1 Introduction

This application report describes a dual output design using the LM5181 PSR fly-back DC/DC converter. A dual isolated output voltage rail of +/- 18 V at up to 65 mA is provided from an input voltage of 16 V to 32 V; see Table 1-1 . A bi-polar voltage rail is required for powering op-amps in many diverse signal chain applications. The design was implemented by modifying a standard dual output LM5180-Q1 EVM, found here: LM5180EVM_DUAL. Performance results, along with the schematic and BOM can be found within this report.

Although this design highlights the LM5181, other devices in this family can also be used, such as the LM5181-Q1, LM5180, and LM5180-Q1. Other common op-amp supply voltages are easily accommodated by making the changes shown in Table 1-2. For precision, low noise applications, the TPS7A39 dual LDO can be used as a post regulator.