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Production Data
WM8978
w
PD, Rev 4.5, October 2011
9
Test Conditions
DCVDD=1.8V, AVDD=DBVDD=SPKVDD= 3.3V, T
A
= +25
o
C, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise stated.
PARAMETER SYMBOL
TEST
CONDITIONS
MIN
TYP
MAX
UNIT
Speaker Output (LOUT2, ROUT2 with 8
bridge tied load, INVROUT2=1)
Full scale output voltage, 0dB
gain. (Note 9)
SPKBOOST=0 SPKVDD/3.3 Vrms
SPKBOOST=1
(SPKVDD/3.3)*1.5
Output Power
P
O
Output power is very closely correlated with THD; see below
Total Harmonic Distortion
THD P
O
=200mW, R
L
= 8
,
SPKVDD=3.3V
0.04
-68
%
dB
P
O
=320mW, R
L
= 8
,
SPKVDD=3.3V
1.0
-40
%
dB
P
O
=500mW, R
L
= 8
,
SPKVDD=5V
0.02
-74
%
dB
P
O
=860mW, R
L
= 8
,
SPKVDD=5V
1.0
-40
%
dB
Signal to Noise Ratio
SNR SPKVDD=3.3V,
R
L
= 8
90 dB
SPKVDD=5V,
R
L
= 8
90 dB
Power Supply Rejection Ratio
(50Hz-22kHz)
PSRR
R
L
= 8
BTL
80
dB
R
L
= 8
BTL
SPKVDD=5V (boost)
69 dB
OUT3/OUT4 Outputs (with 10k
/ 50pF load)
Full-scale output voltage, 0dB
gain (Note 10)
OUT3BOOST=0/
OUT4BOOST=0
SPKVDD/3.3 Vrms
OUT3BOOST=1
OUT4BOOST=1
(SPKVDD/3.3)*1.5
Vrms
Signal to Noise Ratio (Note 6)
SNR A-weighted 98 dB
Total Harmonic Distortion
(Note 7)
THD R
L
= 10 k
full-scale signal
-84 dB
Channel Separation (Note 8)
1kHz signal
100
dB
Power Supply Rejection Ratio
(50Hz-22kHz)
PSRR
R
L
= 10k
52
dB
R
L
= 10k
SPKVDD=5V
(boost)
56 dB
Microphone Bias
Bias Voltage
V
MICBIAS
MBVSEL=0
0.9*AVDD
V
MBVSEL=1
0.65*AVDD
V
Bias Current Source
I
MICBIAS
3
mA
Output Noise Voltage
Vn
1K to 20kHz
15
nV/
Hz
Digital Input / Output
Input HIGH Level
V
IH
0.7
DBVDD
V
Input LOW Level
V
IL
0.3
DBVDD V
Output HIGH Level
V
OH
I
OL
=1mA 0.9
DBVDD
V
Output LOW Level
V
OL
I
OH
-1mA
0.1xDBVDD
V
Input capacitance
10
pF
Input leakage
50
pA
Содержание WM8978
Страница 11: ...Production Data WM8978 w PD Rev 4 5 October 2011 11 SPEAKER OUTPUT THD VERSUS POWER...
Страница 14: ...WM8978 Production Data w PD Rev 4 5 October 2011 14 AUDIO PATHS OVERVIEW...
Страница 46: ...WM8978 Production Data w PD Rev 4 5 October 2011 46 Figure 22 ALC Operation Above Noise Gate Threshold...
Страница 55: ...Production Data WM8978 w PD Rev 4 5 October 2011 55 Figure 26 Left Right Output Channel Mixers...
Страница 60: ...WM8978 Production Data w PD Rev 4 5 October 2011 60 Figure 29 Speaker Outputs LOUT2 and ROUT2...