Features

• Wide Input Range: 2.5V to 60V
• Integrated Buck-Boost Supply for 7.5V MOSFET Gate Drive
• Programmable Constant-Current Operation with Current Monitor Output
• Low I_Q: 75μA, 12V_IN to 3.3V_OUT
• Selectable Low Output Ripple Burst Mode® Operation
• V_OUT Up to 60V
• Adjustable and Synchronizable: 50kHz to 1MHz
• Internal OVLO Protects for Input Transients Up to 80V
• Accurate Input Overvoltage and Undervoltage Threshold
• Programmable Soft-Start with Voltage Tracking
• Power Good and Output OVP
• 28-Lead TSSOP and 38-Lead 4mm × 6mm QFN Packages

Typical Application

Description

The LT®3840 is a high voltage synchronous step-down switching regulator controller capable of operating from a 2.5V to 60V supply.

The LT3840’s low quiescent current, when configured for user selectable Burst Mode operation, helps extend run time in battery-powered systems by increasing efficiency at light loads. The LT3840 uses a constant frequency, current mode architecture. High current applications are possible with large N-channel gate drivers capable of driving multiple low R_DS(ON) MOSFETs.

An integrated buck-boost switching regulator generates a 7.5V bias supply voltage for MOSFET gate drive and IC power allowing higher efficiency operation over the entire input voltage range and eliminating the need for an external bias voltage. An accurate current limit set point regulates the maximum output current. A current monitor reports the average output current.