24V/±15V/±12V/±5V Output Isolated DC/DC Board with LT3999

Equipment like industrial machinery and test instrument contains a lot of high-precision analog signal processing circuitry for sensing. Most of the time, those analog circuitries require positive and negative power lines. In addition, the power lines have to be isolated for reliability to prevent unexpected failure on sensor nodes to spread across the whole system.

Macnica Mpression team created this push-pull, low-noise, small DC/DC power reference board with LT3999 for analog circuitries used in industrial, medical, and tester applications that need operational isolation and variable input/output voltage up to 24V.

It allows for operational isolation for two lanes with a variable and a fixed output voltage, applicable for a wide range of isolation power use cases.

This reference board comes with Analog Devices isolated power controller LT3999 and a general-purpose transformer Wurth Elektronik 750344900. A transformer can often be an accessibility bottleneck, but our design uses a general-purpose transformer that lowers the level of concerns for the longtail nature of the target applications.
We also can add an enhanced isolation transformer for applications that need it.

Reference Board Features

  • Designed for evaluation of two types of isolated power supplies.
  • Power Circuit type 1: Input 24V, Output operationally isolated voltage selectable (±15V, ±12V, or ±5V) by jumper pins
  • Power circuit type 2: Input variable 5~24V, Output operationally isolated power at the same voltage as input (nominal tolerance ±10%)

LT3999 Features

  • Small solution footprint, monolithic DC/DC transformer driver to supply isolated power at high voltage and high switching frequency
  • Wide range of input operating voltage: 2.7V~36V
  • Low noise
  • Duty cycle programmable for adjusting output voltage using two 1A current limited power switches that switch out of phase.



Power Circuitry Type 1 (Operational Isolation, Positive-Negative Output)

Input Voltage 24V, 12V (jumper selectable)
Output Voltage ±15V, ±12V, ±5V (jumper selectable)
Output Current 100mA

Power Circuitry Type 2 (Operational Isolation Only)

Input Voltage 5V~24V
Output Voltage Same as Input (nominal)
Output Current Same as Input 




  BOM List


  Wurth Elektronik Transformer P/N 750344900  Data Sheet

  All documents (incl. CAD files)