# DAC datasheet term confusion: FS-1LSB

In the Digital to analog converter HP16BME, I keep stumbling into " +FS - 1LSB " and I'm not sure what it means.

I mean, I still don't know the exact scale value because I don't know what FS stands for and what they mean by 1LSB in this example

• The DAC is set up so that full scale voltage corresponds to an input of 0x10000 and not 0xFFFF. So the highest voltage it can produce is slightly less than 10 V. Jun 29, 2015 at 8:10

## 1 Answer

"FS" means full-scale, which may be determined by an external voltage. "LSB" means Least Significant Bit - in this case, the voltage represented by one least significant bit. In a 16 bit DAC like yours, that's 1/216 of the full range.

Thus, "+FS-1LSB" means "full scale voltage less one least significant bit". For a full scale voltage of 10 volts, that's 10 volts - (1/216 * 10 volts) = 9.9985 volts.