The ADR1399E-EBZ and ADR1399H-EBZ allow the evaluation of the ADR1399KEZ, ultra-stable 7.05V Shunt Voltage Reference. The ADR1399E-EBZ is in 8-Pin LCC package and the ADR1399H-EBZ is in 4-lead TO-46 package.

The DUT on the ADR1399E-EBZ is on a paddle shaped “island” area of PCB for less stress from board flexure and also for thermal isolation. It is inside a captive acrylic enclosure to reduce air flow and further improve thermal isolation. Ground planes are removed under the DUT except for a hatch ground on the bottom side, again to prevent excessive thermal conduction away from the oven-ized reference. On L2 there is a small solid copper area under the reference voltage pins to help ensure an isothermal environment.

The DUT on the ADR1399H-EBZ is elevated on its leads in order to increase the thermal isolation from the 4-layer board ground planes.

Isolated power means that the Reference output is effectively floated, removing the likelihood of ground loops. The isolation is bridged only by a 1Meg resistor. Power may be supplied via the USB-C cable, or 5V may be applied to “VUSB”, or power may be back driven onto the LTM8048 regulator outputs at “VPRE” or V+”. The ultra-stable 7.05V is brought out to both banana jacks and to an edge mounted SMA connector.