Pre-Production
WM8976
ELECTRICAL CHARACTERISTICS
Test Conditions
DCVDD=1.8V, AVDD=DBVDD=SPKVDD= 3.3V, TA = +25oC, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise
stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Microphone Preamp Inputs (LIP, LIN, RIP)
Full-scale Input Signal Level –
note this changes in proportion
to AVDD (Note 1)
VINFS
PGABOOST = 0dB
INPPGAVOL = 0dB
1.0
0
Vrms
dBV
Mic PGA equivalent input noise
At 35.25dB
gain
0 to 20kHz
150
uV
Input resistance
RMICIN
RMICIN
RMICIN
RMICIP
CMICIN
Gain set to 35.25dB
Gain set to 0dB
1.6
47
75
94
10
kΩ
kΩ
kΩ
kΩ
pF
Gain set to -12dB
L/RIP2INPPGA = 1
MIC Programmable Gain Amplifier (PGA)
Programmable Gain
-12
-12
35.25
dB
dB
dB
Programmable Gain Step Size
Mute Attenuation
Guaranteed monotonic
0.75
120
Selectable Input Gain Boost (0/+20dB)
Gain Boost on PGA input
Boost disabled
Boost enabled
0
dB
dB
dB
20
Gain range from AUXL or L2
input to boost/mixer
+6
Gain step size to boost/mixer
3
dB
Auxilliary Analogue Inputs (AUXL, AUXR)
Full-scale Input Signal Level
(0dB) – note this changes in
proportion to AVDD
VINFS
AVDD/3.3
0
Vrms
dBV
Input Capacitance
CMICIN
10
pF
Automatic Level Control (ALC)
Target Record Level
-22.5
-12
-1.5
dB
ms
ms
Programmable gain
35.25
Gain Hold Time (Note 3,5)
tHOLD
tDCY
MCLK = 12.288MHz
(Note 3)
0, 2.67, 5.33, 10.67, … , 43691
(time doubles with each step)
3.3, 6.6, 13.1, … , 3360
Gain Ramp-Up (Decay) Time
(Note 4,5)
ALCMODE=0 (ALC),
MCLK=12.288MHz
(Note 3)
(time doubles with each step)
ALCMODE=1 (limiter),
MCLK=12.288MHz
(Note 3)
0.73, 1.45, 2.91, … , 744
(time doubles with each step)
Gain Ramp-Down (Attack) Time
(Note 4,5)
tATK
ALCMODE=0 (ALC),
MCLK=12.288MHz
(Note 3)
0.83, 1.66, 3.33, … , 852
ms
(time doubles with each step)
ALCMODE=1 (limiter),
MCLK=12.288MHz
(Note 3)
0.18, 0.36, 0.73, … , 186
(time doubles with each step)
Mute Attenuation
120
dB
Analogue to Digital Converter (ADC)
Signal to Noise Ratio (Note 6)
Total Harmonic Distortion
(Note 7)
SNR
THD
A-weighted, 0dB gain
-3dBFS input
95
dB
dB
-84
PP Rev 3.0 April 2006
7
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
