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# Positive Pole

26 Threads found on edaboard.com: Positive Pole

## Is there a negative miller effect?

Yes - such a capacitor between C and E in common-B configuration provides positive feedback and, thus, increases the input impedance for rising frequencies. This can be also described by the term "invers (negative) MILLER effect". However, at the same time, the gain decreases (C parallel to Rc). Why do you expect an RHP pole? [SIZE

## 3 order loop filter in PLL

1 st order are inherently stable but noisy 2nd order are less noisy and C2/C1 ratio affects pole position 3rd order are inherently unstable with >180 deg phase shift and negative feedback becomes positive feedback. Rule of Thumb ratios help provide LPF additional rolloff using lag-lead filters to give phase margin at unity gain and may have

## pole is where the transfer function tends to infinite but bode plot magnitude respons

As I recall the negative feedback loop may have zeros, but the transfer function of P(s)/Q(s) for the positive input is often 1/(1+H(s)) thus the overall gain never reaches zero unless H(s) =-1

## Question of one interview question about positive feedback

Hi guys, I have a problem about the stability of positive feedback. Let's say for a opam, it has 3 poles (LHP) at DC and 2 zeros (LHP) at wz. Then at DC, its phase shift is -270 degree , and at wz, its phase shift is -180 degree. At wz, its gain is 4. Then we connect the opam in a unity gain negative feedback structure. The phase margin of

## RF circuit Stability analysis by Transfer function

If Real(s1) and Real (s2) is positive, the circuit will absolutely be unstable regarding to Hurwitz criteria.

## phase margin issue with a positive feedback in current mirror OTA

please leave this figure it is not that clear, refer to the first one of my post with the separated results , the curve with the DC gain of 81 is the circuit with the positive feedback the second graph with the DC gain of 74 is without the positive feedback I dont know what you mean to say by my self, I am using mentor gr

## dominant pole and stability

You'll determine stability by analyzing the loop gain magnitude and phase characteristic. For the simple case of monotone magnitude characteristic, a positive phase margin implies stability. A considerably larger phase margin will be required for acceptable time domain behaviour, however. Strictly speaking, an OP with only two poles and real fee

## Can Create an Oscillator with Negative Feedback

If you have a transistor with components connected from its collector circuit to its base circuit, its negative feedback, because when th collector signal goes positive, the base signal is going negative. If however you change the components so they introduce greater then 180 degrees phase shift and the transistor has a gain greater then 1. The cir

## Identify SOT-23 SMD that should work like a bidirectional switch?

Yes, I mean the Vcc, the + pole of the battery, call it how you want! Vss is how microchip calls it in the datasheets, that's why I used it like this. I never saw the positive supply node named Vss in a datasheet. If pin 2 is the positive supply node and pin 1 more negative tahn pin 2, you'll expect a PMOS FET like Si2323.

## What is the difference in having different real parts of complex frequency pole?

What is the inverse laplace transform of 1/(s+a)? What do you think happens when a is positive?

## Variable current source with grounded load

Grounded load only means the the load is connected one end to a ground .. In this case the current source sources current from the positive pole to negative pole (ground) through a load .. If you use current source a current limiting resistor is not required .. See: A Constant Current Source

## What is the significance of negative Q factor in a second-order low-pass filter?

That's not possible! Q factor by definition is always is positive. Check for calculation error.

## all pass filter realization

Thanks, flatulent. I want to realize a rising phase vs frequency, so it need a positive pole, and negative zero. But in many paper and book, there are a negative pole and positive zero.

## How to properly hook up a Full Wave Rectifier?

There no positive pole or negative pole concept in the alternative current, since it is continuously changing. It doesn't matter how you plug your AC since both poles will be having the same function. In the other hand, in DC DOES matter the polarization, since it is a constant voltage. From the + pin, you will have (...)

## why a peak at the end of freq respondence curve

It means you have peaking caused by a conjugated pole pair around 105 MHz. This pair is probably unwanted and can be caused by a feedforward path or positive feedback at that frequency. If you used feedback, is your phase margin large enough? You might be close to instability at 105MHz.

## effect of addition of poles and zeroes

poles and zeroes introduce phase shift frequency dependant. So at some frequencies the negative feedback can turn to positive feedback

what you see are more poles at f=1e8 . Each pole adds phase shift, but phase shift larger than minus 180 degrees is subtracted from plus 180 degrees (kinda fuzzy explanation). Basically what you are seeing is that the phase shift is clipping. Also the magnitude shows a positive peek as well again, this indicates some zeros at that point. Hope

## Nature of roots of a cubic equation

I have derived a transfer function containing 3 poles. All the coefficients are positive but from matlab analysis, there is one LHP real pole and a pair of RHP complex poles. Previously, I have a misconception that a cubic equation having all +ve coeff will yield all poles in the LHP. Could some mathematics (...)

## SIMPLE QUESTION ON b+

If I am not wrong, I read that the B+ comes from the Battery positive connector/pole used in old vacuum tubes/valve operated equipment (radios).

## zeros in transfert function

Dear All, why a positive zeros in a transfer function creates negative phase shift (just as a pole) ? Thanks for answering.