Production Data
WM8955L
Test Conditions
DCVDD = 1.5V, AVDD = HPVDD = 3.3V, TA = +25oC, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Analogue Reference Levels
Midrail Reference Voltage
Buffered Reference Voltage
Digital Input / Output
Input HIGH Level
VMID
VREF
–3%
–3%
AVDD/2
AVDD/2
+3%
+3%
V
V
VIH
VIL
0.7×DBVDD
0.9×DBVDD
V
V
V
V
Input LOW Level
0.3×DBVDD
0.1×DBVDD
Output HIGH Level
VOH
VOL
IOH = -1mA
IOL = 1mA
Output LOW Level
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 4.2 March 2006
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
