Resistive behaviour using a buck

[snoop33]

Hi,

What would be your method for implementing a buck that simulates a resistor feeding into a large super-capacitor?

My end goal is to set a resistive equivalent load by MCU DAC. My initial thoughts were to use an op-amp deriving a target using the dc & dac, which is compared to a high current sense, which drives either a comparator for hysteretic mode or triggers fault on a fixed duty PWM signal.

But perhaps there's a more appropriate way...?

[snoop33]

I've been playing and made it work using hysteretic buck mode.

The challenge now is how to make a voltage or PWM controlled attenuator to control it.