LTC4419 Datasheet

• Selects Highest Priority Valid Supply from Two Inputs
• Wide 1.8V to 18V Operating Range
• Internal Dual 2Ω, 0.5A Switches
• Low 3.6µA Operating Current
• Low 320nA V2 Current When V1 Connected to OUT
• Blocks Reverse and Cross Conduction Currents
• Reverse Supply Protection to –15V
• V2 Freshness Seal/Ship Mode
• ±1.5% Accurate Adjustable Switchover Threshold
• Two Auxiliary ±2.3% Accurate Voltage Comparators
• Overcurrent and Thermal Protection
• Thermally Enhanced 10-Pin 3mm × 3mm DFN and 12-Lead Exposed Pad MSOP Packages

• Low Power Battery Backup
• Portable Equipment
• Point-of-Sale (POS) Equipment

The LTC4419 is a dual input monolithic PowerPath^™ prioritizer with low operating current, that provides backup switchover for keeping critical circuitry alive during brown out and power loss conditions. Unlike diode-OR products, little current is drawn from the inactive supply even if its voltage is greater than the active supply.

Internal 2Ω, current limited PMOS switches provide power path selection from a primary input (V1) or a backup input (V2) to the output. An adjustable voltage monitor set via an external resistive divider provides flexibility in setting the V1 to V2 switchover threshold. When primary input V1 drops, the ADJ monitor input causes OUT to be switched to V2. Fast non-overlap switchover circuitry prevents both reverse and cross conduction while minimizing output droop.

The LTC4419 has two auxiliary comparators with open-drain outputs that provide flexible voltage monitoring. The V2ON output indicates if V2 is powering OUT. Freshness seal mode prevents V2 battery discharge during storage or shipment.