WM8940
Pre-Production
ELECTRICAL CHARACTERISTICS
Test Conditions
DCVDD = 1.8V, AVDD = DBVDD = 3.3V, 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 Input PGA Inputs (MICN, MICP)
INPPGAVOL and PGABOOST = 0dB
Full-scale Input Signal Level – Single-
ended input via LIN/RIN 1
AVDD/3.3
Vrms
Vrms
Full-scale Input Signal Level –
Pseudo-differential input 1,2
AVDD*0.7/
3.3
Input PGA equivalent input noise
INPPGAVOL = +35.25dB
No input signal
76.5
dB
0 to 20kHz
MICN input resistance
MICN input resistance
MICN input resistance
MICP input resistance
Input Capacitance
INPPGAVOL = +35.25dB
INPPGAVOL = 0dB
INPPGAVOL = -12dB
All gain settings
1.6
47
71
94
10
kΩ
kΩ
kΩ
kΩ
pF
dB
All analogue input pins
Input PGA Programmable Gain
Gain adjusted by
INPPGAVOL
-12
+35.25
Programmable Gain Step Size
Input PGA Mute Attenuation
Input Gain Boost
Guaranteed monotonic
INPPGAMUTE
0.75
108
0
dB
dB
dB
dB
PGABOOST= 0
Input Gain Boost
PGABOOST = 1
+20
Auxiliary Analogue Inputs (AUX)
Full-scale Input Signal Level 2
AVDD/3.3
20
Vrms
Input Resistance
Input boost and mixer
enabled, at 0dB gain
All analogue Inputs
kΩ
Input Capacitance
10
pF
dB
Gain range from AUX input PGA
mixers
-12
+6
Gain adjusted by
AUX2BOOSTVOL
AUXLBOOSTVOL and
3
dB
AUXRBOOSTVOL step size
Analogue to Digital Converter (ADC) - Input from MICN and MICN in differential configuration to input PGA
INPPGAVO, PGABOOST and ADCVOL = 0dB
Signal to Noise Ratio 3
SNR
A-weighted
AVDD=3.3V
91
-83
-77
100
dB
dB
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
Channel Separation 6
THD
-1dBV Input
AVDD=3.3V
THD+N
-1dBV Input
dB
AVDD=3.3V
1kHz full scale input signal
dBFS
Pre-Production, Rev 3.0, February 2007
8
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
