High-Side Switches

PROFET (PROtected Field Effect Transistors) is our High-Side smart power switch brand. It consists of a MOSFET, a gate driver with charge pump, and multiple protection and diagnosis features.

In addition, several protection features are integrated. For example, short circuit protection can protect the MOSFET if a short to ground/battery occurs.

The overvoltage protection ensures the MOSFET will not be damaged during load dump transients or other high voltage events (assuming the transient pulse energy is within specified limits). The reverse battery protection keeps the smart switch safe if the battery polarity is reversed (current may flow, but the device will not be

damaged). The current limit feature limits the maximum current that the MOSFET switch can source. This again helps to protect the switch from short to ground/battery conditions. The overtemperature protection is

enabled if the temperature of the MOSFET junction reaches unsafe levels: the switch is turned off stopping the current flow completely.

Finally, diagnostics are included so the smart switch can provide feedback to a microcontroller if a fault condition is detected.

Overtemperature and overcurrent protection

Typically, the overtemperature protection is enabled if the temperature of the junction reaches unsafe levels, e.g. where the load current might not be high enough to be detected by the diagnostics. However, maintained for some time, the load current will actually heat the device and trigger the overtemperature protection. For that, all PROFET have an integrated temperature sensor.

To understand the over temperature and overcurrent protection, let’s take a look at this graph.

Once the PROFET is on (IN=1) and the diagnosis is enable (DEN=1), it will track the accuracy of the current sense (I_IS). As you can see on the graph, in the case where the load current I_L is below the current limit, no fault will be detected. When maintained for a long time, I_L brings the junction temperature T_J to its absolute limit. The fault is detected and the over temperature protection kicks in.

In for some PROFET (like PROFET+2 (link)), there is also a dynamic overtemperature protection, that watches the dynamic variation of the junction temperature to detect a fault.

Unlike the overtemperature protection, the overcurrent protection is triggered instantaneously, as soon as the load current reaches the tripping current.

Once the protection has been triggered

Depending on the device, the protection, whether it is temperature, voltage or current, can be done:
- by limitation (the maximum current which the MOSFET high side switch can source is limited)
- by tripping (the channel is shut down).

There are two ways of register a fault conditions:

After the intervention of the protection, there are two ways to reactive the device:
- by latch (the device stays off and can only be reactivated by the microcontroller)
- by restart (once the temperature is below a certain threshold, without the need of the microcontroller).

More recent product families like PROFET+2 EPA (link) integrated an intelligent Auto-Restart function, where the channel is allowed to switch on a few times before switching off definitely, in case the conditions for switching on were not met.

Other protections

For most of the PROFET Smart Switches, other protections are also included:

• Loss of ground protection
• Reverse of polarity protection
• Undervoltage protection.

For more information, please refer to the datasheets.

Comparison to a MOSFET, diversity and versatility

Additionally to the protection and diagnostics that a MOSFET doesn’t provide, the PROFET, as integrated solution, certainly offers an ease-of-use compared to a simple MOSFET. First, it measures the load current and feedback it to the microcontroller, which is not easily available with just a MOSFET. Furthermore, thanks to its integrated charge pump, the PROFET enables you to plug it directly to a microcontroller without having to calibrate the command voltage in input of the PROFET™ (V_IN).

Thanks to the wide range of RDSon and packages within the PROFET™ portfolio, you will very likely find an answer to every of your needs. At the same time, the scalability of the PROFET™ within a sub-family enables you to keep a certain design flexibility.

Established expertise and benchmark quality

The PROFET have been commercialized for more than 20 years and have long ago legitimated their leader place on the market. By choosing Infineon high side switch solutions, you opt for the market leading products in quality, reliability and performance. Indeed, the 15 year established know-how in power switch ICS, the highest manufacturing quality and the on-going innovation make the PROFET products the most trustworthy power Switch ICs.

Innovation

With the aim of evolving with our customers’ needs and the market trends, we constantly improve our products.

• We create new technologies,
• we develop new features,
• and we decline existing products in more cost and energy effective package

to be sure to always propose a solution that is adapted your requirements.

Benefits of the newest families

The newest smart switches families (PROFET™+2 12V, SPOC™+2, Power PROFET™) inherited the sustained technological know-how of the previous families to achieve excellence. In addition to their different features, you can be sure, when opting for one of those three families, that you will:

• Save PCB-space, due to their smaller packages.
• Save cost, thanks to the integrated diode to GND and the smaller package.
• While benefiting from the advantage of a very low power dissipation, thanks to a new technology enabling the very low RDSon.
• Get an outstanding high current accuracy, increasing the safety of your system.
• Benefit from an advanced protection thanks to the intelligent Auto-Restart/Latch functions.

Benefits of the established families

Not to be outdone, the established product families (PROFET™+ and Classic PROFET™) also have their benefits:

• Using them is the insurance that you are using a performance-proofed device. Indeed R&D has worked over the years to improve their quality and manufacture, and Classic PROFET™ counts some of our most widely used parts, even as of today.
• With PROFET™+ and Classic PROFET™, you can also design for a 24V system. Indeed those two families are declined as well for 12V applications as for 24V applications.
• High energy capability
• For applications that have special voltage requirements, PROFET™+ and Classic PROFET™ offer an extended operating voltage and the possibility to support for a short time until 42V for PROFET+12V and until 65V for PROFET+24V.

How to use a PROFET?

Nominal operating Temperature: -40°c to 150°c (125°c for BTS4142N, BTS4880R, BT4141N)

Nominal operating voltage: see product table. The behavior is specified for this voltage range.

In cars and trucks, while cranking, the battery can go down drastically for a few seconds. Therefore many of the PROFET specify a minimum cranking voltage, for which the Smart Switch will still be functioning for a few seconds.

A load dump occurs when the load is suddenly disconnected. In automotive electronics, this applies to disconnecting a battery while the alternator is charging it. Most of the PROFET offer a load dump protection (42V for PROFET+ 12V, 65V for the PROFET+ 24V for example).

For more details,

Appnotes, PSPICE simulation models, Evaluation Boards and Arduino Shields are available.

Infineon’s Smart Switches portfolio is diverse and versatile. It addresses many needs and applications. Although they are automotive qualified and were first develop for automotive applications, the PROFET family are also widely used in industrial and consumer applications.

For more details, please refer to the product families.