Renesas' 40V multi-output isolated topology demonstration platforms use a single synchronous buck converter to realize multiple outputs (both inverting and non-inverting) as well as voltage step up/down function.

About 40V Multi-Output Isolated Topologies

Many applications require multiple voltage rails and are often limited by cost, footprint and height. In addition, ease of implementation and reduced complexity are often favored. As opposed to using multiple DC-DC converters to generate multiple outputs, which adds complexity to the circuit, additional voltage rails can be generated by using coupled inductors or transformers in place of the single filter inductor using isolated converter topologies.

Besides using coupled inductors or transformers to generate additional inverting or non-inverting voltage rails, the buck converter can be configured into an inverting buck boost converter. In this respect, an additional advantage of having a voltage step up function can be obtained in addition to having an inverting output. We will demonstrate how to use a single synchronous buck converter to realize multiple outputs (both inverting and non-inverting) as well as voltage step up/down function.

Galvanic isolation and multiple output applications are common in various power electronic applications, such as telecommunication applications, industrial programmable logic controllers (PLCs), industrial factory automation, isolated communication interfaces (i.e. RS-485, RS-232), bias supplies for gate drives, sensors, op-amps, motor drive applications and any application that requires positive and negative rails.

Applications

Industrial

  • Factory/Industrial Automation System 
  • PLC and I/O modules
  • Building Automation
  • Motor Drives
  • Smart Meters
  • Isolated Power Supplies for Medical Equipment
  • Isolated Fieldbus Interface
  • Smart Grid

Communications

  • IP phone
  • PoE IP Camera
  • DC-DC converter modules
Topologies

Isolated Buck Topology

Isolated Buck Topology

Inverting Buck-boost Topology

Inverting Buck-boost Topology

Isolated Buck-boost Topology

Isolated Buck-boost Topology