Description
The LT®3991 is an adjustable frequency monolithic buck switching regulator that accepts a wide input voltage range up to 55V.
Features
- n	 Ultralow Quiescent Current: 2.8µA IQ Regulating 12VIN to 3.3VOUT
n	 Fixed Output Voltages: 3.3V, 5V 	 2.1µA IQ Regulating 12VIN
n	 Low Ripple Burst Mode® Operation: Output Ripple < 15mVP-P
n	 Wide Input Voltage Range: 4.3V to 55V n	 1.2A Maximum Output Current n	 Adjustable Switching Frequency: 200kHz to 2MHz n	 Synchronizable Between 250kHz to 2MHz n	 Fast Transient Response n	 Accurate 1V Enable Pin Threshold n	 Low Shutdown Current: IQ = 700nA n	 Power Good Flag n	 Soft-Start CapabilityV n.