6 September 2019
Before you buy a car, you probably take it on a test drive. There are on-line “virtual test drives”, but they are usually just videos showing someone else driving the car … there is no user interaction! That is no longer the case when buying automotive electronics components. With SystemVision Cloud, semiconductor manufacturers can provide far more realistic, interactive “test drives” for their customers.
ON Semiconductor has recently provided a high-fidelity model of their NCV84160 High-Side Driver. That device has many built-in functions and protection features beneficial to automotive lamp, solenoid and other driver applications. These include:
- Built-in short-circuit and inrush current limiting
- Built-in over-temperature protection with automatic restart
- Built-in voltage clamping when turning off inductive loads
- Built-in load current sensing (i.e. no sense resistor needed in the solenoid power circuit)
These built-in features can reduce overall circuit complexity and increase reliability for your lamp and solenoid designs.
Operating Voltage Range
4.5 to 28V
RDSon (max) at Tj = 25C
Output Current Limit
You can learn much more about the NCV84160 here
The Lamp Driver circuit shown below is a “Live” design, ready for you to “test drive”. That is, you can change any of the parameters shown in blue, to match specific lamp characteristics and operating conditions of your system. Then run a new simulation and see the results of your changes. You can also move the waveform probes around and see all other signals in the design (i.e. voltages on wires as well and components’ internal variables).
A 10 Watt/10A inrush current bulb (R10W) is an ideal automotive bulb load for the NCV84160 as shown above. However, you can see what would happen if the vehicle owner decides to make the car interior brighter by connecting a 55 Watt/63A inrush current automotive headlamp into the interior lamp socket! After making those changes, just push the green "Play" arrow and a new simulation will be run. In about 30 seconds, the new simulation results will show that the NCV84160 limits the peak current to under 12A, and eventually enters on/off thermal limit cycling at a reduced average current level, helping protect the upstream power distribution system from overload.
(Note also that the simulation automatically stops after 10 thermal limit cycles, to reduce simulation time for this indefinite failure mode operating condition)
A good “virtual test drive” platform for cars would let you choose “on-road” or “off-road”, depending on your intended use of the vehicle. Likewise, if you are designing a solenoid actuation system and not a lighting system, then you may prefer the following “test drive”:
Like the lamp driver application, you can change any system parameter in blue and run a new simulation to see the effect. This design illustrates the active clamping and the current sensing features of the NCV84160. The magenta waveform is zoomed in on the solenoid voltage at the device turn-off time, and the -34.4V clamping is observed. The red waveform is the current sense output, which provides a current that is 1/450th of the actual solenoid current (dark blue waveform). The current sense voltage, which can be scaled by r1, provides a useful monitor signal for solenoid performance. For example, if you change the solenoid stroke to 5m (meters) and t_response to 10m (seconds), to model a larger and heavier solenoid, you will see a significant change to the v_cs "signature" coming from the NCV84160.
Next: Start Your Own Driver Design
One final comment: It doesn’t need to end with these Application Examples! You can start with either one of these design, push the yellow “View in systemvision.com” button in the lower right corner of the schematic, and you will see that circuit in the full SystemVision Cloud design environment. From there, you can hit the “Save As” button* to copy that design and then modify it as you like. Or start with a new blank schematic and build your own application circuit. You’ll find the NCV84160 model in our Partner Library (ON Semiconductor -> Protected FETs), as well as hundreds of other general and supplier provided models that can be used in your design.
*Just login or create a free account, and you’ll be all set to use this powerful on-line design, modeling and simulation environment for your own creations.