LM2585SADJNOPB

Manufacturer Part NumberLM2585SADJNOPB
ManufacturerNATIONAL
LM2585SADJNOPB datasheet
 


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LM2585
SIMPLE SWITCHER
General Description
The LM2585 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, and ad-
justable.
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 regula-
tors. 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.
The power switch is a 3.0A NPN device that can stand-off
65V. Protecting the power switch are current and thermal lim-
iting 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, cur-
rent 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 volt-
ages and output load conditions, is guaranteed for the power
supply system.
Connection Diagrams
Bent, Staggered Leads
5-Lead TO-220 (T)
Top View
5-Lead TO-263 (S)
Top View
Order Number LM2585S-3.3, LM2585S-5.0,
LM2585S-12 or LM2585S-ADJ
SIMPLE SWITCHER
®
is a registered trademark of National Semiconductor Corporation
© 2007 National Semiconductor Corporation
®
3A Flyback Regulator
Features
Requires few external components
Family of standard inductors and transformers
NPN output switches 3.0A, can stand off 65V
Wide input voltage range: 4V to 40V
Current-mode operation for improved transient response,
line regulation, and current limit
100 kHz switching frequency
Internal soft-start function reduces in-rush current during
start-up
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
Flyback regulator
Multiple-output regulator
Simple boost regulator
Forward converter
1251514
Order Number LM2585T-3.3, LM2585T-5.0,
LM2585T-12 or LM2585T-ADJ
See NS Package Number T05D
1251516
12515
February 2007
Bent, Staggered Leads
5-Lead TO-220 (T)
Side View
1251515
5-Lead TO-263 (S)
Side View
1251517
See NS Package Number TS5B
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