Audio codec electrical characteristics – Rainbow Electronics AT73C246 User Manual
Page 22
22
11050A–PMAAC–07-Apr-10
AT73C246
10. Audio Codec Electrical Characteristics
Unless otherwise specified: AVDD = 3.3V, T
A
= 25C, MCLK = 12.288MHz, F
S
= 48kHz. Master mode and 24-bit operation
on I
2
S port. All gains set to 0dB, audio effects are off. Noise measurements are made in the [20Hz-20kHz] band using the
A-Weighting filter. Distortion measurements are made from the 2
nd
to the 5
th
harmonic products of a 997Hz input sinewave.
Input sources have an internal impedance of 50 Ohms. Audio Path without mixing capability.
Table 10-1.
Audio Codec Bias
Symbol
Parameter
Comments
Min
Typ
Max
Units
AVDD
Operating Supply Voltage
2.7
3.3
3.6
V
I
DD
Supply Current
OFF
20
µA
STANDBY
1
mA
V
MID
Mid-Supply Reference Voltage
-1%
AVDD /
2
+1%
V
T
MID_ON
Time to charge V
MID
capacitor
From 0 to 95% of final value
350
ms/
μF
T
MID_OFF
Time to discharge V
MID
capacitor
From 0 to 95% of final value
700
ms/
μF
V
MICBIAS
Microphone Bias Reference
Voltage
No load.
AVDD
V
R
MICBIAS
Microphone Bias Reference
Voltage Internal Resistance
1.5
1.9
2.3
k
Ω
Table 10-2.
Line Record Path: Line or Auxiliary Input to ADC Output
Symbol
Parameter
Comments
Min
Typ
Max
Units
V
FS
Full Scale Input Voltage
Corresponds to 0dBFs digital
output signal.
AVDD /
3.3
V
RMS
SNR
Signal-to-Noise Ratio
AVDD = 3.3V
85
96
-
dB
AVDD = 2.7V
82
93
-
dB
DR
Dynamic Range
AVDD = 3.3V
85
96
-
dB
AVDD = 2.7V
82
93
-
dB
THD
Total Harmonic Distortion
-1dBFS digital output
-
-80
-74
dB
XTALK
Left / Right Channel separation
80
90
-
dB
G
LINE
Programmable Gain Range
-34
0
12
dB
Gain Step Size
-
1
-
dB
Mute Attenuation
80
-
-
dB
R
IN
Input Resistance
5.9
7
8.1
k
Ω
C
IN
Input Capacitance
-
-
10
pF
Table 10-3.
Microphone Record Path: Microphone Input to ADC Output
Symbol
Parameter
Comments
Min
Typ
Max
Units
V
FS
Full Scale Input Voltage
Corresponds to 0dBFs digital
output signal.
AVDD /
3.3
V
RMS
SNR
Signal-to-Noise Ratio
AVDD = 3.3V
85
96
-
dB
AVDD = 2.7V
82
93
-
dB