Production Data
WM8955BL
Test Conditions
o
DCVDD = 1.5V, AVDD = HPVDD = 3.3V, T
A
= +25 C, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
Analogue Reference Levels
Midrail Reference Voltage
Buffered Reference Voltage
Digital Input / Output
Input HIGH Level
Input LOW Level
Output HIGH Level
Output LOW Level
V
IH
V
IL
V
OH
V
OL
I
OH
= -1mA
I
OL
= 1mA
0.9×DBVDD
0.1×DBVDD
0.7×DBVDD
0.3×DBVDD
V
V
V
V
VMID
VREF
–3%
–3%
AVDD/2
AVDD/2
+3%
+3%
V
V
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
TERMINOLOGY
1.
2.
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.
3.
4.
w
PD Rev 4.1 February 2007
7
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
