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In my job I came across reading a customer schematic. I am facing trouble in identifying the marked part of the schematic, which is connected at the pins of uUSB Interface Controller.
It seems like a fuse but not very sure of the symbol, as its confidential, unfortunately the engineer did not give a part name also. Any way, it doesn't effect the design but I am eager to know about it out of interest.
The design is of a mobile phone.
The flat black lines are the various circuit grounds, and the voltage pins are labelled at the IC symbol, so you are correct in your assumption that this is the positive supply rail also.
The datasheet is pretty unclear - there is no pinout table, but there is a diagram of the IC pins with labels, so you can number them starting from pin 1 at the left, then match these up with the numbers on the example circuit.
We can see from the above pin 6 is Vcc 1 (positive rail 1) and pin 20 is Vcc 2 (positive rail 2) Also pins 2,8,18 and 24 are power ground pins. Pin 13 is S-GND, and Pin 16 is AC-GND. The application notes in the datasheet describe the use of all these pins. Here is a snippet mentioning the use of AC-GND:
As shown by Figure 14, all the TDA7385’s main sections, such as Inputs, Outputs AND ACGND (pin 16) are internally biased at half supply voltage level (Vs/2), which is derived from the Supply Voltage Rejection (SVR) block. In this way no current flows through the internal feedback network. The AC-GND is common to all the 4 amplifiers and represents the connection point of all the inverting inputs. Both individual inputs and AC-GND are connected to Vs/2 (SVR) by means of 100 kO resistors. To ensure proper operation and high supply voltage rejection, it is of fundamental importance to provide a good impedance matching between Inputs and AC-GROUND terminations. This implies that C1 , C2 , C3 , C4 , C5 capacitors have to carry the same nominal value and their tolerance should never exceed ± 10 %.
I assume that S-GND is signal ground, and the datasheet covers this and the output stage power pins:
To simplify pc-board layout designs, each amplifier stage has its own power ground externally accessible (pins 2,8,18,24) and one supply voltage pin for each couple of them. Even more important, this makes it possible to achieve the highest possible degree of separation among the channels, with remarkable benefits in terms of cross-talk and distortion features. About the layout grounding, it is particularly important to connect the AC-GND capacitor (C5 ) to the signal GND, as close as possible to the audio inputs ground: this will guarantee high rejection of any common mode spurious signals. The SVR capacitor (C6 ) has also to be connected to the signal GND. Supply filtering elements (C7 , C8 ) have naturally to be connected to the power-ground and located as close as possible to the Vs pins.
Looking at the example layout, we can see how the separate inputs with signal ground, and out power pins are used to keep each channel isolated on the board, and connecting to the supply separately to from a star grounding network.
Much trial and error and frying of diodes later (best to draw a veil), this is what I know:
When I unscrewed the gadget from the camera chassis, it seemed to work properly, but when I put it back in it just slammed fully open like before. The gadget is made with moving and static coils arranged very snugly in a small metal barrel case. I eventually figured out that one of the static coils was touching the case, causing S-S to short to ground when the gadget was screwed on to the chassis. To my surprise I was able to prise the cap off the barrel, stick a bit of insulating tape in there, and put it all back together without actually destroying it. I now have a working camera (except for the remaining problem of recalibrating the exposure - adjust variable resistor P1A - without a known intensity light source).
Best Answer
It does not get the same signal i.e JIG_ON_N.
Actually it is shutdown or reset button that requires a short push (push button) that is short this two wires. Search on Eagle
Some times, schematic editor softwares using strange symbols that are not standard for industry.