SLVAEQ7 April   2020 TPS55288 , TPS65987D

 

  1.   USB Type C Power Delivery Source with TPS65987D and TPS55288
    1.     Trademarks
    2. 1 Introduction
    3. 2 Implementation
      1. 2.1 GPIOs for setting voltage
      2. 2.2 I2C for setting voltage
    4. 3 Test Results
    5. 4 References

Test Results

The overall test setup consisting of the TPS55288 and the TPS65987D EVM is shown in Figure 5.

Figure 5. Block Diagram

This setup allows easy evaluation of this combination.

Figure 6. Startup behavior

In Figure 6 is shown how the system behaves when a device gets connected. It can be seen before a device is connected, the VBus line is unpowered. With a first reaction on the CC line, the voltage on VBus gets enabled but is still at 5 V. During the voltage is at 5 V, communication on the CC line happens. After this exchange about capabilities and negotiating PDO 4 with 20 V, the TPS65987D sends out the configured message to switch the voltage to 20 V. It can be seen that the VBus voltage increases to 20 V.