ZHCSHM2D June 2018 – April 2025 TPS746-Q1
PRODUCTION DATA
- 1
- 1 特性
- 2 應用
- 3 說明
- 4 Pin Configuration and Functions
- 5 Specifications
- 6 Detailed Description
- 7 Application and Implementation
- 8 Device and Documentation Support
- 9 Revision History
- 10Mechanical, Packaging, and Orderable Information
封裝選項
機械數據 (封裝 | 引腳)
散熱焊盤機械數據 (封裝 | 引腳)
訂購信息
7.1.4 Exiting Dropout
Some applications have transients that place the LDO into dropout, such as slower ramps on VIN during start-up. As with other LDOs, the output may overshoot on recovery from these conditions. A ramping input supply causes an LDO to overshoot on start-up, as shown in Figure 7-2, when the slew rate and voltage levels are in the correct range. Use an enable signal to avoid this condition.
Figure 7-2 Start-Up Into DropoutLine transients out of dropout can also cause overshoot on the output of the regulator. These overshoots are caused by the error amplifier having to drive the gate capacitance of the pass element and bring the gate back to the correct voltage for proper regulation. Figure 7-3 illustrates what is happening internally with the gate voltage and how overshoot can be caused during operation. When the LDO is placed in dropout, the gate voltage (VGS) is pulled all the way down to ground to give the pass device the lowest on-resistance as possible. However, if a line transient occurs when the device is in dropout, the loop is not in regulation and can cause the output to overshoot until the loop responds and the output current pulls the output voltage back down into regulation. If these transients are not acceptable, then continue to add input capacitance in the system until the transient is slow enough to reduce the overshoot.
Figure 7-3 Line Transients From
Dropout