WM8978 Wolfson Microelectronics Ltd., WM8978 Datasheet - Page 9

• Manufacturer Part Number: WM8978
• Description: The WM8978 is a low power, high quality stereo codec designed for portable applications such as Digital still camera or Digital Camcorde
• Manufacturer: Wolfson Microelectronics Ltd.

Preliminary Technical Data
w
Test Conditions
DCVDD=1.8V, AVDD=DBVDD=SPKVDD= 3.3V, T
stated.
PARAMETER
Speaker Output (LOUT2, ROUT2 with 8
Full scale output voltage, 0dB
gain. (Note 9)
Output Power
Total Harmonic Distortion
Signal to Noise Ratio
Power Supply Rejection Ratio
(50Hz-22kHz)
OUT3/OUT4 Outputs (with 10k
Full-scale output voltage, 0dB
gain (Note 10)
Signal to Noise Ratio (Note 6)
Total Harmonic Distortion
(Note 7)
Channel Separation (Note 8)
Power Supply Rejection Ratio
(50Hz-22kHz)
Microphone Bias
Bias Voltage
Bias Current Source
Output Noise Voltage
Digital Input / Output
Input HIGH Level
Input LOW Level
Output HIGH Level
Output LOW Level
Input capacitance
Input leakage
/ 50pF load)
SYMBOL
V
I
PSRR
PSRR
MICBIAS
SNR
SNR
MICBIAS
THD
THD
V
V
V
P
Vn
V
OH
OL
IH
O
IL
bridge tied load, INVROUT2=1)
A
P
P
P
P
SPKVDD=5V (boost)
SPKVDD=5V (boost)
TEST CONDITIONS
O
O
O
O
= +25
OUT3BOOST=0/
OUT4BOOST=0
OUT3BOOST=1
OUT4BOOST=1
=200mW, R
=320mW, R
=500mW, R
=860mW, R
SPKVDD=3.3V,
full-scale signal
SPKVDD=3.3V
SPKVDD=3.3V
SPKBOOST=0
SPKBOOST=1
SPKVDD=5V,
SPKVDD=5V
SPKVDD=5V
R
R
1K to 20kHz
1kHz signal
MBVSEL=0
MBVSEL=1
A-weighted
R
R
R
L
L
I
I
R
R
L
OL
o
L
L
OH
= 8
= 8
C, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise
= 10 k
L
L
Output power is very closely correlated with THD; see below
= 10k
= 10k
=1mA
-1mA
= 8
= 8
BTL
BTL
L
L
L
L
= 8 ,
= 8 ,
= 8 ,
= 8 ,
0.7 DBVDD
0.9 DBVDD
MIN
(SPKVDD/3.3)*1.5
(SPKVDD/3.3)*1.5
SPKVDD/3.3
SPKVDD/3.3
0.65*AVDD
0.9*AVDD
0.04
0.02
TBD
TBD
TYP
100
-68
1.0
-40
-74
1.0
-40
-84
90
90
80
69
98
52
56
15
PTD Rev 2.6 November 2005
0.3 DBVDD
0.1xDBVDD
MAX
3
WM8978
nV/ Hz
Vrms
Vrms
Vrms
UNIT
mA
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
pF
pA
%
%
%
%
V
V
V
V
V
V
9