WM8746 Wolfson Microelectronics plc, WM8746 Datasheet - Page 7

• Manufacturer Part Number: WM8746
• Description: 24-bit, 192khz 6-channel Dac With Volume Control
• Manufacturer: Wolfson Microelectronics plc

WM8746
Notes:
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2.
3.
TERMINOLOGY
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w
Test Conditions
AVDD = DVDD = 5V, AGND = 0V = DGND = 0V, T
PARAMETER
Analogue Output Levels
Output level
Gain mismatch
channel-to-channel
Minimum resistance load
Maximum capacitance load
Output d.c. level
Power On Reset (POR)
POR threshold
with no signal applied. (No Auto-zero or Automute function is employed in achieving these results).
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).
the other. Normally measured by sending a full scale signal down one channel and measuring the other.
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.
CAP 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
Dynamic range (dB) - DNR is a measure of the difference between the highest and lowest portions of a signal.
THD+N (dB) - THD+N is a ratio, of the rms values, of (Noise + Distortion)/Signal.
Stop band attenuation (dB) - Is the degree to which the frequency spectrum is attenuated (outside audio band).
Channel Separation (dB) - Also known as Cross-Talk. This is a measure of the amount one channel is isolated from
Pass-Band Ripple - Any variation of the frequency response in the pass-band region.
SYMBOL
A
TEST CONDITIONS
= +25
To midrail or a.c.
To midrail or a.c.
(AVDD=5.0V)
(AVDD=3.3V)
Load = 10kΩ,
Load = 10kΩ,
(AVDD = 3.3V)
5V or 3.3V
0 dBFS,
0 dBFS,
coupled
coupled
o
C, fs = 48kHz, SCKI = 256fs unless otherwise stated.
MIN
AGND)/2
(AVDD1-
0.73
1.1
TYP
100
2.0
±1
1
1
PD, October 2008, Rev 4.2
MAX
Production Data
%FSR
UNIT
V
kΩ
kΩ
pF
V
V
rms
7