SLVS503F November 2003 – February 2020 TPS2490 , TPS2491
PRODUCTION DATA.
- 1 Features
- 2 Applications
- 3 Description
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Detailed Description
- 8 Application and Implementation
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
封裝選項(xiàng)
請參考 PDF 數(shù)據(jù)表獲取器件具體的封裝圖。
機(jī)械數(shù)據(jù) (封裝 | 引腳)
- DGS|10
散熱焊盤機(jī)械數(shù)據(jù) (封裝 | 引腳)
訂購信息
8.2.2.5 Check MOSFET SOA
Once the power limit and fault timer are chosen, it is critical to check that the FET stays within its SOA during all test conditions. During a Hot-Short the circuit breaker trips and the TPS2490 restarts into power limit until the timer runs out. In the worst case the MOSFET’s VDS will equal VIN,MAX, IDS will equal PLIM / VIN,MAX and the stress event will last for tflt. For this design example the MOSFET has 30 V, 1.83 A across it for 5.28 ms.
Based on the SOA of the CSD19532KTT, it can handle 30 V, 2.4 A for 10 ms and it can handle 30 V, 11A for 1ms. The SOA for 5.28 ms can be extrapolated by approximating SOA vs time as a power function as shown in Equation 21 through Equation 24:
Note that the SOA of a MOSFET is specified at a case temperature of 25°C, while the case temperature can be much hotter during a hot-short. The SOA should be de-rated based on TC,MAX using Equation 25 through Equation 26:
Based on this calculation the MOSFET can handle 2.41 A, 30 V for 5.28 ms at elevated case temperature, but is required to handle 1.83 A during a hot-short. This means the MOSFET will not be at risk of getting damaged during a hot-short. In general, TI recommends for the MOSFET to be able to handle a minimum of 1.3x more power than what is required during a hot-short in order to provide margin to cover the variance of the power limit and fault time.