Adjustable Slewrate

[lukaev3]

Hello,

I have the following issue I cannot resolve. My output signal is from a DAC; it swings between -5V and 5V, outputting a square wave with variable duty cycle, Vmin, and Vmax.

Now to my question:

How can I have an adjustable slew rate on the rising and falling edges (it can be the same for both falling and rising)?

Example: When transitioning from 1V to 3V and back, the slew rate/ramp should be adjustable. The slew rate is preferably set by a voltage or current.

The slew rate should be a maximum of 1V/μs and a minimum of 1V/ms.

I have thought about using integrators, but they don't stop at my desired value.

Additionally, I also thought about transconductance amps, but they would have a droop at the end of the slope, right?

Another way would be a diode bridge, but I need to vary the current sink/source with one control signal, which is not that easy as it seems to me.

Thanks in advance!

[MasterT]

https://www.ti.com/lit/an/sboa218b/sboa218b.pdf?ts=1731566730893
https://www.ti.com/lit/ug/tidu026/tidu026.pdf?ts=1731542141599

 To make it adjustable use digital pot.

[David Hess]

Another way would be a diode bridge, but I need to vary the current sink/source with one control signal, which is not that easy as it seems to me.

Do you only have one analog control signal available?

[lukaev3]

I only have one DAC for my analog set point for now, but it would not be an issue to have a second...
As for the slewrate setting i was thinking of also using a 8bit dac so its not an issue

[PCB.Wiz]

I have the following issue I cannot resolve. My output signal is from a DAC; it swings between -5V and 5V, outputting a square wave with variable duty cycle, Vmin, and Vmax.
The slew rate should be a maximum of 1V/μs and a minimum of 1V/ms.
Additionally, I also thought about transconductance amps, but they would have a droop at the end of the slope, right?

I think an OTA could work quite well, you just need to power it with enough voltage it stays in the linear range. (eg +/-6V or more)
The OTA then works like a symmetric current limiter, so 1mA of bias and 1nF is 1V/us and 1uA of bias puts you in 1V/ms ballpark.
If you get a dual OTA, maybe you can use one channel to measure the current, and leverage the tracking ?