SLVAEQ2 April   2020 TPS2549-Q1 , TPS254900-Q1 , TPS254900A-Q1 , TPS2556-Q1 , TPS2557-Q1 , TPS2559-Q1 , TPS25830-Q1 , TPS25831-Q1 , TPS25832-Q1 , TPS25833-Q1 , TPS25840-Q1 , TPS25842-Q1

 

  1.   How to Pass MFi Overcurrent Protection Test With USB Charger and Switch Device
    1.     Trademarks
    2. 1 The Instruction of MFi OCP Requirement
    3. 2 Test Standard and Requirements
    4. 3 The Solution to Pass MFi OCP Test
      1. 3.1 Solution 1: Increasing Current Limit Point Higher Than 1.6*Ia
      2. 3.2 Solution 2: Paralleling RC With Rlimit to Delay the Current Limit Response
        1. 3.2.1 For the 1.5A USB Port With External FET
        2. 3.2.2 For the 1.5A Port Without External FET
        3. 3.2.3 For 2.1A USB Port With External FET
        4. 3.2.4 For 2.1A USB Port Without External FET
        5. 3.2.5 For 2.4A USB Port With External FET
        6. 3.2.6 For 2.4A USB Port Without External FET
        7. 3.2.7 For 3A USB Port With External FET
        8. 3.2.8 For 3A USB Port Without FET
    5. 4 Summary
    6. 5 References

2 Test Standard and Requirements

The following test setup and requirements are based on the TPS2583X/4X-Q1 EVM to pass MFi OCP test:

  1. The test load waveform is shown in Figure 2.
  2. The test setup between the TPS2583x/4x-Q1 EVM and E-load includes lightning cable, test connection board. The setup as Figure 3.
  3. In practice, whether the test is passed is determined by whether the voltage at the E-load drops to 0 V.
  4. Due to the voltage drop on the cable and some characteristic of the connection board, the output voltage of TPS2583x/4x-Q1 should be higher to pass the test.
figure 1.tifFigure 2. Load Waveform of MFi OCP Test
figure 2.tifFigure 3. TPS2583x/4x-Q1 EVM MFi OCP Test Setup