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298 Threads found on Amplifier Phase
Hi, First: Filter away all unwanted frequencies. Then: decide if you have a fixed and known phase angle between your reference signal and the input signal. If yes, then you just need a controlled rectifier. If no, then you need a complete lock in amplifier. In another thread I posted and discussed a curcuit. Klaus
I think that is a stability problem because there is feedback circuit from output to OPAMP and phase shift is not clear. As KlausST said, a AF Power amplifier can be used, they are stable.
The amplifier's phase and gain plot: 136626 When gain=0dB, the phase marge=72, which is stable for the unit gain bandwidth 22.7MHz. However, the phase changes a lot within the unit gain bandwidth, like a sine waveform. In this case, is it acceptable for the phase not monotonically decreasing? Thanks.
Hi, I want to know the differences between low noise and low phase noise amplifier. Thanks in advance
Hi, This is the picture of a mini magnetic amplifier (called ferristor). If one would want to build the ferristor, how he should wind the left hand side windings? My guess is that the left winding, must be two with different phase (wind opposite) so that they can cancel the transformer action from the output winding. So how to wind them? A guess
The PMOSFET is wrongly connected in your schematic. You should also consider that the MOSFET booster circuit is adding gain and reducing phase margin so that the amplifier needs additional frequency compensation to achieve stability.
Load Pull can be used, no doubt. If you consider the oscillator as an Power amplifier, the principal is almost same,so max. power at the right impedance. But.. Load Impedance is also quite deterministic on other specifications of the oscillator such as phase Noise,Drift and Pulling effect.If you would obtain max. power from the oscillator, you may
You see loop gain indicated in an amplifier open loop gain diagram. The point "way down" is unity gain frequency. Feedback factor < 1 is the missing link. Read the text completely beyond the quoted part.
A PI error amplifier would be my first guess. You didn't tell about the phase shifter range. Generally, an additional comparator for positive or negative phase difference and phase reversal switch are required to push the phase difference to the right part of the detector curve.
For an error amplifier, the stability is defined based on the response of the amplifier for a range of sine wave frequencies. or something like that... Stability can be determined by analyzing the loop gain magnitude and phase versus frequency. For simple cases, the phase margin can be used as stability criterion. The (...)
Hi, Read about "lock in amplifier" (LIA). It is a solution to measure amplitude and phase angle (0..360). The output is low pass filtered and therefore you may see it as DC. = easy to read with an ADC. You need at least two bipolar ADC inputs per channel. *** The XOR solution is easy. You need reliable zero cross signals from a clean sine wave.
A thin wire has series resistance and series inductance that you do not want in a high current power supply wire to an audio amplifier.
to make analog amplifer, I connect negative feedback and phase shift of amplifier should be below 180 when amp gain is unity gain because if not, output of amp is larger more and more or oscillated. But when that conditions are satisfied, how can i prove that amplifier is not oscillated? for example, at specific frequency, when gain (...)
Hello all, I have a BPSK/QPSK type signal from a transmitter. Carrier frequency is 400 MHz and data rate is 1 Mbps. The BPSK/QPSK signal is to be transmitted to a remote receiver. What type of power amplifier should I use as the output stage?
Hi, Lately I'm reading a book on (audio) amplifier design. I have some questions about the Miller capacitor in the attached schematic. From this audio book I read: "The global (overall) feedback factor at low frequencies is sufficient to linearise the VAS, while at high frequencies shunt negative feedback through Cdom conveniently takes ove
Hello I have a question about a feedback resistor value. To bias an input of an amplifier, we can use a feedback resistor from output to input. Normally we use a high resistance, but there may be problems. 1) amplifier input impedance If the feedback impedance is higher than the input impedance of the amplifier, input currents (...)
Hi guys, I'm current working on electret microphone amplifier. I found two circuits from other thread that are almost similar but with some differences as highlighted in the attached figure. Could anybody explain the differences referring to the figure? Awaiting your valuable response. Thanks. 125315
I want to design a CMOS analog frontend for OPTICAl BIOSENSORS , I want to design it using transimpedance amplifier.... but I didnt find the specifications required for the amplifier i.e: 1)what are the ex of optical biosensor ? and 2) what are their characteristics ? like Gain, Bandwidth , phase Margin , (...)
You bought a Chinese amplifier. We do not know if the IC is a REAL TDA7297 or a poor Chinese copy. Its datasheet says it is made for use in a TV or a portable radio, not in a car. Its speaker is supposed to be 8 ohms, a 4 ohms speaker which is common in cars might burn out the amplifier. You need a car stereo FM transmitter that is commonly sold t
Hello,I would like to control a three phase motor respecting phase order,could you advise on how I can do it,for zero crossing detection I used an operational amplifier as a comparator for detecting the zero crossing level,and I also I want to start from a low speed which could be increased with a push button,I planned to use the TRIAC (...)