Features

• Wide V_IN Range: 1.6V (2.5V Start-Up) to 40V
• Positive or Negative Output Voltage Programming with a Single Feedback Pin
• PGOOD Output Voltage Status Report
• Internal 6A/40V Power Switch
• Programmable Soft-Start
• Programmable Operating Frequency (100kHz to 1MHz) with One External Resistor
• Synchronizable to an External Clock
• Low Shutdown Current < 1μA
• INTV_CC Regulator Supplied from V_IN or DRIVE
• Programmable Input Undervoltage Lockout with Hysteresis
• Thermally Enhanced QFN (5mm × 6mm) and TSSOP Packages

Typical Application

Description

The LT®3959 is a wide input range, current mode, DC/DC controller which is capable of regulating either positive or negative output voltages from a single feedback pin. It can be configured as a boost, SEPIC or inverting converter.

It features an internal low side N-channel MOSFET rated for 6A at 40V and driven from an internal regulated supply provided from V_IN or DRIVE. The fixed frequency, current-mode architecture results in stable operation over a wide range of supply and output voltages. The operating frequency of LT3959 can be set over a 100kHz to 1MHz range with an external resistor, or can be synchronized to an external clock using the SYNC pin.

The LT3959 features soft-start and frequency foldback functions to limit inductor current during start-up and output short-circuit. A window comparator on the FBX pin reports via the PGOOD pin, providing output voltage status indication.