I am curious to know if there's a circuit or a way to utilize an enable pin to turn on/off an IC without a microcontroller.

 

I am curious to know if there's a circuit or a way to utilize an enable pin to turn on/off an IC without a microcontroller.

There are multiple ways to do this. We just need more information.
What will initiate this action?
What is the load, i.e. where is this signal to be used?
Can you provide a circuit schematic of your application?

 

There are multiple ways to do this. We just need more information.
What will initiate this action?
What is the load, i.e. where is this signal to be used?
Can you provide a circuit schematic of your application?

yes, so I have a gate driver (low side) that has an enable pin, and I would like to turn it on if it senses a signal from (pwm) coming from the source into the input of the driver, and I would like for it remain off if it doesn't detect that signal.

 

If the PWM peak voltage is the same as needed for the enable pin, then you could just use a series diode and capacitor to ground to rectify the signal to give a DC level.
How fast do you need to turn the enable on and off when the PWM signal appears and stops?
What is the PWM frequency?

 

If the PWM peak voltage is the same as needed for the enable pin, then you could just use a series diode and capacitor to ground to rectify the signal to give a DC level.
How fast do you need to turn the enable on and off when the PWM signal appears and stops?
What is the PWM frequency?

Thank you very much, this worked exactly like I needed.

 

If the PWM peak voltage is the same as needed for the enable pin, then you could just use a series diode and capacitor to ground to rectify the signal to give a DC level.
How fast do you need to turn the enable on and off when the PWM signal appears and stops?
What is the PWM frequency?

I would like to turn it on/off as fast as possible the frequency of the pwm is 4kHz

 

I would like to turn it on/off as fast as possible the frequency of the pwm is 4kHz

The theoretical fastest would be 1 cycle of the PWM or 250us.
In practice, because of the filter, it will be somewhat longer.

Below is the LTspice simulation of such a circuit:
It uses a CMOS CD40106 Schmidt trigger inverter to get a clean output pulse from the slow changing input.
The Enable output goes low about 335µs after the last PWM pulse.
It's shown for a very low duty-cycle which is the worst-case for this circuit.

 

"Output enable" works well for multiplexing 8 bits onto an 8 bit wide data bus to communicate with a multi digit display. And that was back in 1980.

 

Search for missing pulse detector using 555-timer circuit.

 

This discussion looks like a continuation of
https://forum.allaboutcircuits.com/...ary-pwm-with-dead-time-2.187731/#post-1743709
to me.
Did you not sort out the problem where there was a high current flowing when both low-side MOSFETs were on?
If not then trying to disable the driver isn't going to help.

 

This discussion looks like a continuation of
https://forum.allaboutcircuits.com/...ary-pwm-with-dead-time-2.187731/#post-1743709
to me.
Did you not sort out the problem where there was a high current flowing when both low-side MOSFETs were on?
If not then trying to disable the driver isn't going to help.

I got the problem sorted out. I will implement the enable pin on software. Thanks!

 

Another use for the enable pin is with an overcurrent detector, independent from the microcontroller.
When an excess current is detected in the output stage, the hardware pulls the enable pin down (or up, as appropriate) and turns off all transistors in the bridge. That way, you still get overcurrent protection if the microprocessor has crashed, or is doing something else.

 

I am curious to know if there's a circuit or a way to utilize an enable pin to turn on/off an IC without a microcontroller.

Now it is fairly clear that the TS was referencing some specific IC device, which the TS did not mention which device. So this was another case of the lack of mind reading ability for many of us leading to a lack of communication .

 

OK, the TS should have mentioned that the particular IC with an enable pin is an H-bridge motor driver. MANY ICs have enable pins, and even output enable pins.
Most of the real world does not include microprocessors. But they are becoming more common. The micro is especially handy for those unable to create logic circuits that work.

This is what is rather irksome about the whole "Nuts and Volts" agenda: the idea that nothing can be done without an arduino micro board and some of the add-ons. Not even a simple voltage comparator to switch on a light as it gets dark.

 

The micro is especially handy for those unable to create logic circuits that work.

Controversial - but I agree.

 

The Real World is analog! Even the switching portion, because semiconductor switches are not really instant, just fast, and almost all circuit elements exhibit a bit of reactance, even wires.

 

Most of the real world does not include microprocessors.

Not really true anymore !

The micro is especially handy for those unable to create logic circuits that work.

That comes off as a little condescending, IMO ?!

There were those that were probably saying that when IC's appeared and replaced discrete transistor circuits!

 

OK, Max, consider that the CNC machine without all of that analog I/O to make the motors run the right way at the right time is only a small box with a keypad, knobs, and a display. Fun to fiddle with but not very useful, except maybe to tell a machine operator what to do next.
And for the small projects, the same photo sensor with a comparator and adjustment pot can decide when to switch on the lights, but it does require more circuit analysis than an arduino package.

 

...
That comes off as a little condescending, IMO ?!

There were those that were probably saying that when IC's appeared and replaced discrete transistor circuits!

A lot condescending IMO. (from an expert on condescending per some here)

[condescending]
I usually hear this from people who don't actually understand embedded controller programming from the hardware end. The design abstraction to computer code from a deep understanding of hardware/math and physics seems alien to them.
[/condescending]

 

Does embedded programming include PLC code? And certainly there is a level of functionality below which having a micro, and developing code for it, does not make sense as far as the cost goes.