Features

• Wide Input Range:
  – Operation from 7.5V to 30V
  – Overvoltage Lockout Protects Circuit Through 60V Transients
• Operates with LTC Bat-Track Li-Ion Battery Chargers to Maximize Efficiency
• No Reverse Discharge Path from V_OUT to V_IN
• Programmable Output Current Limit
• Integrated BOOST Diode
• Thermal Protection
• Small Application Size
• Thermally Enhanced 2mm × 3mm DFN Package

Typical Application

Description

The LT3653 is a monolithic current mode PWM step-down regulator with programmable output current limit. Typically, it is used with battery charger power path controllers to pre-regulate the output and optimize the battery charger efficiency. Output current limit provides accurate control over system power dissipation.

The wide operating input voltage range of 7.5V to 30V suits the LT3653 to a variety of input sources, including unregulated 12V wall adapters, 24V industrial supplies, Firewire and automotive power. Input overvoltage protection allows the LT3653 to handle 60V input transients.

The LT3653 control pin, V_C , is available for external battery tracking control, Bat-Track. The LT3653 will block output discharge during an open or shorted input.

The HVOK pin indicates that the internal bias supplies are present and no faults have occurred (i.e., overtemperature and input overvoltage and undervoltage). The LT3653 includes a 1.5MHz frequency oscillator, internal compensation, and an internal boost diode to minimize the number of external components. The LT3653 is available in an 8-lead (2mm × 3mm) package with exposed pads for low thermal resistance.