# What is LSB "unit"?

In a binary number, the LSB is the least significant bit (the MSB is the most significant bit). I do know that as well as binary scheme.

A DAC is a system that transforms a digital number (expressed in binary format) to an analogic number. I do know about this.

What is meaning of expressing units of "[LSB]" for a DAC. That is : what is meaning that a given number is expressed in terms of "LSB"? I would think that the unit is just "bit". So why saying [LSB]? What is the meaning?

• If you have a 10 bit DAC and Vref is 5V then the LBS is 5V/1024 = 4.88mV
– G36
Commented Jun 11, 2021 at 19:58
• Looks like a 12bit DAC scale with different resolutions / bit (lsb) vs byte LSB so 4096 lsb’s are either 0.5V or 1.0V full scale (FS) Commented Jun 11, 2021 at 20:02
• No pun intended but when ambiguous (a bit) , bits are b and bytes are B, otherwise may use LSB for bits when not ambiguous. Then analog references determine resolution for full scale Commented Jun 11, 2021 at 20:05
• For DAC LSB is the smallest increment/decrement we can get at the output
– G36
Commented Jun 11, 2021 at 20:07
• Within a word each bit has a different value, with the most significant bit being valued at 2^(word_length-1) times larger than the least significant bit. Saying least significant bit makes it explicit which you are referring to, although typically the meaning can be inferred from context so people would understand if you just said "bit". Commented Jun 11, 2021 at 20:18