WM8731 / WM8731L
Production Data
Test Conditions
AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, TA = +25oC, Slave Mode, fs = 48kHz, XTI/MCLK =
256fs unless otherwise stated.
Mute attenuation
1kHz, 0dB
80
dB
Stereo Headphone Output
0dB Full scale output voltage
1.0 x
AVDD/3.3
30
Vrms
mW
Max Output Power
PO
RL = 32Ω
RL = 16Ω
50
Signal to Noise Ratio (Note 1, 3)
Total Harmonic Distortion
SNR
THD
A-weighted
90
97
dB
%
1kHz, RL = 32Ω
PO = 10mW rms (-5dB)
1kHz, RL = 32Ω
PO = 20mW rms (-2dB)
1kHz 100mVpp
20Hz - 20kHz, 100mVpp
1kHz
0.056
-65
0.1
60
dB
%
0.56
-45
1.0
40
dB
dB
Power Supply Rejection Ratio
PSRR
50
45
Programmable Gain
-73
0
6
dB
dB
dB
Programmable Gain Step Size
Mute attenuation
1kHz
1
1kHz, 0dB
80
Microphone Input to Headphone Output Side Tone Mode
0dB Full scale output voltage
1.0 x
AVDD/3.3
95
Vrms
dB
Signal to Noise Ratio
(Note 1,3)
SNR
90
Power Supply Rejection Ratio
PSRR
1kHz 100mVpp
50
45
dB
20Hz to 20kHz
100mVpp
Programmable Attenuation
1kHz
1kHz
6
15
dB
dB
Programmable Attenuation Step
Size
3
Mute attenuation
1kHz, 0dB
80
dB
Notes:
1. Ratio of output level with 1kHz full scale input, to the output level with the input short circuited, measured ‘A’ weighted over a 20Hz
to 20kHz bandwidth using an Audio analyser.
2. Ratio of output level with 1kHz full scale input, to the output level with all zeros into the digital input, measured ‘A’ weighted over a
20Hz to 20kHz bandwidth.
3. All performance measurements done with 20kHz low pass filter, and where noted an A-weight filter. Failure to use such a filter will
result in higher THD+N and lower SNR and Dynamic Range 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.
4. VMID decoupled with 10uF and 0.1uF capacitors (smaller values may result in reduced performance).
TERMINOLOGY
1. Signal-to-noise ratio (dB) - SNR is a measure of the difference in level between the full scale output and the output
with no signal applied. (No Auto-zero or Automute function is employed in achieving these results).
2. Dynamic range (dB) - DR is a measure of the difference between the highest and lowest portions of a signal. Normally
a THD+N measurement at 60dB below full scale. The measured signal is then corrected by adding the 60dB to it. (e.g.
THD+N @ -60dB= -32dB, DR= 92dB).
3. THD+N (dB) - THD+N is a ratio, of the rms values, of (Noise + Distortion)/Signal.
4. Channel Separation (dB) - Also known as Cross-Talk. This is a measure of the amount one channel is isolated from
the other. Normally measured by sending a full scale signal down one channel and measuring the other.
PD, Rev 4.9, October 2012
w
9
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
