[CHIME]

[WHOOSH]

[SWISH]

Hi. This presentation is called "Beating Discreet Solutions with Integrated Load Switches." In this presentation, we will be covering load protection, including protection during fault conditions and how it can affect the system.

Sometimes, additional circuitry needs to be added to the circuit to protect the downstream load from damage. This slide shows an example of short circuit protection done discretely. In steady state, Q1 is fully turned on and load current flows through the sensor resistor RS The voltage drop across RS generates a biased voltage, VBE, for Q2, which is used to control Q1 in a closed loop. When the load current reaches high enough to bias Q2 fully on, Q2 reduces the gate to source voltage on Q1 to limit the load current to VBE divided by RS.

Some load switches, such as the TPS22919, contain protection features that are difficult or nearly impossible to implement discretely. Features such as self-protection and recovery from short circuits and thermal shutdown help protect the system.

During transient events, such as power into short or hot short events, a discrete switching solution will become damaged without added protection circuitry. As shown below, both switching solutions are challenged with protecting the downstream circuit against a power into short condition. As shown on the left, the discrete MOSFET cannot protect itself without additional circuitry, passing over 10 amps of current downstream and becoming permanently damaged. In comparison, the load switch on the right, the TPS22929, self-protects itself and limits the downstream current to 500 milliamps.

In summary, a discrete solution here offers the benefit of adjustability in the current limit setting. Also, main discrete solutions offer fast response times to overcurrent events. However, this feature requires even more circuitry to implement discretely. Furthermore, the accuracy of the protection response time is not precise, and a sense resistor will cause additional power loss during normal DC operation.

Finally, the discrete solution does not include thermal protection, which will cause the FET to be permanently damaged if it does not remain within its safe operating area, also known as SOA.

In comparison, a load switch solution offers self-protection in a single integrated package. One device, such as the TPS22919, offers dual current limit to reduce the inrush current during startup and also provides protection during short circuit and transient events. However, the setting is not adjustable. But it can be solved by using a different protection scheme, such as an eFuse.

This concludes the load protection section of this presentation. Next, we'll be discussing size and BOM count.