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123 Threads found on edaboard.com: Signal Ground And Power Ground
Hi, In multilayer PCB layout, it is very common to have dedicated power and ground plane layers during layout. This results in good signal integrity. But in IC layout, I have rarely seen anyone using a particular metal layer solely for power or ground (...)
Hi all, I have a 2MHz/5V signal. I want to shift its level at 12V then transmit it over a wire (70cm long) to another board. On the other end i would like to shift level of 12V signal back to 5V. I tried CD4504B. But the signal get distorted ..... and duty cycle changed to 60% from 50%. Kindly suggest me an alternate (...)
Every time you switch that capacitance you spike either the power or the ground rail and this has to damp out, if indeed it can; ground kicks especially get into all kinds of other things (like your reference voltage, your current sense, etc.) and can initiate large (...)
Hello, I am designing a magneto resistive encoder. For the magneto resistive sensor I am using KMXP5000 sensor, for further signal processing I took IC-TW8 interpolator. The problem I have is the noise in power supply, the noise is only there when IC-TW8 interpolation IC is running, if I reset it the noise disappears. I included the image from
I build amplifiers at times for fun but I always have a problem with them, I get small hums and a higher pitch sound from tweeters, at times I realize when I touch like pots the humming gets higher and if I touch like a speaker wire the humming goes down or stops, I normally wonder if its grounding issues as I don't think I know
Hi everyone I recently submitted a new design for emc testing. Its passed all but the radiated emissions testing. The design incorporates a camera connected to a controller. The camera is powered by 24vdc down a 15 m power cable. When tested for emissions there are some pretty significant peaks in the results. 128241[/AT
:) Hi My Friends... I have a circuit with LM386 Amplifier to amp the signal of VS1003 Left and Right channels. The question is, when i put the headphone cable (example iPhone 4) to the output stage, i dont hear any noise, but when i use another headphone (iPhone 5S) i hear noise of "Hum-Hum-Hum-...". Probably for the old headphone the sensiti
like they said, you have to solve this at the source, not along some 2" long trace. Start with bypass caps right a the chip that is making the signal. 1000 PF in Parallel with 0.1 uF, as close as possible to the power supply pin and the ground pin. that will keep the circulating (...)
Which connector switch Sleeve? You are wondering why DC ground current causes ground noise? with 50mOhm spec @1A or after aging? or with low level signal or with inductive grounds and unshielded connector and signals? (...)
AC supply probably has lots of 100Hz ripple. Measure it with no load and full load signal. Each power amp is probably oscillating above 100Khz causing overheating. If it gets hot with no load, put 2.7Ohm 0.47uF as indicated in specs or similar series snubber on each output to ground. If DC out is not (...)
signal or power diode rated for Icoil is always applied across coil in reverse. This shunts the spike to Vdiode + Icoil* Rdiode (ESR) when switched off. This EMI can be minimized by reducing the loop area of the coil wires using twisted pairs or shlelded pair with care on ground current swing and choice (...)
Why do you need a dual-polarity power supply? ANY AC opamp circuit will work with a single supply voltage if its (+) input is biased at about half the supply voltage and the signal input, output and feedback to ground parts are capacitor-coupled. Here is an example:
Either voltage or current mode bias distribution has its plusses and minuses. With voltage mode you worry about ground offsets and cross-chip VT gradients. With current mode, especially very low currents (hence high net impedance) you worry about signal coupling from digital aggressors and (...)
If Pin 5 does not switch from low to V+, you may have to invert ground contact to create this signal. Cant tell from your description what conditions exist before after power is applied when inserted.
Hi all, As far i know, balanced pcb stackup follows 1. signal layer should have adjacent power/ground layers 2. from center of the board(cross-sectional) top and bottom should have same amount or weight of copper and the di-electrics. If i am deviated from the correct concept (...)
Endcap cells are inserted to fullfill well tie off specifications for the cell rows. Endcaps dont have signal connectivity. They only have connectivity to power and ground distribution in the design. Endcaps have a fixed attribute and cannot be moved by optimization steps. Endcaps are placed (...)
ground and Vcc are the same to a signal because the power supply has a very low resistance and is bypassed with a capacitor.
I have a system where I have sensitive high gain optical amplifiers. The amplifiers has gain around 6M times. In the same system, I also have a wifi module. The construction of the system is such that Wifi - module (TOP) ------------------ Plastic divider Analog Front End (Bottom) The AFE picks up wifi during receive. The AFE doesn't go up
The audio circuit in the post #8 will not work: 1) The 741 opamp needs its (+) input biased at half the supply voltage so its output can swing up and DOWN with the audio signal. Its output needs to be capacitor-coupled to the volume control. 2) The LM386 power amp is missing the important series RC to ground (...)
The question doesn't seem to make sense, you have a floating input source, so you can make either positive or negative output your common ground, which simply "combines negative and positive rectified signal".
The "virtual ground generator" would mainly provide the difference between MAX038 positive and negative supply + signal amplifier output current. So it can basically work. Nevertheless it's a bad power supply design that should be replaced by something more state-of-the-art. It's a sufficient reason (...)
The junction of R4 and R5 will produce much less noise if it has a filtering capacitor to ground. You do not need a buffer at the input of the simple filter. This circuit uses signal voltage, not signal power. If you match impedances then the signal level drops to half, (...)
There are several issues with this circuit. - The first stage needs a dual power supply. uA741 would need it anyway for a ground referenced signal, and you also need it because the signal itself is bipolar. - The second stage implements a peak detector, which is not suitable for a basic AC (...)
Hey, I am trying to install a CCTV system for a friend. He has a powercable through the ground to about 60m away. From that point the whole rear of his house can be overlooked with a single IR-cam. :idea: Now we don't want to dig up his garden and he needs the cable to power his garden lights as well. I (...)
How many stitch vias should I add to a PCB? I have added stich vias close to where signals changes reference planes and also near all bypass capacitors. But how many stitch vias besides this should I add? Any web links where I can read more about this? Any books that explains these kind of quastions?
hey... iam trying to build dc_dc converter with tow mosfet so i must use ir2110 driver, i make the simple test circuit below with tow pwm signal 50% ,first i isolated the Vss and the com, i put the Vss ,Sd and the microcontroller at the same ground ,and i connect the COM with the (...)
I have a mixed-signal layout I need to complete. It has an 8-bit micro feeding about 16 analog switches/multiplexers which controls a bunch of analog (audio) circuitry. I know from past experience that if I'm not careful with the layout, including the placement of the power and ground planes, I can get (...)
and what sort of signal?
I have a mixed signal board with +5 / -5 split planes. How important is it that my capacitors (that are connected to -5 and +5 used for decoupling and stuff) fall directly between the split plane so that each plate is above the corresponding plane? Can the cap be placed anywhere? What if they are reversed and above (...)
I am looking at a chip spec. It uses a single wire to do both power supply and digital serial input/output. This pin, plus a ground pin, are all the pins this chip has. In normal use, the power pin is connected to VDD thru a pull-up resistor. The digital signal can be transmitted on this (...)
Greetings. I have a 6 layer mixed signal board with the following stackup. top ground plane Mid layer Mid layer power plane bottom In one corner of the board i have some really sensitive analog circuitry encased within a shield box. I'm wondering how beneficial it is for me to put (...)
I have a trivial question about board stackups between 4 layers and 2 layers pcb's All of my training documents use 4 layer boards. Using layer 1: top, layer 2: ground, layer 3: power, layer 4: bottom. I have a few questions about the board stackup. 1) The top layer is a signal layer? 2) The (...)
A digital ground is faster: means the digital signal arrives to its ground state faster than an analog transition.
Hi All, I am using Proteus 7.7 and I would like to separate my signal, power and analogue grounds by using a star point. I am designing a four layer PCB so the star point would be best placed on an internal layer, I have been able to create a new component with pins overlapping for (...)
Totally agree with edpalmer42. I would use the twisted pair for power and keep the shield just for shielding. The twisted pair will help to contain any power supply noise. If you use the shield for power ground, you might radiate more electrical noise either outside the unit or into the (...)
1. How can I add separate via in PADS Layout software for return current path for signal trace, which changes the layer? I know only how to add via while routing. 2. As I understood, via is used for return current path when both reference planes are GND. But what should I do when the reference plane is changed from GND to power plane? Thank you
Hi, I'm designing mixed signal circuits. digital circuits are synthesized by Design Compiler and P&R is performed by using Astro. In the floorplan stage, i made core area, power/ground ring, horizontal power/ground rail for (...)
by differences in definitions of 1 and 0 levels between the two is that we need an interface Standard TTL circuits operate with a 5-volt power supply. A TTL input signal is defined as "low" when between 0 V and 0.8 V with respect to the ground terminal, and (...)
TVS is a high speed fat diode intended for ESD clamp on DC and signal lines. MOV's are higher capacitance and low R, so work for power line transients on AC to Neutral.
You can communicate data on the DC power line by using capacitor to block the DC voltage component and also have to put a inductor choke to every end of the power line including the power supply output so that no any filter capacitor can bypass the data to ground and the (...)
Hello ppl, I have a 4 layer PCB stack up and the corresponding .dxf file imported in ADS. My doubt is that I know that layer 1 which is signal trace 1 corresponds to the .dxf layer Trace_01 and same is the case with signal trace 2 i.e Trace_04. Now between these two layers I have ground (...)
Assuming there's a strip line with image plane(ground or power) below it, when the signal current on the strip line changes, it induces "eddy current" down on the surface of image plane below. I know what image planes do in PCB. They provide elements with voltage and current. So, there must be existing (...)
A latch with no clock signal and no power & ground? No, it is not possible! You need 5 pins including power & ground. Keith.
hi what is the difference between power ground and signal ground in DC DC converters? What will happen if we connect them together? Please explain in detail.
Sorry, this may belong in the PCB layout forum, but it's also related to power electronics so I figured i'd post here. I'm working on a PCB that has three DC/DC converters on it. I did a first cut using a 2 layer board and I'm having trouble getting two of the converters to operate at full load. I spoke with the tech support from the IC compan
Has anybody tried to use separate analog and digital ground and power to reduce the noise with the APR9600. I tested noise by recording external input with no signal. I then can hear some noise when I playback that recording. My demo board has both analog and digital (...)
Zuzu The first thing you need to do is to determine how many signal layers you need. Then find out how many power/ground layers you need for your power distribution and impedance layers. Also find out what core and prepeg thicknesses your pcb fabricator has in stock. ( (...)
enjunear , you miss Art of Analog Design ? Microwave Theory Book : test signal to our circuit and out S Parameters , Black Box .
YES, if your signal ground is a common reference ground for all ICs, including controller, and it is the only signal return path back to the source (i.e. power ground) However, wherever possible, try to use a Star Topology, (...)
The general problem with separate GND planes is where to connect them. You'll notice, that data sheets of mixed signal devices, e.g. ADC, DAC, ?Ps with analog functions usually claim to get the separate GNDs connected directly at their respective pins. It's a clever suggestion for trivial evaluation boards, that utilize only one mixed signal chip.