We have all seen optimistic claims for electronic products which fail to match the reality, and [Electronic Wizard] is following one up in a recent video. Can a relatively small IGBT really switch 200 A as claimed by a dubious seller? Off to the datasheet to find out!
The device in question is from Toshiba, and comes in a TO-220 package. This itself makes us pause for a minute, because we suspect the pins on a TO220 would act more like fuses at a steady 200 A.
But in the datasheet, there it is, 200 A. Which would be great, but of course it turns out that this is the instantaneous maximum current for a few microsecond pulse. Even then it’s not finished, because while the continuous current is supposed to he half that, in the datasheet it specifies a junction temperature of 25 Celsius. The cooling rig required to maintain that with this transistor passing 200 A would we think be a sight to behold, so for all intents and purposes this can’t even switch a continuous 100 A. The real figure is much less as you’d imagine, but it raises an important point. We blindly read datasheets and trust them, but sometimes we should engage brain before releasing the magic smoke.
Typo. :)
Can that little guy switch as much current as your starter solenoid?… Maybe just once, very very briefly
He doesn’t know how to read a data sheet, or a typical use case for an IGBT.
That was my first thought too. Anyone using an IGBT has in mind a very specific application and will be well aware of the constraints of the device and why things like pulse current are critical figures of merit, not just marketing fluff.
For example, one common use for an IGBT is in a lighting dimmer. Have a look at the peak current requirements of UL 1472. For an 5A typical load current, the dimmer must be able to withstand 500A for 1.4ms. Why? Inrush. Put 30 or 40 LED bulbs in parallel and all that bulk capacitance adds up. The capacitors used for synthetic load testing are pretty darn impressive.
No-one is born knowing how to read a datasheet ya donut, people read this site to learn stuff.
If you already know everything go do something useful don’t hang round in the comments making snide remarks.
Totally true. I think people that belittle others were often a victim of that behaviour growing up.
In the context of some applications specs like these are relevant and useful. High speed pulsed LED light sources for high speed photography, for example, take 100 amps for a microsecond. The duty cycle is so low the IGBT switch doesn’t even need a heat sink. Heck, the gate driver gets warmer than the output device.
Neither Electronic Wizard nor Jenny List understand what they are talking about. Spec’ing a part like that is a standard way to give the user a baseline (in conjunction with the thermal impedance spec) from which to calculate the usage limits at other current levels and pulse widths. I worked in the semiconductor industry for over thirty years and engineers who know what they’re doing rely on that kind of spec.
You give the extremes and interpolate the middle.
That said, a lot of the industry itself cannot read or understand datasheets – on purpose. See for example LED lamp specs. Lumen output and luminous efficacy are defined at Tj = 25 C, but you can print those numbers right on the box because hey, who’s checking? Here’s our brand new 400 lumen flashlight that magically runs 20 hours on a single AAA battery.
Only 400 lumens? Dude, Aliexpress is full of 20000 lumens flashlight running on a vape’s battery. I’ve seen many 4000 lumens 4K video projectors for $30 also.