SLLU379 March   2024 THVD4421

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1  Power Requirements
    2. 2.2  Board Setup and Operation
    3. 2.3  Header and Jumper Information
    4. 2.4  Resistor Information
    5. 2.5  Capacitor Information
    6. 2.6  LED Information
    7. 2.7  IC Information
    8. 2.8  Test Points
    9. 2.9  Assembly Instructions
    10. 2.10 Best Practices
  9. 3Hardware Design Files
    1. 3.1 Schematics
    2. 3.2 PCB Layouts
    3. 3.3 Bill of Materials (BOM)
  10. 4Additional Information
    1. 4.1 Known Hardware or Software Issues
    2. 4.2 Trademarks
  11. 5References

2.1 Power Requirements

THVD4421 IC Variant Considerations

The most modern variant of the THVD4421RHB has pin 7 of the IC as no connect (NC). However, this EVM can include the original pinout of the THVD4421RHb, which is slightly different. The original pinout has pin 7 connected to VCC. To remedy multiple possible pinouts for the THVD4421, jumper J15 must be configured before operation. With J6 oriented at the top left of the board, J15 is to the bottom left of U1.

Table 2-1 Variant Considerations
Component ID Comment
J15 – Original pinout THVD4421 Shunt J15 to connect VCC to pin 7
J15 – Current pinout THVD4421 Leave J15 open

Single Supply Operation (Logic Supply Equals Main Voltage Supply)

The THVD4421 Transceiver in the RHB (VQFN) package from TI has an additional logic supply pin, VIO. This is used to power the internal digital logic circuits inside of the device. In single supply operation mode for the THVD4421RHB, the VIO pin must be shorted to VCC by shorting the header pins of J8, so that the digital circuits are properly powered.

Table 2-2 Single Supply Operation
Component ID Comment
J6 VCC power terminal – Attach voltage source of 3V to 5.5V to terminal block.
J7 VIO power terminal – leave open for single supply operation.
J8 Shunted for single supply operation.
J9 Shunted for applications with no separation between EARTH and GND.

To apply power onto the board, VCC is applied through the J6 terminal, with the board oriented so that J1 is on the top left side of the board. The signals are, from right to left, VCC, GND, EARTH. The EARTH and GND distinction are used to help the end user determine operational qualities with respect to ground potential differences. If the user wants testing methods on reducing ground loop current, then install a resistor on pad R16. For applications without a separate EARTH connection, EARTH and GND can be shorted together by jumper J9. Bulk supply decoupling capacitors can be found on the underside of the board.

Dual Supply Operation (Separate Digital Logic and Driver Supplies)

The THVD4421 transceiver in the RHB (VQFN) package from TI has an additional logic supply pin, VIO. This is used to power the internal digital logic circuits inside of the device. In dual supply operation, the digital circuit supply, VIO, supplies the logic signal pins (L1 – L4) and the control signal pins (SLR, DIR, M0, M1, TERM_TX, TERM_RX, and /SHDN). This supply can operate from 1.65V to 5.5V to allow controllers to communicate with the transceiver at 2.5V and 1.8V logic levels. J8 must be left open for dual supply operation.

Table 2-3 Dual Supply Operation
Component ID Comment
J6 VCC power terminal – Attach voltage source of 3V to 5.5V to terminal block.
J7 VIO power terminal – Attach voltage source of 1.65V to 5.5V to terminal block.
J8 Left open for dual supply operation.
J9 Shunted for applications with no separation between EARTH and GND.

Powering the board up is similar to the single supply operation. J6 is powered as described in Table 3-2. Using the same orientation as before (J6 at top left of the board), the inputs for the VIO power terminal (J7) are similar VCC (J6); from right to left is EARTH, GND, VIO. Bulk supply decoupling capacitors can be found on the underside of the board. For applications without a separate EARTH connection, GND and EARTH can be shorted by shunting J9.