Search Engine

Operation Amplifier

Add Question

227 Threads found on Operation Amplifier
The first solution should normally work but I guess the internal diode-if it really exist-of the MOS disturbs the operation.You'd better perhaps use "low power switching act MOS" instead ??
Dear All, I have seen some papers on power amplifier design. They are biasing the transistor near their peak ft and saying that transistor is biased near class A operation region. I did not understand conceptually that if we bias the transistor near their peak ft then, we are in class A region. How is the the different biasing classes related
Class-E amplifiers are generally used for high efficiency, not only pulsed mode operation.But their design and implementation is quite difficult, needs quite deep RF design and optimization knowledge and technique.They are also quite dirty amplifiers in term of harmonic content.Class-E amplifier can also be used no doubt but (...)
Are there any more specifications? What is the minimum load value allowed on the output? Are you limited to one active device per stage? What is the maximum output swing expected? Maximum output distortion allowed? Frequency bandwidth of operation? - - - Updated - - - It would be much easier if
Hi, I am trying to understand about the Mosfet operation. It would be great if someone could help me get answers to these questions - 1. What happens to an AC signal (DC+ small AC signal) if it is applied to the gate of a MOS which is biased in Linear mode. In the saturation mode, the output at the drain/source can be found using the small si
Your opamp is very simple and is missing a voltage gain stage so its voltage gain will be low. Its supply voltage and operating current are extremely low. Its bandwidth and slew rate are very high for an opamp. The resistor values must be fairly low for operation at the VHF frequencies due to stray capacitance, but the resistor values must be very
Yes, and the Output can be Either Stepped UP or Down in Voltage. You could also have Multiple Output Windings. Your Biggest Problem is Making a SUITABLE Ferrite Core Transformer for the Frequency of operation. Typically it should be wound with LITZ Wire, to better handle the High Frequencies involved.
I think is not justified to design a high-efficiency Class-E power amplifier at +20dBm, because at this relative low output power the transistor cannot behave as a perfect switch, as the Class-E requires. Especially when use a transistor that was designed and manufactured as an LNA, which theoretically should work in pure Class-A operation.
BJT are fast if not driven into saturation. In addition MOSFET gate driver must provide low impedance push-pull operation, particularly fast gate discharge. That's impossible with your single transistor high side driver circuit. Just helpless.
Hi all, I have to design an opamp in 28 nm. So, I used Phillip Allen book as an example. However, then I was looking for Kn or Va - I found some posts (on this forum) like: don't carry about Kn, due to short channel effect - it's relevant. or Va (early voltage) is only for old technologies, not it isn't suitable for design. Sooo, what sh
I'm now make a board to produce a sub-nanosecond pulse using avalanche transistor. And I made it successfully. I'm quite sure that the waveform doesn't show avalanche breakdown. just linear amplifier operation.
but when input signal is 0V then output is 2.5V - it should be 0V. The requirement seems to contradict the previously specified +/-2.5 to 0..5V mapping. Would you mind to clarify the intended amplifier operation as an input/output voltage table. You want Vout = 0 for Vin = 0. What's the expected output for Vin = -2.5 and Vin =
ok, well here is the rendition of that diode that I have seen used, it means that the error amplifier output voltage doesn't have to transition so far in order to "brake" the smps at start yes it helps to reduce overshoot of vout at startup. -its ltspice simulation and pdf - - - Updated - - - I
In some respects your LC filter is like driving a woofer from a class D amplifier. Try the online calculators for this type of second order filter. Input your load impedance. For cutoff frequency choose 70-90 Hz, because if you choose 50 Hz it will attenuate your waveform and you don't want that. In other respects your operation is similar to a bu
1. I think you mix up the overdrive voltage Vod with the drain-source voltage Vds. The usual definition of Vod is Vgs = Vth + Vod (... where Vod would be negative for subthreshold operation), whereas in your definition the overdrive voltage of th
operation is not too different from a sine-PWM inverter. You start with a sawtooth wave at the input of an op amp. At the other input you apply audio. The modulating effect creates pulses of varying width. You need two PWM generators. One applies current through the load in one direction, one applies current in the other direction. This is a simp
A transistor in common-base operation can do the Bias adjustment is critical. Supply voltage must not change. With effort you can get near linear response. Output will be close to 0V when you input 0 mA signal.
I know for transformer coupled circuits when current becomes zero the back emf acts and the collector to emitter voltage is increased.But why does it becomes exactly 2Vcc.I am actually having trouble figuring out the value of back emf offered 119915
Your latest simulation show the amplifier in overload, input differential voltage is much to high, in so far the results are meaningless for regular operation. Please repeat with reasonable parameters, resulting in non-distorted output.
Set the inputs to A-B, this will get your 9 bits to work on the difference of the two signals. Not sure about. With most DSO that I know, A-B is a digital operation rather than utilizing an analog differential amplifier.
Hello, I am using ADS to design a symmetrical Doherty amplifier. I am using Quorvo's (Triquint) device: T1G6001528-Q3. I know how to bias the transistor for class AB and class C operation so that I have a Carrier amplifier and Peaking amplifier. The next step is to find my optimum load impedance for both transistors (...)
I am using GaAsFET amplifier FLC107 from Sumitomo,it requires -ve gate bias and +very drain bias voltages for its operation. By mistake my technician reversed the gate and drain wires,i. e drain received -ve and gate received +ve DC supply.-5v and +2v to be specific. I thought device might have been damaged by reversing the polarities,but when
Hi friends, I'm confused about operation of an RF amplifier(MMIC or single transistor) biased through an RF choke. I know the two basic functions of the RF chokes. An appropriately chosen RF choke helps DC biasing by filtering the supply and it also prevents the RF signal from leaking into the supply which causes reduction in the gain. It is neces
Read margin is defined as the bit line differential when you turn on the sense amplifier. During a read operation the bit lines the bit line with 0 data will discharge a differential is created between bitline and bitline_bar. Once it reaches a value where you have sufficient difference between the two , the sense amplifier is fired
Sorry, I meant 0dB. I have to ensure that it is under -15dB at my point of operation (1.575GHz)? But what is concerning me, is that around 900MHz my S11 is greater that 0 dB.. I changed the polarization, chosen 20mA (less gain) at I get the same situation.. Any ideas? You amplifier is not stable therefore S11>1 in
In operation amplifier datasheet, common mode voltage range is often used as a synonym for the absolute input voltage range, considering the only small differential voltage amount. But this assumption isn't correct for instrumentation or difference amplifiers with low finite gain. In LT1990 datasheet, the term common mode voltage is used (...)
I would go for the current source. An AC voltage source probably shorts the amplifier output during operation point calculation and causes a wrong DC bias point for the succeeding small signal analysis. Checking the bias point is useful anyway.
It should be chosen to achieve saturated operation of both M11 and M12.
Linear operation is possible if you set Vgg to 3.5V, maybe even 4V for very linear amplification. And because 64QAM has about 7dB peak-to-average (and 16QAM about 4dB) might need to back-off few dB's the output power, to get minimum signal distortions and lowest ACPR.
Hello experts! What is 74HCT244 (Octal buffer/line driver)? What does it do? How does it work? How does it produce its output? Thank you
I guess 2V exess will not harm device.5V OPs have usually a maximum functional supply voltage specification of 5.5 V. Between this voltage and maximum rating (the permanent damage limit), correct operation isn't guaranteed. Regarding output swing with 50 ohm load, did you review the output current specification in the datasheet?
Hello everyone, Is there a necessity of using a sense amplifier while reading from SRAM?
Hi Any one know how to do transfer function Vg(s)/Voe(s) of this op amp without drawning small signal. I know some one can do this quick but I do not know the trick.
Hi, I am working on the OFDM transmitter system. I have observed that the carrier signal peak power level is -3dBm whereas the peak power level of the OFDM (256 sub carriers) signal observed is -42dBm. Also the channel power measured is -42dBm . Frequency of operation is 2.45GHz. Power amplifier used is MMZ25332BT1. I would like to know if th
2 reasons may contribute to the gain reduction: 1. the CMFB inputs' impedance loads the FD amplifier outputs 2. the CMFB control mechanism might change the operation point of the amplifier into an awkward region
There are several circuit faults, LO2 and HO2 interchanged, both HS pins that are necessary for bootstrap operation unconnected. So at present, the circuit can't work. But convergence problems aren't unlikely with MOSFET switching circuits, thorough tuning of transient analysis parameters may be required to get the circuit work after correcting
This is a nice handbook if you want to read about power supply operation Linear & Switching Voltage Regulator Handbook - ON Semiconductors
The LDMOS transistors BLS6G2731-6G or BLS6G2735L-30 from NXP are specified for Class-AB pulsed RF operation in 2.7GHz - 3.1GHz range. Most probably if you back-off the output power (and losing efficiency) you can use the transistors for a Class-A PA design.
I'm having trouble understanding the purpose of precharging the BLs during a read operation of a traditional SRAM. Is it because after a previous operation you want a common starting point (both bit lines being 1) so the sense amplifier can begin to sense the change in the BLs? Thanks everyone. I love this community.
Unless you are not going to put the cascode PA working in E Class or something similar (switch operation) your circuit would have less PAE than any other single transistor amplifier. For maximum PAE is not enough providing the right bias to the amplifier, but also the amplifier must get proper load resistance, which cascode (...)
and another from referance to "+" terminal Why? Sounds definitely wrong. Generally speaking, you would to test the current sense operation under well defined conditions first. ("calibrate" the sense amplifier) - no output without a load - correct output with defined resistive load - correct output with defined capacitive load
Sir, I am beginner for design of power amplifier in ADS2009. I have noticed in the ADS 2009 Design Guide > Power amplifier Examples - By Class Of operation > class B > Load Pull -PAE,Output Power Contours, they have taken the GaAsFET FET1 transistor nonlinear model and also shown the STATZ_Model. I am having the following doubts (...)
Hi, I am looking for an amplifier (preferably a MMIC) which would meet the following specs and would be grateful for any recommendations: Band of operation: 10MHz to 400MHz. Extremely linear, i.e. IP2 > 70dBm, IP3 > 40dBm Gain: Nominal 16dB P1dB: Around 22dBm Low noise figure: < 2dB preferable The minicircuits PHA-11+ (Dual matched E-P
The effects you are describing apply more or less to any amplifier in large signal operation. That's why load-pulling is a straightforward way to determine the output impedance for a given operation point. Harmonic balancing should be a suitable analysis method, too. Optimum Load Impedance would frequently be different
Use an operational amplifier which can drive output linearly all the way fom 0V to +V supply(Vss to Vdd). Search for rail to rail output.
You need to know M1 input impedance for the given operation point and circuit. Unfortunately, it's affected by M1 load impedance. So you'll usually start with an estimated value and later adjust the matching networks. Then the matching network can be designed by different methods. Graphical design in Smith Chart is a common method, there are als
Why are you worrying about negative MOSFET drain current? It's just normal operation of the present circuit (due to parallel C).
Hi, Currently fast envelope tracking DC-DC converters used for envelope tracking applications use a combined parallel structure of switching and linear converter. The operation of combined structure is something like this: When the modulation envelope voltage increases, linear amplifier follows it. Output current sensing circuit senses an
Hi, I have been trying to understand how class-E amplifiers work. All the books/articles which i have read just give mathematical derivation of class-E. However, no where i have found an intuitive explanation of Class-E operation. Can somebody explain how class E amplifier works. regards
Please consider that RFID reader operation depends on load modulation, which involves the ability to read the RX signal while an unmodulated carrier is transmitted. Connecting external PAs between reader IC and "antenna" coil is possible under some restrictions, but must not disturb the RX operation. Don't know what you want to achieve, regular