WM8994 datasheet(30/359 Pages) WOLFSON

30 / 359 page

WM8994

Production Data

PD, April 2012, Rev 4.4

TERMINOLOGY

Signal-to-Noise Ratio (dB) – SNR is a measure of the difference in level between the maximum full scale output signal

and the output with no input signal applied.

Total Harmonic Distortion (dB) – THD is the level of the rms value of the sum of harmonic distortion products relative

to the amplitude of the measured output signal.

Total Harmonic Distortion plus Noise (dB) – THD+N is the level of the rms value of the sum of harmonic distortion

products plus noise in the specified bandwidth relative to the amplitude of the measured output signal.

Power Supply Rejection Ratio (dB) - PSRR is the ratio of a specified power supply variation relative to the output

signal that results from it. PSRR is measured under quiescent signal path conditions.

Common Mode Rejection Ratio (dB) – CMRR is the ratio of a specified input signal (applied to both sides of a

differential input), relative to the output signal that results from it.

Channel Separation (L/R) (dB) – left-to-right and right-to-left channel separation is the difference in level between the

active channel (driven to maximum full scale output) and the measured signal level in the idle channel at the test

signal frequency. The active channel is configured and supplied with an appropriate input signal to drive a full scale

output, with signal measured at the output of the associated idle channel.

Multi-Path Crosstalk (dB) – is the difference in level between the output of the active path and the measured signal

level in the idle path at the test signal frequency. The active path is configured and supplied with an appropriate input

signal to drive a full scale output, with signal measured at the output of the specified idle path.

Mute Attenuation – This is a measure of the difference in level between the full scale output signal and the output with

mute applied.

All performance measurements carried out with 20kHz low pass filter, and where noted an A-weighted filter. Failure to

use such a filter will result in higher THD and lower SNR readings than are found in the Electrical Characteristics. The

low pass filter removes out of band noise; although it is not audible it may affect dynamic specification values.

WM8994 Datasheet(PDF) 30 Page - Wolfson Microelectronics plc