SNVU699 October   2020

 

  1.   Trademarks
  2. 1Overview
    1. 1.1 REF70EVM Features
    2. 1.2 REF70EVM Schematic
    3. 1.3 REF70EVM Bill of Materials
    4. 1.4 REF70EVM Board
  3. 2Quick Setup Guide
    1. 2.1 Electrostatic Discharge Warning
    2. 2.2 Unpacking the EVM
    3. 2.3 Power Supply Setup and Functional Test
  4. 3EVM Theory and Operation
    1. 3.1 VREF Output's OUTF and OUFS
    2. 3.2 Output Capacitor
  5. 4Layout and Component Placement

3.1 VREF Output's OUTF and OUFS

The REF70 VREF is the output of the REF70 when the OUTF and OUTS are shorted together. OUTF and OUTS refer to the force and sense configuration of the REF70 reference buffer. The benefit of having force and sense connection is to reduce the IR loss from long trace wires at high currents. In the normal active configuration, the OUTF and OUTS are shorted together. In the REF70EVM this is done by the R1 and R2 which are 0 Ohm resistors. If R1 or R2 is removed, OUTF and OUTS must be connected in a loop by the headers J3/J7 or externally for proper operation. If the OUTF and OUTS are not connected together in a loop then the device will not operate the correct voltage.

GUID-20200824-CA0I-ZWFQ-XGC5-ZBZPMHJWRPGB-low.gif Figure 3-2 REF70 Functional Block Diagram