Hello, my name’s Kevin Cavell and I’m a Product Manager at Keysight Technologies.
Today I’d like to demonstrate the seamless measurement rating feature of our N6780 series
SMUs.
I have an N6781A SMU installed in output three of the mainframe.
Over to the side here, I have our new N6785A higher power SMU that goes up to eight amps.
This N6781A that I have installed goes up to three amps and four of the tests that we’re
going to be doing today, the N6781A is sufficient.
So we’re going to be testing the power consumption of a tire pressure gauge.
You’ll find this in most modern vehicles where it reports the tire pressure gauge to
the vehicle.
Instead of reporting it to the vehicle, we’ll get the tire pressure measurement on this
device here.
So we’ll be using the DC power analyzer mainframe with the SMU installed, along with
the 14585A software.
So let’s take a look at the tire pressure gauge’s power consumption.
So here we get a closer look at the 14585A control and analysis software for advanced
power supplies.
On the left, you can see the instrument control fly out window gives us a representation of
the N6705B DC power analyzer.
In output three, we have the N6781A SMU programmed to three volts for the battery voltage going
to the tire pressure gauge and you can see that current around 400 nA is being drawn.
However, every once in a while, you can see this change to a higher level and if we want
to take a closer look, we can use the data logger.
If we click on data logger, it takes us to a scope like screen where we can set it up
five seconds per division, total acquisition time of 50 seconds.
And then we would just click play on data logger and it would start taking measurements.
However, I’ve done that already so we get a look at what the wave form looks like.
You can see for most of the time, the tire pressure gauge is in a sleep state conserving
the battery and then every so often, it wakes up to transmit data to the console.
If we wanted to see how long between each transmit, we can move our markers roughly
to this low level period and the delta is about 9.6 seconds and the average current
is extremely low.
You can see 477 nA in this period of time.
If we wanted to see what this peak current during transmit was, we can do same thing
and move our markers roughly around that peak and you can see the maximum in between the
markers is 5.6 milliamps.
So that’s the transmit current and the average is about 240 uA.
So the data logger with the markers really gives the designer great insight into the
power consumption of the device, in this case, the tire pressure gauge which is extremely
low power and the designer can get an idea of how long their design might last on a particular
battery.
Again, this really gives great insight by measuring extremely low currents and extremely
high currents within one pass and that’s made possible by the seamless measurement
ranging technology that we have in our N6781A SMU.
So we got to see the current drain of a tire pressure gauge using the Keysight solution.
Again, we used the N6781A SMU that goes up to three amps, but we also have our new N6785A
SMU that goes up to eight amps for testing higher power devices.
Thanks for watching.