) DEVICE PARAMETERS Error Amplifier Output Swing Upper Limit VFEEDBACK = 10.0V Lower Limit Error Amplifier Output Current ISS Soft Start Current VFEEDBACK = 15.0V VFEEDBACK = 10.0V to 15.0V VCOMP = 1.0V VFEEDBACK = 10.0V VCOMP = 0V VCOMP = 1.5V ISWITCH = 100 mA 2.4 2.2/2.0 0.3 0.40/0.55 0.40/0.55 2.2/2.0 V V(min) V V(max) µA µA(min) µA(max) µA 2.5/1.5 7.5/9.5 D Maximum Duty Cycle Switch Transconductance IL VSAT Switch Leakage Current Switch Saturation Voltage NPN Switch Current Limit VSWITCH = 65V VFEEDBACK = 15V (Switch Off) ISWITCH = 2.0A VCOMP = 2.0V (Max Duty Cycle) 4.5 3.7/3.0 5.3/6.0 3.7/3.0 5.3/6.0 95 93/90 12.5 93/90 2.5/1.5 7.5/9.5 µA(min) µA(max) % %(min) A/V LM2577-12 Limit (Note 5) Units (Limits)
± 200 ± 130/ ± 90 ± 300/ ± 400
5.0
± 130/ ± 90 ± 300/ ± 400
10 300/600 0.5 0.7/0.9 0.7/0.9 300/600
µA µA(max) V V(max) A A(min) A(max)
Electrical Characteristics -- LM1577-15, LM2577-15
Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V, and ISWITCH = 0. LM1577-15 Symbol Parameter Conditions Typical Limit (Notes 3, 4) SYSTEM PARAMETERS Circuit of Figure 2 (Note 6) VOUT Output Voltage VIN = 5V to 12V ILOAD = 100 mA to 600 mA Line Regulation (Note 3) VIN = 3.5V to 12V ILOAD = 300 mA Load Regulation IS VIN = 5V ILOAD = 100 mA to 600 mA Efficiency Input Supply Current VIN = 5V, ILOAD = 600 mA VFEEDBACK = 18.0V (Switch Off) ISWITCH = 2.0A VCOMP = 2.0V VUV Input Supply (Max Duty Cycle) ISWITCH = 100 mA
3
LM2577-15 Limit (Note 5)
Units (Limits)
15.0 14.50/14.25 15.50/15.75 20 50/100 20 50/100 80 7.5 10.0/14.0 25 50/85 2.90 50/85 10.0/14.0 50/100 50/100 14.50/14.25 15.50/15.75
V V(min) V(max) mV mV(max) mV mV(max) % mA mA(max) mA mA(max) V
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DEVICE PARAMETERS
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