Multi-topology DC/DC converters with internal switches rated 50V, 2A

April 14, 2014 // By Graham Prophet
LT8471 is a dual DC/DC converter that contains two internal 2A, 50V switches and an additional 500mA switch for step-down, step-up, and inverting conversions. Each 2A channel can be independently configured as a buck, boost, SEPIC, flyback, ZETA or inverting DC/DC converter.

This broad range of topologies and output configurations makes it suitable for a wide range of industrial and automotive applications. LT8471 operates from an input voltage range of 2.6V to 50V, for input sources ranging from a single-cell Li-Ion to automotive batteries.

The LT8471’s 50V internal switches can accommodate applications with inputs and outputs as high as 45V. The device is capable of generating both positive and negative outputs from a single converter, making it ideal for a wide array of biasing applications. A small integrated 500mA boost converter facilitates both buck and single inductor inverting applications at optimal efficiencies. The LT8471’s switching frequency is programmable and synchronisable from 100 kHz to 2 MHz, which keeps external components very small. The combination of a TSSOP package and tiny externals ensures a very compact footprint while minimising solution cost.

The LT8471’s high efficiency 50V switches deliver overall efficiencies up to 85% for buck and inverting applications. From a 6V to 32V input, the LT8471 delivers up to 1.5A at 5V and 650 mA at -5V. A power-good pin on each channel is offered for ease of use when event-based sequencing is required. The LT8471’s switching frequency can be programmed via a single resistor or synchronised to an external clock , minimising external component size and avoiding “noise critical” frequency bands. Anti-phase switching minimises input ripple. Undervoltage and overvoltage lockout (UVLO/OVLO) is user adjustable for optimal system performance. Other features include external synchronization capability, soft-start and frequency foldback.

The LT8471EFE comes in a 20-lead, thermally enhanced TSSOP package, priced at $3.75 (1000). An industrial temperature (-40°C to 125°C) version, the LT8471IFE, is priced at $4.13 (1000).

Linear Technology; www.linear.com/product/LT8471