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  1. Closed: Re: Large numbers of paralleled DCDC modules?...more than datasheet recomends

    Heh it depends on where that internal C is. If it’s from primary switching nodes to the secondary or vice versa then you might need a multiple of that C to squelch the cm noise.

    Though really...
  2. Closed: Re: Does temperature variation affect SMPS control loops detrimentally?

    It was the topology shown here but flipped upside down using a P instead of N.

    https://youtu.be/eHGumuqh--Y

    That charged a cap (cog/npo) and was reset with another transistor. There were a...
  3. Closed: Re: Does temperature variation affect SMPS control loops detrimentally?

    PI is a type II compensator. PID with two more poles is TypeIII.

    How much voltage do you have? I made a custom 300khz modulator with a triangle using a transistor current source topology. But...
  4. Closed: Re: Relationship between settling accuracy and resolution

    Sure an amplifier is defined by vin*gain=Vout. So in a unity gain follower example with Vout=1 and gain of 1 million Vin must be 1uV or specifically the input might be 1.000001V into the...
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    Closed: Re: What is your design flow?

    I'll jump in. I've long used a program called "Keynote NF" for basic note taking. It has tabs and hierarchy and means that I have a good place to put anything I think of as soon as I think of it.
    ...
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    Closed: Re: Minimize heat in linear regulator

    You don’t want a divider in front of the regulator you want a single resistor in series with the input. Leave the input bypass caps right at the regulator input. Size the resistor to drop half the...
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    Closed: Re: Best topology for a 5kW DC-DC 48V input

    In general the more switches you have the less power each switch needs to process and therefore dissipate. As you point out higher switch topologies can also make better use of the transformer.
    ...
  8. Closed: Re: Large numbers of paralleled DCDC modules?...more than datasheet recomends

    I'm assuming this is your tethered drone application and I don't understand how isolation would be of any benefit. Everything is at the end of the same long cable and unless there is a large source...
  9. Closed: Re: SMPS circuit showing an oscillation in the output current...current monitor probl

    Yeah just rework to lift the allegro out of the circuit and short around it. Now you’ll only see the result of noise pickup.
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    Closed: Re: Input LC filter inductor is being shorted out

    0.7V of steady state ripple would surprise me. Run a simulation to see if it’s possible or not. Could get a dual package and put 2 in series if you’re worried. And/or put an R in series too.
    ...
  11. Closed: Re: How to display ASCII state when simulating one-hot encoding FSM ?

    State is declared as logic [3:0], not ASCII. You happened to use parameters with human readable names to define it but that doesn't make it ASCII.

    You'd need to explicitly code your own mux or...
  12. Closed: Re: Need suggestion to select an (1GHz) Oscilloscope (Tek 5 series Vs R&S RTO2000)

    You sure you have the right price? I see a starting price of 14500 for the 5 series with 350Mhz bandwidth.

    I recently added a Tek3 series to our lab and I like it. The UI isn't totally amazing...
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    Closed: Re: MOSFET Driver TLP350

    Yeah and understand that driver current is a peak value that tells you how quick the driver can slew the parasitic capacitance of your mosfet. The average current out of the driver will be tiny. It...
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    Closed: Re: Circuits for P, PI and PID controllers

    Two poles at the origin is stable. You can have 180 degree phase shift so long as it isn't at the crossover unity gain frequency.

    See this thread:...
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    Closed: Re: Single digital I/O circuit

    Digital isolators only go one direction. So you can't use one isolator channel as both an input or output.

    It is possible to multiplex multiple signals into the inputs of the isolator so long as...
  16. Closed: Re: Off-the-shelf tube needed for dummy load bank

    Reduced conduction losses doesn't need to be a priority in a load bank.
  17. Closed: Re: Which type of SMD capacitors are more robust against PCB flexion cracking?

    Yes I'd expect those are basically immune to board flex cracking.

    Personally I try to stay 1206 and below and make sure 1206 and above are flexiterm/automotive/J-lead (you can't avoid bigger...
  18. Closed: Re: Which type of SMD capacitors are more robust against PCB flexion cracking?

    I understand the metal or “J-lead” are better.
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    Closed: Re: Circuits for P, PI and PID controllers

    1) You'd want to choose a compensator topology that has 'enough' poles or zeros.

    TypeI: One pole
    Type II : 2 poles, one zero
    Type III: 3 poles, two zeros

    I: One pole
    PI: One pole, one zero...
  20. [SOLVED]Closed: Re: Different FETs for Top and Bottom FET in synchronous Buck converter

    Sure it makes sense and I've seen it done on large stepdown buck applications like this.

    Practically speaking you could choose a fet family that has multiple Rdson choices in the same package then...
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    [SOLVED]Closed: Re: Stopping a countdown timer from 9-0.

    if (counter == 0) begin
    counter <= 500000000;


    That resets the counter every time it reaches zero. Remove that and it should count once after being reset.
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    Closed: Re: Circuits for P, PI and PID controllers

    Control system 'tuning' may mean tuning the individual coefficients. It may also mean general control design. There is a lot more to control design than just tuning the bode plot of the compensator...
  23. Closed: Re: Adding an LC post filter can make an SMPS unstable....use RC filter instead?

    I highly doubt you can specify a useful RC filter without excessive losses or a gigantic C.

    Second, understand that any phase shift risks stability: a single extra pole and its 90 degree phase...
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    Closed: Re: P-channel Mosfet inverting control

    Yeah it looks generally sound.

    There are IC's that can do this too (load switches) such as FPF2700.
  25. Closed: Re: Adding an LC post filter can make an SMPS unstable....use RC filter instead?

    Well just follow the guidelines in your app note. Also see this one. They both address the problem.
    http://ridleyengineering.com/images/phocadownload/1%20second%20stage%20filter%20design.pdf
    ...
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