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
-
How to Pass MFi Overcurrent Protection Test With USB Charger and Switch Device
- Trademarks
- 1 The Instruction of MFi OCP Requirement
- 2 Test Standard and Requirements
- 3
The Solution to Pass MFi OCP Test
- 3.1 Solution 1: Increasing Current Limit Point Higher Than 1.6*Ia
- 3.2
Solution 2: Paralleling RC With Rlimit to Delay the Current Limit Response
- 3.2.1 For the 1.5A USB Port With External FET
- 3.2.2 For the 1.5A Port Without External FET
- 3.2.3 For 2.1A USB Port With External FET
- 3.2.4 For 2.1A USB Port Without External FET
- 3.2.5 For 2.4A USB Port With External FET
- 3.2.6 For 2.4A USB Port Without External FET
- 3.2.7 For 3A USB Port With External FET
- 3.2.8 For 3A USB Port Without FET
- 4 Summary
- 5 References
3.2.5 For 2.4A USB Port With External FET
For 2.4A USB port with external FET, set current limit to 2.88A with external FET, parallel 6.65kΩ+82nF RC with 6.65kΩ, the Vbus doesn’t have obvious drop under the certification load.
Figure 15. Set 2.88A Current Limit for 2.4A Port With External FET