Is this what you want?
Any of the ENx inputs logic high will apply power to the circuit.
M1 must be a logic-level P-MOSFET (Max Vgs(th) of 1.5V).

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What I essentially wanted was to create a generic enable input that would turn on/off all the ICs used in the circuit. The above configuration is similar to what I provided in post #12 in the sense it enables/disables: it decides whether to supply the IC or not. I am aware that there is no easy way to “turn on or off” all the devices used and in some way we must intervene in the nets through which they are supplied. But from what I have seen in other applications on the internet and the simulation result of post#12, I feel like doing this direct intervention is not optimal. At this point I wonder how does systems like remote controlling works. Do they again intervene with the devices’ power supplies but just in a safer/more efficient way or do they adopt another simple methodology like what I did, manipulating the inputs to force the desired enable input - IC output relationship?

 

Sorry, but I've become a little lost in exactly what you are trying to do, and why turning off the circuit power is not what you want.

 

Sorry, but I've become a little lost in exactly what you are trying to do, and why turning off the circuit power is not what you want.

I am sorry if I couldn’t express it clearly. What I want to achieve with this enable operation was to shut down every IC when EN=low in the circuit and allow them to operate when EN=high. In my current configuration, for example, the PWM signals are generated no matter what. Only if the comparator output or enable input is low, input to the gate driver is low. If there was a single pin which was able to control whether these components operate or not rather than controlling their outputs, I feel like that would mean more control on the circuit. and as I said before I am not able to create a configuration without conditioning the power supply lines of all these components. what frustrates me is that this is discouraged and not guaranteed to work properly, when enabled and powered, my gate driver didnt work the way I wanted for instance(post#12). Then what is the alternative? Is there a clean way of such controlling?

 

Is there a clean way of such controlling?

Possibly.
List all the components you want to control with the enable signal.

 

Possibly.
List all the components you want to control with the enable signal.

All the components that need an external supply to work..opamps, LTC labeled models.. I feel like controlling the power supplies is a must if there is no builtin disable mode for the ICs used. When it comes to doing it in a clean way, one idea is creating a DC bus for supplying power(with a divider network for different power needs) and controlling this only net with something like an optoisolator or SSR. This may not eliminate the dependency to switches as the solutions mentioned again use transistors internally. Unless they significantly disturb the normal operation of components such as by causing a decrease in the output voltage, switches are fine. This was not the case for my first attempt.

 

Do you have any MOSFET models suitable for high frequency switching, up to 500Khz? I tried to choose one with minimal gate capacitance, gate charge and Ron. The Vds must be 100V minimum. Heres the best I could find for now from the default LTspice library. I had a quick look at digikey but couldnt find a proper one. This one is fine with frequencies like 20kHz but can not fully reach the source voltage level when the likes of 300kHz is present at the gate driver output.

 

Do you have any MOSFET models suitable for high frequency switching, up to 500Khz? I tried to choose one with minimal gate capacitance, gate charge and Ron. The Vds must be 100V minimum. Heres the best I could find for now from the default LTspice library. I had a quick look at digikey but couldnt find a proper one. This one is fine with frequencies like 20kHz but can not fully reach the source voltage level when the likes of 300kHz is present at the gate driver output.

Is this related to the rest of your post?

What load do you have that needs a 500kHz, 100V signal?

 

Is this related to the rest of your post?

What load do you have that needs a 500kHz, 100V signal?

It is. The PWM signal frequency that drives the gate driver is to reach 500k in the current configuration. This may be a bit too much for any easily accessible MOSFET but it is subject to change, the upper treshold for frequency can be set as 200kHz or even less. But I want the design to be comfortable with a few hundresd of kHzs. This chopper will be used(or at least it is supposed to) alongside a DC motor normally operating at 28V and PWM drive starts when 36V is reached due to the the potential increase in the busbar. 100V Vds was a design specification recommended and I just try to comply with it as I dont know about the DC motor itself and how much the busbar voltage can go up. I think the margin between the Vsource aand Vout may cause issues related to power consumption and overvoltage effects on the motor. I tried some models from toshiba with low gate charge and Ron here and the margin were different for each, which is a bit surprising to me given that they all have close values of parameters that affect the rise and fall times. https://toshiba.semicon-storage.com...|numeric|4,5&f[]=5|N-ch&f[]=28|10V Gate Drive
SSM6K361NU_G0_00 was not bad, 10V being close to the absolute max of Vgs and bigger than usual drive voltages associated.

 

Typically the PWM frequency to a motor is, at most, a few tens of kilohertz.
Why do you need to go so high, which just increases the switching losses?

 

Typically the PWM frequency to a motor is, at most, a few tens of kilohertz.
Why do you need to go so high, which just increases the switching losses?

I wanted to achieve high frequencies both because I dont know how much performance is demanded from this circuit and I lack the experience to have a solid guess. my first design was a simpler one with 2kHz and I was told to increase this to tens or even hundreds of Hzs. An upper bound of 100-125kHz probably would do the trick and but having a range as wide as possible seemed like success to me since it means more control. You are %100 right about switching losses though, minimizing the Ron alone wont be enough in that sense when working with such frequency levels.

 

I was told to increase this to tens or even hundreds of Hzs.

By whom?

 

By whom?

this is a new design spec added for me to learn more about frequency and duty cycle control

 

"" An upper bound of 100-125kHz probably would do the trick and but having a range as wide as possible seemed like success to me since it means more control. ""
This is an absurdity, and will not produce "more-control" in any way.

When controlling a Motor using a PWM scheme,
the only legitimate purpose for using a Frequency above ~1kHz is to reduce or eliminate Audible-Noise.
There is zero advantage to using any Frequency higher than roughly ~25kHz to PWM-Control a Motor,
unless You are trying to make all the components microscopic in size.

On a more positive note,
You probably will learn a lot of things NOT to do,
although learning from other peoples mistakes is
always much less expensive than learning from your own mistakes.

If You would provide an extensive outline of the requirements and specifications of this Project,
instead of asking questions regarding your
guesses and assumptions about how those end-goals might be accomplished,
You would get far more useful advice, instead of just causing frustration and confusion.

The first question should be .......... is this intended to be a Battery-Powered-Device ?

Second, what is the measured "Locked-Rotor-Amps", and the Voltage-Rating of your Motor ?

Third, what purposes might be served by controlling the Motor with a PWM-scheme ?

Forth, what overall purpose(s) does the Motor serve ?
.
.
.

 

"" An upper bound of 100-125kHz probably would do the trick and but having a range as wide as possible seemed like success to me since it means more control. ""
This is an absurdity, and will not produce "more-control" in any way.

When controlling a Motor using a PWM scheme,
the only legitimate purpose for using a Frequency above ~1kHz is to reduce or eliminate Audible-Noise.
There is zero advantage to using any Frequency higher than roughly ~25kHz to PWM-Control a Motor,
unless You are trying to make all the components microscopic in size.

On a more positive note,
You probably will learn a lot of things NOT to do,
although learning from other peoples mistakes is
always much less expensive than learning from your own mistakes.

If You would provide an extensive outline of the requirements and specifications of this Project,
instead of asking questions regarding your
guesses and assumptions about how those end-goals might be accomplished,
You would get far more useful advice, instead of just causing frustration and confusion.

The first question should be .......... is this intended to be a Battery-Powered-Device ?

Second, what is the measured "Locked-Rotor-Amps", and the Voltage-Rating of your Motor ?

Third, what purposes might be served by controlling the Motor with a PWM-scheme ?

Forth, what overall purpose(s) does the Motor serve ?
.
.
.

Sorry for the vague expressions and my guesses. I am not an expert in the area, just trying my best to reason things that may not be a concern having prior experience. About your questions, yes this is a battery powered device, this PWM scheme is supposed to help dissipating the excess energy in case of a voltage increase in the motor supply. My first model was 2kHz with duty cycle error up to %4.