This is a PWM to analog voltage converter. Given an input PWM the output will be proportional to the duty cycle of the PWM signal.

It can work with any MCU, arduino, esp32, stm32 etc.. As long as the supply at the circuit is 3V-40V (tested up to 35V). For example a 1.8V (or less) pwm signal can be used as an input but you should power the circuit with at least 3V

There is an adjustable RC filter whose cutoff frequency can be adjusted from 33mHz to 33Hz

The circuit offers also the possibility to apply gain at the output. You can control the gain with the DIP switches:

ALL DOWN: G = 1.1

ON 1: G = 1.5

ON 2: G = 2

ON 3: G = 3

ON 4: Gain is adjustable using the potentiometer (gain up to 13)

Dimension (Assembled, LxWxH) : 48.7x34.4x19 mm

You can change the OPA4991 with the OPA4992 or OPA4990, they are pin-to-pin compatible. Below there's a brief comparison between them

ALL the waveforms you see here are produced by an ARDUINO NANO and my PWM to analog converter (with OPA4992)

Top-left: Smoothed square, Top-mid: Sine-Trapezoidal, Top-right: Mirrored sine

Bottom-left: "Squareish"-sine, Bottom-mid: Sine-Triangular, Bottom-right: Sine

There's also the possibility to apply gain:

34Vpp(0 to 34V) sine wave

Channel 1: Sine-Triangular 32Vpp

Channel 2: Mirrored sine 32Vpp

Here I've used two arduino pwm pins

NOTE: You're limited in frequency by your RC filters values, the more you approach the cutoff frequency the more the signal is attenuated