LTC3126

Features n Seamless, Automatic Transition Between Two Input Power Sources n Wide Input Voltage Range: 2.4V to 42V n Wide Output Voltage Range: 0.818V to VIN n Up to 2.5A Continuous Output Current n Pin-Selectable Priority and Ideal Diode-OR Modes n Burst Mode® Operation, IQ = 2µA n 95% Efficiency at 1A, VIN = 12V, VOUT = 5V n 1µA Current in Shutdown n Programmable Input UVLO Thresholds n Input Valid, Priority Channel and PGOOD Indicators n 200kHz to 2.2MHz Fixed Frequency PWM n Synchronizable to an External Clock n Current Mode Control with 60ns Minimum On-Time n Minimal External Components n Thermally Enhanced 28-Lead 4mm × 5mm QFN and 28-Lead TSSOP Packages Applications n Portable Industrial/Communications Test Equipment n Battery and Supercapacitor Backup Power n Automotive Power with Battery Backup n Uninterruptible Power Supplies LTC3126 42V, 2.5A Synchronous Step-Down Regulator with No-Loss Input PowerPath Description The LTC®3126 is a high efficiency synchronous buck converter with an internal no-loss PowerPath™ supporting seamless operation from two separate input power sources. Pin-selectable ideal diode-OR and priority input modes with user programmable undervoltage lockout thresholds provide full control over the transition between the input power sources. The fast, automatic switchover provided by the internal PowerPath eliminates the need for hold-up capacitors and minimizes disturbances on the output rail. An active input channel indicator and independent input...