# What does +Vs, -Vs and μP mean?

I have a schematic which is provided between the images. I was searching Google with no luck finding what does +Vs and -Vs mean. Also, on the schematic is a weird μP square. Even the guy in my local electronics couldn't identify it. Could someone explain these things for me?

Thanks.

• Vs is Voltage Supply -Vs is Negative Voltage Supply, obviously. uP is typically used for Mirco-Processor – Trevor_G Mar 8 '17 at 14:52
• + Voltage, - Voltage, micro processor - mu is Greek symbol – JIm Dearden Mar 8 '17 at 14:52
• The guy in your local electronics store needs to find a new job! – MCG Mar 8 '17 at 16:56
• The datasheet or application note that that drawing came from probably has a description of the circuit, and recommended operating voltages for the amplifier IC. – Peter Bennett Mar 8 '17 at 17:09
• @MCG In my country, there are people who work in such specific stores (like electronic parts or some other stuff that you should know when you're selling it) and they don't know anything. You need to exactly tell them what you want by the product number. You cannot go there and say something like: "Could you please recommend me some good sound amplifier below 15W?" – Dj Sushi Mar 10 '17 at 17:32

+Vs is the connection for the positive voltage supply. -Vs is the connection for the negative voltage supply. "μP" is very, very commonly short for "microprocessor".

• And, although he didn't ask, the short, heavy horizontal lines are ground. – WhatRoughBeast Mar 8 '17 at 14:54
• @WhatRoughBeast I knew that, anyway, thanks. But why is there also +5V if you have +Vs and -Vs? – Dj Sushi Mar 8 '17 at 14:58
• If you're asking "Why is there also a +5V?" it's because you can have as many supplies as you want. If you're asking "Why would you want to have a separate +5V as well?" it's because the digital supply will have digital noise on it. – Ignacio Vazquez-Abrams Mar 8 '17 at 15:01
• And Vs could be 12V, 15V.. whatever that circuit / chip is designed for. – Trevor_G Mar 8 '17 at 15:10
• @DjSushi uP is intended to mean any MP3 player, radio or uP sound generator with its own 5V supply implying signal range <5V (1Vtyp). – Sunnyskyguy EE75 Mar 8 '17 at 16:13

p1

$V_S = \pm20V$

p2

$V_S$ DC Supply Voltage ±25 V

p3

$V_S$ Supply Range ±5V (Min) to ±25V (Max)

And other places for split supply operation. Can also be used in single supply.

$\mu P$ = micro P = microProcessor. Sound and mute/stand-by control have to come from somewhere.

• Thank you for your answer. The sound comes in through IN (R) and IN (L). The mute goes into the base of the NPN transistor. If you know, could you please tell me what does the pin on the right of the μP unit? – Dj Sushi Mar 10 '17 at 17:26
• I wondered about that. Quick guess, biasing due to dual supply operation. I'd go with Q1 biasing on Fig 2. You are just using it to buffer processor output. – StainlessSteelRat Mar 10 '17 at 18:01