Features

• High Voltage: Operation Up to 60V
• High Current: N-Channel Drive Handles Up to 10,000pF Gate Capacitance
• Programmable Average Current Limiting
• 5V Reference Output with 10mA External Loading Capability
• Fixed Frequency Current Mode Operation
• Oscillator Synchronizable Up to 200kHz
• Undervoltage Lockout with Hysteresis
• Programmable Start Inhibit for Power Supply Sequencing and Protection
• User Adjustable Slope Compensation

Typical Application

Description

The LT1680 is a high power, current mode switching power supply controller optimized for boost topologies. The IC drives an N-channel MOSFET switch for DC/DC converter applications up to 60V input. A high current gate drive output handles up to 10,000pF gate capacitance, enabling the construction of high power DC/DC converters. Current sense common mode range up to 60V allows current sensing to be referenced to the input supply, eliminating the need for sense blanking circuits.

The LT1680 incorporates programmable average current limiting allowing accurate limiting of DC current in the magnetics, independent of ripple current. User adjustable slope compensation provides stable operation at duty cycles up to 90%.

The LT1680 operating frequency is programmable and can be synchronized up to 200kHz. Minimum off-time operation provides switch protection. The IC also incorporates a soft start feature that is gated by both shutdown and undervoltage lockout conditions.