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FAN8082 schematic help. What does PVCC, VCC, SVCC stand for and what is it that I am connecting them to? Answered

I have a FAN8082 chip and do not understand all of the abbreviations on the schematic.  I have Googled, but what I have found is beyond my vocabulary.  What is PVCC, VCC, and SVCC?  What connects to them? I am assuming it is the power for the motor itself. What do the resister and capacitor accomplish?  

Attached is the FAN8082 schematic and boxed in red is the area I am confused about

Thank you very much.


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Jack A Lopez
Jack A Lopez

Best Answer 8 years ago

I am guessing that you and I are looking at the same data sheet.  In the words that follow I am going to mention page numbers and tables and stuff from that data sheet and naively assume it's the same data sheet you're looking at.

 VCC means "supply voltage".  There is some history as to how that name came about, based on ICs made out of bipolar junction transistors (and VCC being the highest "collector" voltage, and VEE= ground being  the lowest "emitter" voltage) but I'm not going try to explain where the name came from.  In the context of your IC here, the phrase "VCC" basically means "supply voltage".

Also for this IC there are sort of two DC supplies.  One is for providing power to the motor, and it is labeled PVCC ("power VCC").  The other is, I am guessing, for the IC itself, for those functions not related to powering the motor, like the power needed for its little logic and voltage measuring circuits. This other supply pin is labeled SVCC, which I guess is intended to mean "signal VCC" or "signal supply"

BTW, these pins are given their funny names on page 2 of the data sheet, in the table labeled "Pin Definitions".

Also if you look at page 8 of the data sheet, at the diagram labeled "4. Drive Output Circuit", you can see what PVCC, the motor supply,  is actually connected to.  PVCC is connected to the collectors of Q2 and Q5, the emitters of which get connected to the motor.

Anyway, for that little network that you've drawn a box around, the R (labeled RS), the C, and pin 7 (PVCC) and pin 6 (SVCC), I think the intent of that circuit is sort of low pass R*C filter, to make sure the voltage at pin 6 (SVCC, "signal supply") is clean and quiet, or more clean and quiet than the motor supply,  pin 7 (PVCC).

Also note that resistor, crypically named RS, is in series with the motor.  If VCC is the positive (+) side of  your battery, current flowing to the motor has to flow through RS, as they've got it wired there, and that might be intentional. That is to say RS was chosen to sort of limit current to the motor.

Regarding the expected size of RS, I looked up a similar IC named KA3082, also made by Fairchild(r), and the example application circuit for that IC is almost identical to this one, except that data sheet just has PVCC and SVCC connected by a 10 ohm resistor.  So that might be about the size  of RS they were planning on.


8 years ago

VCC is going to the positive lead of your power source. VCC stands for Common Collector Voltage.