I am not sure I understand what you said? Should I remove the 1k pull down resistor at the gate of the mosfet or the pull at the drain?
Yes the DSC has CMOS output (see attachment). I don't have an OP on me now, so I can't just make a RC circuit at the outputs after my transistor? I thought it could be this easy
You cannot use a single FET and a resistor to shift the level to 5V. The problem is the FET has near 0 ohms when it is pulling down. The 10K resistor has 10K Ohms when it is pulling up. You need an active pullup like another FET. Just like the DSC output stage.
If you use your circuit, here is what will happen:
0% duty PWM cycle:- 0V out. That sounds good.
100% PWM duty cycle:- 5V out. Sounds good too.
50% PWM duty Cycle:- 1.66666V out> Wanted 2.5V, so a big FAIL.
The 74hc4053 is a fairly common IC that can be used to shift levels. The multiplexer inputs are connected to +5V and 0V, and the multiplexer is switched by the DSC output. The multiplexer output will be either 5V or 0V.
And vk6zgo is right about the time constant. The longer the time constant, the less ripple will be in the output voltage, but the slower it will change when you change the PWM duty cycle. So you need to find the best compromise.
Richard.