wm9709 Wolfson Microelectronics plc, wm9709 Datasheet - Page 5

• Manufacturer Part Number: wm9709
• Description: Ac-link Interface Audio Dac
• Manufacturer: Wolfson Microelectronics plc

Production Data
Notes:
1.
2.
3.
TERMINOLOGY
1.
2.
3.
4.
SERIAL INTERFACE TIMINGS
WARM RESET
w
COLD RESET
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.
SNR measured with A-weight filter is typically 2dB better than with CCIR2k filter, or 20kHz low pass filter.
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).
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.
Dynamic range (dB) - DNR is a measure of the ratio between the largest and smallest usable signals. 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= 42dB, DNR= 102dB).
THD+N (dB) - THD+N is a ratio, of the rms values, of (Noise + Distortion)/Signal.
Test Conditions:
AVDD = 5V, AGND = 0V, DVDD = 3.3V, DGND = 0V, TA = 25
measurements are taken at 10% to 90% VDD, unless otherwise stated.
All the following timing information is guaranteed by design, but not tested in production.
Figure 1 Cold Reset Timing
Not supported by WM9709
PARAMETER
RESETB active low pulse width
RESETB inactive to BITCLK
startup delay
RESETB
BITCLK
t
RST_LOW
SYMBOL
t
t
RST_LOW
RST2CLK
t
RST2CLK
162.8
MIN
1.0
o
C, unless otherwise stated. All
TYP
PD Rev 1.3 February 2003
MAX
WM9709
UNIT
ns
s
5