WM8731 Wolfson Microelectronics Ltd., WM8731 Datasheet - Page 11

• Manufacturer Part Number: WM8731
• Description: WM8731 : Low Power Audio Codec With Integrated Headphone Driver
• Manufacturer: Wolfson Microelectronics Ltd.

WM8731
Notes:
1.
2.
3.
4.
TERMINOLOGY
1.
2.
3.
4.
Test Conditions
AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T
256fs unless otherwise stated.
PARAMETER
Stereo Headphone Output
0dB Full scale output voltage
Max Output Power RL = 32
ohms
Max Output Power RL = 16
ohms
SNR (Note 3)
THD
Power Supply Rejection Ratio
Programmable Gain Maximum
Programmable Gain Minimum
Programmable Gain Step Size
Mute attenuation
Microphone Input to Headphone Output Side Tone Mode
0dB Full scale output voltage
SNR (Note 1, 3)
Power Supply Rejection Ratio
Programmable Attenuation
Maximum
Programmable Attenuation
Minimum
Programmable Attenuation Step
Size
Mute attenuation
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.
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.
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.
VMID decoupled with 10uF and 0.1uF capacitors (smaller values may result in reduced performance).
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).
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).
THD+N (dB) - THD+N is a ratio, of the rms values, of (Noise + Distortion)/Signal.
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.
SYMBOL
PSSR
PSSR
P
P
O
O
1kHz, R
1kHz, R
1kHz 100mVpp
20Hz to 20kHz
P
P
1kHz 100mVpp
20Hz to 20kHz
CONDITIONS
O
O
1kHz, 0dB
100mVpp
A-weighted
1kHz, 0dB
= 10mW rms
= 20mW rms
100mVpp
L
L
1kHz
1kHz
TEST
1kHz
1kHz
= 32 ohms @
= 32 ohms @
A
90
MIN
= +25
90
o
C, Slave Mode, fs = 48kHz, XTI/MCLK =
AVDD/3.3
AVDD/3.3
1.0 x
1.0 x
TYP
95
50
45
15
80
-73
6
3
30
40
97
50
45
80
6
1
AI Rev 2.3 August 2001
MAX
0.1
1.0
Advanced Information
60
40
Vrms
Vrms
UNIT
dB
dB
dB
dB
dB
dB
mW
mW
dB
dB
dB
dB
dB
dB
dB
dB
%
%
11