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Current Feedback Compensation

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24 Threads found on edaboard.com: Current Feedback Compensation
witch is a better solution 1 , 2 or 3 of course 2 may not work another question is that T2 in circuit1 are act as base current source or
As a general concept, you want to configure the internal phototransistor to respond to the internal led, so that it delivers the correct volt level to the feedback pin. You must create the proper amount of current going through the led. If output voltage changes, then it must cause led brightness to change. In regard to the phototransistor, you i
Hello, Why is the current ringing at several MHz in the resistor (R7) connected to the LTC6101 current monitor? This doesn't happen in the similarly connected LTC6102 circuit (as shown). Also, in spite of the ringing, the actual output of the LTC6101 circuit seems OK. Please find LTspice simulation and schematic attached.
Do you agree with the following ?rules? (A to D) on the checking of type 2 compensator pole and zero positions? This is with regard to a CCM, current mode flyback with a type 2 feedback compensation network..That is, making sure it is not going to be unstable.. ?The Type 2 compensator zero MUST BE at (or very near) the same freq
Hello, On pages 212 to 217 of ?Power supply cookbook? by Brown, it goes through a type 2 error amplifier feedback compensation scheme for a CCM flyback in current mode. It discusses the placement of the error amplifier's poles and zero, but does not do this with respect to the power stage RHPZ. Why is no mention made of the RHPZ? Surely (...)
HI, I used the attached circuit to drive led about 10A. if mosfet operate in saturation region, the dissipation power of mosfet is large. so is it possible that mosfet operate in triode region in vccs. and what is differences between them, for example In triode region will cause the current stability problem or mosfet broken.109282
When You designing two stage ota, the first of all You need to add a compensation network (e.g. Miller cap with nulling resistor or used a cascode compensation). Your amplifier is unbalanced - output transistor should be matched with first stage current mirror load. In addition the phase margin and GBW depends to feedback (...)
Although the feedback compensation can be optimized, you'll should be aware of a transient output response when switching the load. My main concern would be that voltage control of multiple LEDs is far from optimal control. I would go for individual current amplifiers and all signal switching on the amplifier input side.
According to the datasheet, the device is operating in current mode. This means, there's no way to set a constant duty cycle.
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.
I am refering to the feedback resistance when using the amplifier as an inverting amplifier. It's setting the current gain of the I/V converter (or transconductance amplifier), the value depends on your application requirements. In case of CA3130, you should consider the compensation capacitor required for unity gain stability. A
Audible noise usually indicates unstable feedback loop, or e.g. subharmonic frequencies that can occur in a current mode converter without suitable slope compensation.
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
C9, R6 and R1 are providing a loop gain compensation. They are necessary for stable operation. R2 causes a bias current. It may improve the large signal behaviour according to the TOP204 properties. Analysis of TL431 circuits has been discussed in previous edaboard threads, if I remember right. The part I don't understand is - why is the
You would expect the dropout to be minimum when the pass transistor is fully turned on. Therefore, the dropout is simply iLoad * Rds(on). You will have to do stability analysis at maximum current load according to specs. That's where compensation is usually required.
Hi, I tried to make a constant current LED driver using UC3845 to which vtg feedback is given as the drop accross sense resistor. Even though it is working the loop seems not stable. i am seeing a ringing which mayrequired slope compensation. Any body plse help me how to solve this
No the HV9910B operates in open loop current mode control.There is no closed voltage loop,no voltage feedback,So no voltage loop compensation need. But if HV9910B is in Peak current mode control,the inner slope-cpmpensation must add when duty>50% in CCM. PFM SMPS need no loop co
If you don't two scenarios are possible: 1. the loop will oscillate and your output voltage will have large low-frequency ripple, most likely exceeding the specs. 2. The loop may be overcompensated and in that case very slow to respond to sudden changes in output current demand (poor transient response performance). The output voltage will "di
You need to build a current mode behavior model first.
well depends a little bit - I would look at the whole thing as a two-stage opamp with miller compensation (forget about the nmos h-bridge and dthe common-mode-feedback-resistors) ... so now you have to solve the problem how to design a two-stage opamp - and you should think first about the point imo - where there nondominant pole in the left han