Purpose of Dual PMOS common source configuration

[dcoaster]

Hi all,
I'm starting a design of a power controller using the LTC 4417 chip (https://www.linear.com/product/LTC4417). In the typical application, it shows the use of dual PMOS in a common source configuration. What exactly is the purpose of using two versus just a single PMOS? Is it simply for the voltage sense?

Thanks!

 

[juicedry]

For bi-directional current flow. You use them generally as a load switch and it allows very low conduction losses in either direction when on. Then when you turn it off, it blocks in both directions, as you have the inherent drain-source body diode back to back. Otherwise called a bat fet for battery fet, as you find them as the main switch fgoing into Li Ion battery charging.