What is the analog output for the input code 0101.

[charmcaster.engg]

A 4-bit R/2R digital-to-analog (DAC) converter has a reference of 5 volts. What is the analog output for the input code 0101.
I calculated one step voltage as 5/16=0.3125. How to do it further?

 

[Gryd3]

A 4-bit R/2R digital-to-analog (DAC) converter has a reference of 5 volts. What is the analog output for the input code 0101.
I calculated one step voltage as 5/16=0.3125. How to do it further?

What is the integer value of the binary number '0101' ?
(It's a number between 0 and 15 )
Once you know this, I'm sure the next step will click in.

 

[charmcaster.engg]

its 5. Should I multiply 5*0.3125?

 

[Gryd3]

its 5. Should I multiply 5*0.3125?

If you do, does the answer make sense?

 

[charmcaster.engg]

If you do, does the answer make sense?

The answer goes wrong.Then how to do it?

 

[Gryd3]

The answer goes wrong.Then how to do it?

What are you getting for an answer?
1.5625 V
or 1.66 V

Think about what the 0000 is... it's a 0
1111 is 15 ..
So how many steps from 0 to 15?
0 must output 0V, 15 must output 5V... so 5 must output ??V

 

[charmcaster.engg]

What are you getting for an answer?
1.5625 V
or 1.66 V

Think about what the 0000 is... it's a 0
1111 is 15 ..
So how many steps from 0 to 15?
0 must output 0V, 15 must output 5V... so 5 must output ??V

If 15 is 5V then 0101 is 1.66V. Then I multiply it with resolution to get 0.5187. Is it right?

 

[Gryd3]

I think you got a little side-tracked on this.

You have a 5V 4-bit DAC.
So we can determine the resolution in % or volts.
4-bit = 16 combinations. (or 15 steps)
1 / 15 steps = 6.66%
5V / 15 steps = 0.33V

So if we need to determine the output at '0101', we take the integer value which is 5, and multiply is by the resolution.
0.33V * 5 steps = 1.66V
6.66% * 5 steps = 0.33% ( 33% of 5V, is 1.66V )

 

[charmcaster.engg]

I think you got a little side-tracked on this.

You have a 5V 4-bit DAC.
So we can determine the resolution in % or volts.
4-bit = 16 combinations. (or 15 steps)
1 / 15 steps = 6.66%
5V / 15 steps = 0.33V

So if we need to determine the output at '0101', we take the integer value which is 5, and multiply is by the resolution.
0.33V * 5 steps = 1.66V
6.66% * 5 steps = 0.33% ( 33% of 5V, is 1.66V )

Thanks!