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
* < 200A 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-inApplication* 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 converterPinout
SpecificationsSupply Voltage (VIN) Note 1 .......................................+40V
Shutdown (VSHDN) ....................................... 0.3V to +36V
Output Switch (VSW) steady state.................................1V
Junction Temperature (TJ) ......................................+150°C
Storage Temperature...............................65°C to +150°CDescriptionThe 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 of MIC4574 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.
MIC4574 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.
MIC4574 Data Sheet
