Production Data

WM9709

w

PD Rev 1.3 February 2003

5

Notes:

1.

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.

2.

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.

3.

SNR measured with A-weight filter is typically 2dB better than with CCIR2k filter, or 20kHz low pass filter.

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.

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.

3.

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).

4.

THD+N (dB) - THD+N is a ratio, of the rms values, of (Noise + Distortion)/Signal.

SERIAL INTERFACE TIMINGS

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.

COLD RESET

RESETB

BITCLK

t

RST_LOW

t

RST2CLK

Figure 1 Cold Reset Timing

PARAMETER

SYMBOL

MIN

TYP

MAX

UNIT

RESETB active low pulse width

1.0

µs

RESETB inactive to BITCLK

startup delay

162.8

ns

WARM RESET

Not supported by WM9709