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149 Threads found on Feedback Compensation
Hi my friends Can i use formulas of "AN-1162" for calculate current-mode compensation network? if no, Can you give me a practical reference like AN1162 to design stable feedback loop for current-mode? I use UC3845 and TSM101A for design constant current power supply.
You didn't report your exact test circuit. I presume you are injecting the AC voltage at the reference node. I don't understand why you are interested in potentiostat behavior at 100kHz or above. Which real world problem is covered by it? feedback loops involving multiple OPs generally require frequency compensation. You possibly get more se
Dear Okhey Hi What resistor you are referring to ? can you show me your schematic ? About op amp : how much is the frequency of operation ? Best Wishes Goldsmith I am refering to the feedback resistance when using the amplifier as an inverting amplifier. The frequency of operation is about 100 Hz.
To me this looks simply like "feedforward compensation" in the feedback ladder. You see it often enough in regulators. Also called "Type III" compensation. There should be no DC term, then your concerns about temperature drift (from that) go away. PSRR should be improved at medium frequencies where you are making better use of amplifier (...)
From this suggested working model design , I would simply follow their lead and choose a single pole RC feedback at just above the operating frequency so phase shift is < 45deg and adequate harmonic attenuation with the feedback voltage bias ratio,N set to Vout= N * 1.25V They run at 1.5Mhz here.
when i use a resistive feedback ota as a TIA, i find that the feedback resistor leads to startup problem. the ota is a 2nd-order opamp with miller compensation. how to solve the startup problem?
This completely depends on the specific error amplifier circuit. In general there is no buffer amp between the output divider and the error amplifier network, in which case the impedance of the output divider will need to be taken into account in the error amp transfer function, so then the above statement is correct. Personally I like to put a b
Thanks for the help! I'll compensate it with Type II compensation network. However I have one more question. The attached figure shows the bode plot for the same converter in DCM. However I've changed the small signal feedback gain a bit. Green line corresponds to k=0.1; blue line to k=0.15 and red on to k=0.2. Simulations (using ideal com
hello can anyone suggest me how to control quasi resonant buck. I had designed the power stage for 2MHz switching operation (resonant freq is 2.7 MHz). In my feedback loop i am using VCO and Eamp with type 3 compensation. I had reffered ON semiconductors appl.nte for the compensator design. The problem is my output is settling at required voltag
Miller-opamp isn't a clear technical term in my view, rather a sloppy phrase. I assume, that you mean a miller compensated two-stage OP? 1) The feedback doesn't affect the compensation directly. For the analysis, you should distinguish between amplifier open loop gain and closed loop gain. The output load, e.g. the feedback resistor ho
sir i have designed a simple Boost converter 12v to 24V, with feedback control using uc3845, it works great the Inductor switching frequency is 55Khz, the problem is that it makes an audiable Noise which varies according to the load like SSsssssssssTTTttttttTTTTttssssssss ..
Hello, Offline, switch-mode LED drivers that exist *inside* 4 foot LED light tubes, suffer heat, and therefore cannot use electrolytic capacitors........... -therefore, small-Faradic-value value film and ceramic caps have to be used at the input and output.... ..this makes feedback compensation and stability very challenging.....what is u
It obviously forms a feedback structure. A risk of instability is particularly brought up, if the compensation crosses multiple stages, involving additional poles. This is the case in your design.
there is a fair bit of learning involved for someone to calculate the feedback components for stable, fast operation, each situation is different - your question is too open ended.
is this an op-amp differential amp ? if so the gain, unity or otherwise is selected by choosing feedback resistor values. some have external compensation capacitor terminals. Otherwise additional to the feedback resistor, you can in parallel add an RC to effect the gain bandwidth. All within the capabilities of the device itself though - its (...)
Lower feedback network impedance will move one of the poles to the right, increasing bandwidth some if that is a limiting factor (I would suspect not, if you are talking tens of kOhm and tens of pF). Shunting that upper resistor with a small C and/or RC series, gives you feedforward compensation and tweaking that can get you a lot of improvement
You have used high impedance feedback and twin T notch filtering using low slewrate op amps uA741 . The input bias current in these are high .and compensation current reqts. are larger which loads the filters . Pl go for high slew rate OPA like TL084 which have FET input stages and very high slew rates
A feedback amplifier and compensation circuit involving pins 1,2 and 9 should be supplemented. The 230 VAC output needs to be rectified for the feedback.
Im measure adc pin with a multimeter but it gives good values. So the problem is either with your code, or the analog input pin is damaged. I tried feedback capacitance but nothing changed. Yes, an oscillating OP output should still give an ADC signal. Simply keep in mind, that a compensation cap will be necessary f
Dear Collegue, I have a Photodiode that produce a ripetitive (but don't periodic) signal with an amplitude of any millivolts. At this true signal there is an offset that canghe in the time with an amplitude around a volt. I have supposed to reduce dinamically this offset with a circuit composed of an Programmable Gain Amplifier that amplif