wm8775 Wolfson Microelectronics plc, wm8775 Datasheet - Page 6

• Manufacturer Part Number: wm8775
• Description: 24-bit, 96khz Adc With 4 Channel I/p Multiplexer
• Manufacturer: Wolfson Microelectronics plc

WM8775
ELECTRICAL CHARACTERISTICS
Notes:
1.
2.
3.
4.
5.
w
Test Conditions
AVDD = 5V, DVDD = 3.3V, AGND = 0V, DGND = 0V, T
PARAMETER
Digital Logic Levels (TTL Levels)
Input LOW level
Input HIGH level
Output LOW
Output HIGH
Analogue Reference Levels
Reference voltage
Potential divider resistance
ADC Performance
Input Signal Level (0dB)
SNR (Note 1,2)
SNR (Note 1,2)
Dynamic Range (note 2)
Total Harmonic Distortion (THD)
ADC Channel Separation
Programmable Gain Step Size
Programmable Gain Range
(Analogue)
Programmable Gain Range
(Digital)
Analogue Mute Attenuation
(Note 5)
Power Supply Rejection Ratio
Supply Current
Analogue supply current
Digital supply current
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).
All performance measurement done using certain timing conditions (please refer to section ‘Digital Audio Interface’).
A full digital MUTE can be achieved if the ADC gain (LAG/RAG) is set to minimum.
SYMBOL
PSRR
V
R
V
V
V
V
VMID
VMID
OH
OL
IH
IL
A-weighted, 0dB gain
A-weighted, 0dB gain
1kHz Input, 0dB gain
TEST CONDITIONS
A-weighted, -60dB
full scale input
@ fs = 48kHz
1kHz, -1dBFs
1kHz 100mVpp
1 kHz, 0dBFs
@ fs = 96kHz
20Hz to 20kHz
DVDD = 3.3V
A
AVDD = 5V
1kHz Input
1kHz Input
1kHz Input
64xOSR
100mVpp
I
I
= +25
OH
OL
=1mA
=1mA
o
C, fs = 48kHz, MCLK = 256fs unless otherwise stated.
0.9 x DVDD
0.25
93
MIN
2.0
-21
-82
AVDD/5
AVDD/2
1.0 x
102
99
TYP
102
50k
-92
-95
0.5
4.5
90
76
50
45
48
PD, Rev 4.4, October 2008
0.1 x DVDD
MAX
0.75
+24
-85
0.8
+0
Production Data
Vrms
UNIT
mA
mA
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
Ω
V
V
V
V
V
6