Features

• 1.2MHz Switching Frequency
• Low V_CESAT Switches: 330mV at 1.3A
• High Output Voltage: Up to 40V
• Wide Input Range: 2.4V to 16V
• Inverting Capability
• 5V at 630mA from 3.3V Input
• 12V at 320mA from 5V Input
• –12V at 200mA from 5V Input
• Uses Tiny Surface Mount Components
• Low Shutdown Current: <1µA
• Low Profile (0.75mm) 10-Lead 3mm × 3mm DFN Package

Typical Application

Description

The LT3471 dual switching regulator combines two 42V, 1.3A switches with error amplifiers that can sense to ground providing boost and inverting capability. The low V_CESAT bipolar switches enable the device to deliver high current outputs in a small footprint. The LT3471 switches at 1.2MHz, allowing the use of tiny, low cost and low profile inductors and capacitors. High inrush current at start-up is eliminated using the programmable soft-start function, where an external RC sets the current ramp rate. A constant frequency current mode PWM architecture results in low, predictable output noise that is easy to filter.

The LT3471 switches are rated at 42V, making the device ideal for boost converters up to ±40V as well as SEPIC and flyback designs. Each channel can generate 5V at up to 630mA from a 3.3V supply, or 5V at 510mA from four alkaline cells in a SEPIC design. The device can be configured as two boosts, a boost and inverter or two inverters.

The LT3471 is available in a low profile (0.75mm) 10-lead 3mm × 3mm DFN package.