The internally-generated noise of a voltage reference causes a dynamic error that degrades the signal to- noise ratio (SNR) of a data converter. Low frequency V_REF noise is specified over the 0.1 Hz to 10 Hz bandwidth as a peak-to-peak value (in µV or ppm). Filtering below 10 Hz is impractical, so the low-frequency noise contributes directly to the total reference error.

When calculating the total error in V_REF it is best to separate error specifications where a maximum value is guaranteed (TC, initial accuracy, load regulation, line regulation) and those where only a typical value is provided (0.1 Hz to 10 Hz noise, thermal hysteresis, and long-term stability). Other than initial accuracy, the guaranteed specifications are all linear coefficients and their contribution to the total error can be calculated based on the operating ranges of the reference (temperature range, load current, and input voltage).