LSB Value depends upon the reference value and the number of input bits the DAC has.
Since one LSB is equal to VREF / 2n, better accuracy (lower error) can be realized if we did either (or both) of two things: (1) use a higher resolution converter (more bits) and/or (2) use a smaller reference voltage.
- The problem with higher resolution (more bits) is the cost. The problem with reducing the reference voltage is that whatever noise is present at the output is a larger part of the LSB if the reference is very small. However, noise is always a problem when it is desired to be very accurate. Careful design and layout will help to minimize noise.
