wm8770 Wolfson Microelectronics plc, wm8770 Datasheet - Page 8

• Manufacturer Part Number: wm8770
• Description: 24-bit, 192khz 8-channel Codec With Volume Control
• Manufacturer: Wolfson Microelectronics plc

WM8770
Notes:
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2.
3.
TERMINOLOGY
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w
Test Conditions
AVDD = 5V, DVDD = 3.3V, AGND = 0V, DGND = 0V, T
otherwise stated.
PARAMETER
Analogue input (AIN) to Analogue output (VOUT) (Load=10kΩ, 50pF, gain = 0dB) Bypass Mode
0dB Full scale output voltage
SNR (Note 1)
THD
Power Supply Rejection Ratio
Mute Attenuation
Supply Current
Analogue supply current
Digital supply current
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.
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.
VMID 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
PSRR
TEST CONDITIONS
1kHz 100mVpp
20Hz to 20kHz
DVDD = 3.3V
A
1kHz, -3dB
AVDD = 5V
1kHz, 0dB
1kHz, 0dB
100mVpp
= +25
o
C, fs = 48kHz, MCLK = 256fs, ADC/DAC in Slave Mode unless
MIN
AVDD/5
1.0 x
104
100
-90
-95
TYP
120
50
45
16
PD Rev 4.2 March 2008
MAX
Production Data
Vrms
UNIT
mA
mA
dB
dB
dB
dB
dB
dB
8