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any thing else can cause this buzz ? An old and 'unprofessional' technique, but occasionally very effective in determining the cause of audible noise emitted in the power supply, is to put your finger on some board components and assess whether it has overshadowed a bit loudness. Needless to mention that this must b
I have made a simple transmission gate with one input (for signal with sinusiodal voltage input V0), a control (logic 0/1 to make switch On /OFF, with dc voltgae) and an output across a resistor. I want to do the noise analysis of this circuit. 1) Since it is not a differential circuit, how can i have positive and negative output nodes, for outpu
switch off means floating signal, unless the node is pulled down by some means. Any reason why not to expect arbitrary signals on the floating node? Jumping into details, we would ask for the type of observed signal (DC, noise, known interfering source)
R9 noise is shorted by U2 when the switch is closed -> noise contribution irrelevant.
Hello! I'm planning to use a circuit attached (from 'The Art of Electronics 3rd Edition') to measure the noise of some fast low noise npn I got. 126151 But it is not really well described in the book. I don't get the use of the "pre-insertion" and R4. Also I don't understand the use of the small resistors R2 and R3
Hi I have to measure noise figure in a circuit that I have attached its picture. Also I should check the isolation between 1. antenna ports and and LNA. I'm not familiar with ADS. I would appreciate if somebody help me with these two cases. Thanks in advance Parisa 124874
How much current does it takes to charge your battery? does your diode takes that into consideration? maybe you just need a bigger diode... anyway, I don't think you should have any problem using a relay, maybe add a snubber and a hysteresis/voltage level driver to minimize switching noise...
It sounds as though the device is plagued by false triggers. This shows a common method to stabilize a sensitive input. (Of course it is only supposition on my part that this could be your My above post is
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? Pls show your problem with photo of layout and scope trace. ( assuming 2.5 or 3.5 mm stereo with Gnd switch )1
I agree with Klaus, without a schematic and layout we can only guess. I have done similar designs with high power switch mode power supplies and similar circuits where you get very high switching currents. There will be two main methods of noise coupling inductive and capacitive... The inductive is combatted by trying to avoid any sensitive (...)
Hi there I have several questions when I use the the PSS+pnoise to simulate the noise of the SC circuits as follows: 119004 119005 1) Ron is the Equivalent resistance of the switch,the noise of Fig.1 does not change with with Ron,but the noise of Fig.2 has relationship with Ro
Flicker noise is infinite at DC. Speaking properly, what tends to infinity in the flicker noise model is its power spectral density. If I pass flicker noise through an on/off switch with switching frequency w, what the output spectrum would be? Would the spectrum be infinite at w, 3*w, 5*w?etc? It doe
Hai , i was making an A/V selector switch that will be controlled my microcontroller. I will be using SPDT relays each for Video, left ,and right. The NO and NC contact of relay will go to 2 different sources. So my question is will this configuration give out any sort of noise (because inside the relay the contacts might be
Don't use ceramic caps, they have a memory effect. Use a small film cap for the S&H cap. You can work out the RpC leakage rate for sag and RsC capture rate for sample and choose values according to speeds, noise and rates required. Analog CMOS MUX switches are preferred with low glitch feedthru
It is not a good idea to test the switch mode power supplies on bread board, unless you are expert in power electronics. High frequency switching currents creates lot of noise and spikes in ground. PCB with good layout is recommended.
Microprofessor, ha, ha, that is a good joke.:lol: A switch contacts bounce when the pushbutton is activated which results in many pulses fed to the digital input that counts all of them. The capacitor is normally charged and is discharged very quickly on the first contacts closure and during the bounces its slow charging by the 10k resistor
Hello. I have a switch which pulls down (to ground) a pin of a PIC18F65K22 Micro to give a logic low. If the switch is open then the pin is pulled up to the 5V rail via a 47K resistor. Do you think I need a 10n (or thereabouts) capacitor connected to the pin to reduce noise at the pin? When pulled high, and without such a capacitor, do (...)
I would not recommend the usage of a 555 IC, because to charge a capacitor in exactly 1 hour is almost impossible because of temperature, component tolerances and ambient noise. I recommend the usage of a 'high' frequency clock and then to divide it. Another option is to use a MCU.
I see contradicting aspects that could reason the assignment to one or the other supply node. - bus operation causes noise injection to the supply - power supply noise shows a certain feedthrough to analog switch nodes Unless the analog circuit connected to the switch involves ultra low signal levels, digital supply (...)
could you be overloading the power supply or getting noise on the power lines when the motors switch on?
Hi, It depend on the distance of the sensors. Maybe a digital bus system has benefits. But surely it is more complex than with the multiplexers. Also you need to calculate expected sample rate, low pass filters (noise, anti aliasing...), and settling time when you switch from one signal to the other. To ease the design you can use 4 pieces 16:1
hey guys, I'm an undergrad in software engineering and I'm doing my final year project. I'm trying to power up a monitor and a Beaglebone Black from the car. I have used a 100W Inverter for the monitor and a LM2596 regulator for the BBB. And the LM2596 is a switch mode power regulator. Check diagram. 104981 But I d
Hi, I have three things connected to AC power in my room, a fluorescent lamp , my PC, and this circuit connected to CFL bulb. The strange thing is when i switch on the fluorescent lamp the speakers of the PC produce a popping sound,and if the PC was a sleep it turns on, and the CFL bulb
102347Hi, I am using a microcontroller to drive some relays that drive contactors. My board is powered by the 208Vac through transformer then through bridge then to LM2596 simple switcher which gives a 5.0V output. Then that 5.0V is sent through a LM3940 to generate 3.3V output needed for other chips. There is another con
Does your system switch off current through a coil by making it see high impedance suddenly? It needs to continue to generate current. High voltage spikes can result. These are probably the noise on your waveform. It might be solved by a snubber network across your H-bridge. Possible a resistor and capacitor in series.
I deleted this since Venkadesh_M pointed out in #16 & #18 that the illegal condition can't happen the way the switch is wired up in this application. The only thing that can cause unexplained multiple output pulses is if noise is present on the inputs or power supply pins.
1. these resistors are just for safety, they are not really required. 2. these components just suppress any sparking or noise as the pot is rotated. 3. Its to pull the input down to earth in the absense of pulses. 4. This pin needs a 1 on it for the IC to work, the caps just suppress any negative going spikes that migh switch the IC off. 5.
944809448194482 Hi, I was playing around with some variable frequency audio signal. The signal was fed into a reed relay before being fed into a passive low pass filter (1~5khz). The thing is, the signal seems to be "pre-filtered" by the relay as i got quite a clean 1khz
Possible mic sense the dc-fan noise?
Is it true that LED car indicator lights (flashers) have to be done with linear LED drivers because switch mode LED drivers cause too much ringing on the power wires feeding the indicator lights.?. It is quite likely PWM would radiate a lot of noise in the AM band so filtering would absolutely necessary.
Not exactly (there is no "noise level" as you call it-I don't know what that means). The amount of hysteresis is a function of the ratio of R4/R3. If R4 was just a wire, it would never work, as the input voltage would have to go higher than 5V when the output is 5V, but you can't drive the input much higher than the supply without damaging the
Hi, Which one is better? is The diode in second circuit effect to reduce noise? and the switch is connected with 20 meter wire. 89284
WHen you input switch operates it bounces and the TTL input is floating at threshold of 1.3V. Any rapid noise on this input will cause shoot-thru shorting of the drivers. Any change in directions will also cause motor/generator back EMF to dump into drivers. Therefore use 4K7 to 10K pullup on all TTL inputs at switches and 0.1uF to ground.
how to simulate the noise of this circuit as attached picture88658
Guys need your suggestions: I have an application where I have to switch power to load ON/OFF with a Soft Start and Soft Stop. At 24VDC the load current is around 9A. For Power source I have a SMPS with 24V output with adequate current supplying capacity. Now I have to choose the switching device. Since the load is inductive (A PMDC motor), I am
If you're measuring noise at ground, what is your reference? Are you measuring the noise along the ground line, whereas one point (eg battery -ve) is the reference?
your problem is the noise. The switching triggers a noise which resets the controller. How does the isolator serve its purpose if both i/p and o/p are having the same Ground? you could first switch a smaller relay (SPST) which in turns drive this solenoid relay.
Hi~ I simulate noise of a fully differential OPA switch cap structure using spectre Pnoise . I have some problems First i use PSS and Pnoise analysis , then i want to see input referred noise , and it is impractical small , just about 20nV/Hz (better than IEEE papers so imust some where wrong.......) (...)
Simplest way is to touch each component with tweezers and see if it affects the noise. Normally I assume noise is due to inductors. Capacitors usually only make noise if they have a poor dielectric (Y5, Z5, etc).
is this for data receiver margin testing or loop stability margin test or noise test?? an All Pass Filter Design, microstrip, stripline or coax? switch depends on test?? Can you use hot carrier schottky diodes?
e switch conductance versus input signal Vin. ? crosstalk pn Vref. from digital noise of SAR? Where does it come from? I think you need a design that has ON-resistance that is nearly constant. How I dont know.
I designed a VCO which some part of it is switched by a periodic source. The switch frequency is 1/100 of VCO frequency. I want to know how can I simulate the VCO phase noise with pss and pnoise analysis in Cadence? I want to know the required setting in Cadence. Thank you in advance.
Your resistors are quite high - high impedance is more prone to noise. Try 10K. The other thing is your power supply - how 'clean' is it? I'm not familiar with the Arduino, but when I do ADC on PIC's the power supply, and especially the separate analogue supply input when available needs to be very clean. With just a cheap, switch-mode PSU as the
That looks like very HF noise and it's not ringing per se because it doesn't decay. The edge overshoot may just be an artifact of the output switch kicking the ground that you're referred to. Be aware that adding capacitance (probe) to the SW node will add to the observed noise / overshoot as-displayed. Use a series resistor with your (...)
i think your design is more appropriate for low voltage application. but i see you are using 600V mosfet, so i think probably you have higher DC bus. with higher DC bus, your switching will be susceptable to noise due to the floating reference of your upper switch. need to take better care of isolation. check TI chick TD350 and use a (...)
hi what is menat for noise margin settle time (rise and fall)and switch timeIrise and fall) please explain this with simple example
Another point of choice could be the kT/C noise if it is of concern...
How to calculate the thermal noise from the switch cap array of a SAR ADC? Thanks
Greetings sir, i have designed a dual band LNA in ADS 2009 for two operating frequencies 2.4GHz and 5.4GHz... i used an SPDT switch to switch between the matching circuit for two different frequencies... i took the SPDT,static model of switch in the schematic design... now i want to fabricate my design and i am in need of an SPDT (...)
You cannot just ask for values! Run simulations first. You know fs, power supply, and input range, then you have do run sims to make sure the 1st opamp amplify the input to the desired range and filter the outofband noise. Then decide the switch and the cap to make sure it settles in less than half the clock period. Then the bandwidth and accuracy