• 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 input voltage range: 4V to 24V
• Wide output voltage range: 1.23V to 20V
• 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

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.

The MIC4574 is available in 3.3V, and 5V fixed output versions or a 1.23V to 20V adjustable output version. Both versions are capable of driving a 0.5A load with excellent line and load regulation.

The feedback voltage is guaranteed to±2% tolerance for adjustable versions, and the output voltage is guaranteed to ±3% for fixed versions, within specified voltages and load conditions. The oscillator frequency is guaranteed to ±10%.

In shutdown mode, the regulator draws less than 200µA standby current. The regulator performs cycle-by-cycle current limiting and thermal shutdown for protection under fault conditions.

This series of simple switch-mode regulators requires a minimum number of external components and can operate using a standard series of inductors. Frequency compensation is provided internally.

The MIC4574 is available in DIP (N) packages for the industrial temperature range.