Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Recent content by ivyahoney

  1. I

    asymmetric differential mosfet as input pairs to implement a comparator? hysteresis?

    Hi, Here is my question of a analog comparator with its input differential pair of different single width but of the same total width (different fingers). And there is no symmetry of the differential pair on the layout. so why does it happen? I am learning this circuit from an experienced...
  2. I

    Please help me solve this oscillating bandgap, thanks!

    I have checked the threshold voltage, and there seems no problem... I have changed another startup circuit. Please help me with this startup, will it be enough for this bandgap structure? 1 My amplifier is a two-stage amplifier with miller compensation, when I plot the loop gain and phase...
  3. I

    Please help me solve this oscillating bandgap, thanks!

    Hi, I am realizing a low voltage bandgap(shown as "sch.png"). I use a schmitt trigger to turn off the bandgap's start up circuit. The upper threshold voltage of the schmitt trigger is 500mv, and the lower threshold voltage is about 400mv. The output voltage of the bandgap circuit is designed as...
  4. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    Thanks, erikl. I sitll got some problems unsolved. 1. I still cann't fully undertand the distortion thing. Does the distortion means for the harmonic distrotion? "The cross-over distortion could be much smaller if we could keep the push and pull current above a certain minimum current Imin"...
  5. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    Hi, erikl, I have another question to ask, sorry to bother you. Why the "minimum current" is needed for the class AB output stages? As the paper said, the minimum current of the inactive transistor is needed to prevent signal distortion (prevent the inactive transistor from cut off), another...
  6. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    Ok, I will try again and find way out...Thanks! By the way, what is your opinion on this class ab control structure, compared to the traditional trans-linear loop? I have found in papers saying that the minimum supply voltage is decreased to vgs+2*vdsat (2*vgs+2*vdsat for the traditional one)...
  7. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    You mean that you have successfully achieved the max. current of 10mA by only consuming 10uA static current? That is great! What process do you use? 130nm process? As I mentioned before, I have used transistors which have long length because of low current bias, so how much bias current or...
  8. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    Yes, I have given 10nA as a bias current, and I want to see if it works. I have increased the ratios of between M100/M101 and M110/M111 to 32. I have followed your suggestion to set the vgsteff of both M110 and M111 equal. In queiscent state, assuming the current through M112 is 10nA, M115...
  9. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    Thanks for your reply! Q1---I am using transistors with their W<<L beacause of small current. Q2---There are some equations to calculate the max. current and min. current of the output stage. As the author said, M110 and M111 should have the same vgsteff (vgs-vth) in order to maintain the class...
  10. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    I want to realize this class ab circuit in 130nm process which is different from the paper, so I have to change the transistor's aspect ratio. And, the maximum length is 10um, so I have to series the transistors, I think. Actually, after I have simulated the circuit, I found that the maximum...
  11. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    It does have a large compensation capacitor, but I don't know why, here is what I think, The load capacitor is very large (~mF) to introduce the dominant pole. If I use compensation capacitor large enough, will it be possible to degrade the phase margin? Because, the larger the miller...
  12. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    First, erikl, thanks for your quick reply. Yes, the problem is to keep the static power consumption low in the meaning time to enlarge the dynamic output current. I got to know that TI has a gas sensor interface chip LMP91000. The opamp it utilized has the same minimum selector structure, and...
  13. I

    Want a discussion on Folded mesh biasing scheme-minimum selector class ab output

    Hello, all, I want to design an amplifier that can driving large capacitor load, in order of ~mF before the circuit is stable. I want to use this minimum selector output control circuit (shown in the attachement) to achieve the high dynamic output current, and in the same time keep the...
  14. I

    Anyone who have modeled a gas sensor with 3 electrodes? Please help!

    Hi, Recently, I want to design a potentiostat to maintain the difference voltage of gas sensor electrodes, WE and RE, at constant level. The gas sensor is 3-lead electrochemical cell shown in the attachment. When I am doing the amplifier which is the basic element of potentiostat, I found it...
See more

Part and Inventory Search

Back
Top