# Tag Info

1

After searching much longer than I expected to search for this, I have come to the conclusion that this does not exist. You could easily reverse engineer it by using the reference design schematics, specifically the Sample Application Circuit diagram and the table of description of external components diagram. You may need to infer some names to put along ...

5

The crystal capacitors are called "load" capacitors, and are required as part of the oscillator circuit. The value of them depends on the specifications of the crystal being used. The 100nF capacitors on the Vcc and AVcc pins are called "decoupling" capacitors, and one is required on every power pin. They keep the power stable - without them the chip will ...

0

This will minimize "pops" on plug-in, and will keep the amp quiet when nothing's plugged into it:

0

Usually the tip is the right channel, the ring is the left channel, and the sleeve is ground. Therefore on your diagram, 1 is the (-) input, 2 is the (+) if you want to use the left channel, 5 is the (+) if you want to use the right channel. Pins 3 and 4 are connected to 2 and 5 when there is nothing connected and disconnected when something is plugged in, ...

4

If you want both the left and right channels to provide audio you need to make a little mixer. Two resistors (around 10KΩ) connected to the left and right inputs (pins 2 and 5), then joined together, will make a simple mixer. Then you link that to the LM386's IN + through a capacitor (around 10µF is usually OK). Pin 1 links direct to the IN - You ignore ...

0

1.This is being fed a 48V AC source Right on. 2.These leads are a source and a ground? Not quite. There is no specific source/ground attribution. Unless the source they get connected to is shown as grounded, they can be assumed to be floating. 3.I'm not sure what that is That is some sort of input spike limiter, such as a transzorb. 4.Two alternating ...

14

Yes. No, they're just wires going to the source. It's a MOV (Metal Oxide Varistor) to absorb surges (through-hole types look like ceramic disk capacitors). Markings on the symbol for the AC input of a bridge rectifier. A bridge rectifier (four diodes). More markings on the symbol for the DC output of the bridge rectifier.

3

It's a bridge rectifier - it consists of 4 diodes and always does its best to route the most positive part of the AC power input to the + output and likewise on the negative side. I wouldn't assume the power in is "source" and "ground" - it's more likely to be a floating (groundless) output from a transformer secondary.

0

Without the pull-down resistor the net would be floating and you would measure random states (H or L) on it. Even if you would always see a L on the pin during development that might suddenly show up as a H due to external circumstances (i.e. noise) and cause you big headaches.

2

You need something to pull the voltage down to GND when the jumper is removed. A pull down resistor, as in your second example, is the usual way. Some microcontrollers have a built-in pull-down resistor, but it consumes more power because it requires a FET to switch it in. Your second example with the resistor is probably the best option, and the only one ...

1

Yes, it is possible in Altium Designer. You can design your own custom parts and build your circuit with them. All of the circuit elements (even the IC and capcitors) in the following picture are designed by me. You can learn about creating custom component libraries in Altium Designer from here.

0

LTspice has the option of changing colors and fonts to an extent. LTspice IV

0

My personal favorites are: 1) EAGLE: While this software from CADSoft does not have simulation capabilities, it is one of the best schematic/PCB design programs I have used. The libraries are quite good and the documentation is excellent. Download link: http://www.cadsoftusa.com/download-eagle/ Image: 2) Multisim: This program from National Instruments ...

0

If you don't mind an online tool, may I sugest easyEDA:

2

Average (only slightly pathological) worst-case (20W average power out into 8 ohms at 20kHz continuous sine wave) power dissipation in the 4.7 ohm resistors will be around 120mW. Edit: In case you're curious how I got this whilst avoiding any math mistakes, well it's Saturday, and I'm lazy, and calculations look a bit too much like what I do for paid ...

1

Start with the 18k / 560 combo. Total power dissipated is V x V / R, or 25 x 25 / 18,560. That's .034 watts, so both can be 1/8 watt (25 volts is used by finding the peak voltage for a sine wave to produce 40 watts into 8 ohms. That's sqrt (2 x P x R)). For the 4.7 ohm units, consider that they are in series with .1 uF caps, and the impedance of a cap is 1 ...

1

The $R_7$-$C_8$ series impedance can be easily calculated: $$Z=R_7+Z_{C8}=R_7+\frac{1}{sC_8}=\frac{R_7C_8\cdot s + 1}{C_8\cdot s}$$ that means that when frequency is zero the impedance approaches $\infty$, i.e. $C_8$ is open, while as frequency increases the impedance lowers, and when frequency approaches $\infty$ you have $Z\rightarrow R_7$. ...

2

"Not mounted" mean that components are expected on board but are not populated on sales board. Developer usually add "not mounted " (or NM) component on sales board because it is very helpfull. For example, flash component is helpfull for testing or reparing step, but not needed for sale version of board. just think to different version of same product (for ...

3

I am going to explain this under Windows, however it should be quite similar to how it is when using Kubuntu. What you should do is plot to a SVG file and then use GIMP to convert into any raster format, PNG in this case. You can use online SVG to PNG converters with ease, too. Go to File » Plot » Plot In the dialog, select "SVG" under "Format" and ...

3

Neither the bypass capacitor C34 nor the SPI flash chip U3 has been populated on the board (since they're both inside the dashed box). The footprints for both are there, and you could add them yourself (look for the designators C34 and U3). Be sure to add the bypass capacitor C34, if it's not already there, should you decide to add the flash chip.

2

It means that if you bought the board from NXP, the SPI flash chip would not be soldered to the board but there would be PCB provision for it to be fitted should you wish to buy it and fit it yourself. That's how I read it anyway.

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