深圳市中立信电子科技有限公司

FEATURES DESCRIPTION

234 The LM2585 series of regulators are monolithic • Requires Few External Components

integrated circuits specifically designed for flyback,

• Family of Standard Inductors and step-up (boost), and forward converter applications. Transformers The device is available in 4 different output voltage

• NPN Output Switches 3.0A, Can Stand Off 65V versions: 3.3V, 5.0V, 12V, and adjustable.

• Wide Input Voltage Range: 4V to 40V Requiring a minimum number of external

• Current-mode Operation for Improved components, these regulators are cost effective, and

Transient Response, Line Regulation, and simple to use. Included in the datasheet are typical

Current Limit circuits of boost and flyback regulators. Also listed

are selector guides for diodes and capacitors and a

• 100 kHz Switching Frequency family of standard inductors and flyback transformers

• Internal Soft-start Function Reduces In-rush designed to work with these switching regulators.

Current During Start-up The power switch is a 3.0A NPN device that can

• Output Transistor Protected by Current Limit, stand-off 65V. Protecting the power switch are current

Under Voltage Lockout, and Thermal and thermal limiting circuits, and an undervoltage

Shutdown lockout circuit. This IC contains a 100 kHz fixedfrequency

internal oscillator that permits the use of • System Output Voltage Tolerance of ±4% Max

Over Line small magnetics. Other features include soft start and Load Conditions

mode to reduce in-rush current during start up,

current mode control for improved rejection of input TYPICAL APPLICATIONS voltage and output load transients and cycle-by-cycle

• Flyback Regulator current limiting. An output voltage tolerance of ±4%,

• Multiple-output Regulator within specified input voltages and output load

conditions, is specified for the power supply system.

• Simple Boost Regulator

• Forward Converter