LM2585
www.ti.com
SNVS120F –APRIL 2000–REVISED APRIL 2013
®
LM2585 SIMPLE SWITCHER 3A Flyback Regulator
Check for Samples: LM2585
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FEATURES
DESCRIPTION
The LM2585 series of regulators are monolithic
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Requires Few External Components
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, and adjustable.
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Family of Standard Inductors and
Transformers
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NPN Output Switches 3.0A, Can Stand Off 65V
Wide Input Voltage Range: 4V to 40V
Requiring
a
minimum number of external
components, these regulators are cost effective, and
simple to use. Included in the datasheet are typical
circuits of boost and flyback regulators. Also listed
are selector guides for diodes and capacitors and a
family of standard inductors and flyback transformers
designed to work with these switching regulators.
Current-mode Operation for Improved
Transient Response, Line Regulation, and
Current Limit
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100 kHz Switching Frequency
Internal Soft-start Function Reduces In-rush
Current During Start-up
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 a 100 kHz fixed-
frequency internal oscillator that permits the use of
small magnetics. Other features include soft start
mode to reduce in-rush current during start up,
current mode control for improved rejection of input
voltage and output load transients and cycle-by-cycle
current limiting. An output voltage tolerance of ±4%,
within specified input voltages and output load
conditions, is specified for the power supply system.
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Output Transistor Protected by Current Limit,
Under Voltage Lockout, and Thermal
Shutdown
System Output Voltage Tolerance of ±4% Max
Over Line and Load Conditions
TYPICAL APPLICATIONS
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Flyback Regulator
Multiple-output Regulator
Simple Boost Regulator
Forward Converter
Connection Diagrams
Figure 3. Bent, Staggered Leads
5-Lead TO-220
Side View
See NDH005D Package
Figure 1. Bent, Staggered Leads
5-Lead TO-220
Top View
See NDH005D Package
Figure 4. 5-Lead DDPAK/TO-263
Side View
See KTT Package
Figure 2. 5-Lead DDPAK/TO-263
Top View
See KTT Package
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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.
Switchers Made Simple is a trademark of Texas Instruments.
SIMPLE SWITCHER is a registered trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
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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.
Copyright © 2000–2013, Texas Instruments Incorporated