npm1300 load switch and LDO

Question

Hello, 
 Currently designing in the npm1300 into a project and want to understand better the difference between the LDO and the load switch. In the example schematics the LDO is shown with an output capacitance of 20uF while the load switch has just 1uF. Trying to understand why. Is the load switch just an LDO that can be switched on and off, like a high side switch? Is there any difference between the efficiency of the load switch and the LDO?

Menon · Accepted Answer

Hello, 
 In the example schematics the LDO is shown with an output capacitance of 20uF while the load switch has just 1uF. 
 This is mentioned in the section about the LDO and load switch output capacitors . In LDO mode, the regulator requires a larger capacitor (around 20 µF) to remain stable and keep the output voltage steady when the load changes quickly. In contrast, in load-switch mode, the device simply acts as an on/off switch, so only a small capacitor (about 1 µF) is needed to ensure smooth turn-on and to avoid sudden changes in current. Also see the section Load Switches / LDO Regulators . 
 Is the load switch just an LDO that can be switched on and off, like a high side switch? I 
 No, I believe the section I pointed out already explains this. 
 Is there any difference between the efficiency of the load switch and the LDO? 
 There isn’t an efficiency curve provided, but you can compare the electrical specifications for load-switch mode and LDO mode to get an idea. See the Electrical Specification section under 6.4.1 (inside the data sheet ):

In load-switch mode, you can pass up to 100 mA.

In LDO mode, you’re limited to 50 mA at higher Vout, and 10 mA at lower Vout.

Kind Regards, 
 Abhijith

npm1300 load switch and LDO

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