General Description

The MIC4574 is a series of easy to use fixed and adjustable BiCMOS step-down (buck) switch-mode voltage regulators. The 200kHz MIC4574 duplicates the pinout and function of the 52kHz LM2574. The higher switching frequency may allow up to a 2:1 reduction in output filter inductor size.

Features

• Fixed 200kHz operation

• 3.3V, 5V, and adjustable output versions

• Voltage over specified line and load conditions:

Fixed version: ±3 max. output voltage

Adjustable version: ±2 max. feedback voltage

• Guaranteed 0.5A switch current

• Wide 4V to 24V input voltage range

• Wide 1.23V to 20V output voltage range

• Requires minimum external components

• < 200µA typical shutdown mode

• 75 efficiency (adjustable version > 75 typ.)

• Standard inductors and capacitors are 25 of typical LM2574 values

• Thermal shutdown

• Overcurrent protection

• 100 electrical thermal limit burn-in

Applications

• Simple high-efficiency step-down (buck) regulator

• Efficient preregulator for linear regulators

• On-card switching regulators

• Positive-to-negative converter (inverting buck-boost)

• Isolated flyback converter using minimum external components

• Negative boost converter