SLLU356 September   2022 THVD1424

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Information on Cautions and Warnings
  5. 3Board Description
    1. 3.1 Board Component Overview
      1. 3.1.1 Powering the Boarde
        1. 3.1.1.1 Single Supply Operation
        2. 3.1.1.2 Dual Supply Operation (Separate Digital Logic and Driver supplies)
        3. 3.1.1.3 Default Operation Mode
        4. 3.1.1.4 Single Ended Bus Modification Operational Modes
  6. 4Design Documents
    1. 4.1 Schematics
    2. 4.2 Board Layout
    3. 4.3 Bill Of Materials
  7. 5Revision History

3.1.1.1 Single Supply Operation

The THVD1424 has both a VCC pin (used for the RS-485 bus pins) and VL pin (Used for console facing pins). In single supply operation mode for the THVD1424 the VL pin should be shorted to VCC by shorting the J7 header pins, so that the digital logic circuits connected to the Logic supply are properly powered.

Table 3-2 Single Supply Operation Configuration Table
Component ID Comment
J5 Leave VL terminal Open
J6 Attach VCC (3 V to 5.5 V) to Terminal
J7 Short Jumper to make sure VL = VCC
C2, C3, C4, and C5 Leave Uninstalled
C6 and C8 If More Decoupling Capacitance is Desired Attach Capacitors to C6 and C8
R15 Install Resistor if Low impedance pathway between GND and EARTH is desired

To apply power onto the board, VCC is applied through the J6 terminal. With the board oriented with J6 on the top of the board, as shown in figure 1.1, the signals are, from right to left, EARTH, GND, and VCC. The EARTH and GND distinction are used to help the end user determine operational qualities w.r.t. ground potential differences. If testing methods on reducing ground loop current install a resistor on pad R15. Check data sheet for proper powering considerations as this will either recommend 3.3V, 5V or 3.3V to 5V.