Features

• Power Path Management for Systems with Multiple DC Sources
• Switches and Isolates Sources from 3.3V to 10V
• All N-Channel Switching to Reduce Power Losses and System Cost
• Built-In Step-Up Regulator for N-Channel Gate Drive
• Capacitor Inrush and Short-Circuit Current Limited
• User-Programmable Timer Prevents Overdissipation During Current Limiting
• Undervoltage Lockout Prevents Operation with Low Inputs
• Small Footprint: 16-Pin Narrow SSOP

Typical Application

Description

The LTC1473L provides reliable and efficient switching between two DC power sources. This device drives two external sets of back-to-back N-channel MOSFET switches to route power to the input of a low voltage system. An internal boost regulator provides the voltage to fully enhance the logic-level N-channel MOSFET switches while an internal under voltage lock-out circuit keeps the system alive down to 2.8V. The LTC1473L senses current to limit inrush between the batteries and the system supply capacitor during switch-over transitions or during fault conditions. A user-programmable timer monitors the time the MOSFET switches are in current limit and latches them off when the programmed time is exceeded. A unique “2-diode” logic mode ensures system start-up regardless of which input receives power first.