WM8774
24-bit, 192kHz 8-Channel Input Stereo Codec
WOLFSON MICROELECTRONICS LTD
w :: www.wolfsonmicro.com
Product Preview, June 2002, Rev 1.0
Copyright
2002 Wolfson Microelectronics Ltd.
DESCRIPTION
The WM8774 is a high performance, stereo audio codec
with an 8 channel input selector. The WM8774 is ideal for
surround sound processing applications for home hi-fi,
automotive and other audio visual equipment.
A stereo 24-bit multi-bit sigma delta ADC is used with an
eight stereo channel input selector. Each channel has
analogue domain mute and programmable gain control.
Digital audio output word lengths from 16-32 bits and
sampling rates from 8kHz to 96kHz are supported.
A stereo 24-bit multi-bit sigma delta DAC is used with
oversampling digital interpolation filters. Digital audio input
word lengths from 16-32 bits and sampling rates from 8kHz
to 192kHz are supported. Each DAC channel has
independent analogue volume and mute control, with a set
of input multiplexors allowing selection of an external
analogue input into these volume controls.
The audio data interface supports I
2
S, left justified, right
justified and DSP digital audio formats.
The device is controlled via a 3 wire serial interface. The
interface provides access to all features including channel
selection, volume controls, mutes, de-emphasis and power
management facilities. The device is available in a 64-pin
TQFP package.
FEATURES
Audio
Performance
-
106dB SNR (`A' weighted @ 48kHz) DAC
-
101dB SNR (`A' weighted @ 48kHz) ADC
DAC Sampling Frequency: 8kHz 192kHz
ADC Sampling Frequency: 8kHz 96kHz
3-Wire SPI Compatible Serial Control Interface
Master or Slave Clocking Mode
Programmable Audio Data Interface Modes
-
I
2
S, Left, Right Justified or DSP
-
16/20/24/32 bit Word Lengths
Stereo DAC with independent analogue and digital volume
controls
Analogue Bypass Path Feature
Selectable AUX input to the volume controls
Eight stereo ADC inputs with analogue gain adjust from
+19dB to 12dB in 1dB steps
2.7V to 5.5V Analogue, 2.7V to 3.6V Digital supply
Operation
5V tolerant digital inputs
APPLICATIONS
BLOCK DIAGRAM
Surround Sound AV Processors and Hi-Fi systems
Automotive
Audio
VOUTL
VOUTR
STEREO
ADC
AGN
D
AVD
D
VMID
AD
C
AUDIO INTERFACE
AND
DIGITAL FILTERS
AD
C
L
R
C
BC
LK
DA
C
L
RC
DI
N
DO
U
T
STEREO
DAC
I
N
P
U
T S
O
U
RCE
S
E
LE
CT
O
R
AIN2R
AIN3L
AIN3R
AIN4L
AIN4R
AIN5L
AIN5R
AIN6L
AIN6R
RECL
RECR
AINOPR
AINOPL
AIN
V
GR
AIN
V
GL
RE
F
A
DC
D
A
C
R
EF
P1
D
A
CR
E
F
N2
DV
DD
DG
ND
CONTROL INTERFACE
AU
X
L
AU
XR
DI
CE
CL
R
E
SET
B
MC
LK
AIN2L
AIN1R
AIN1L
AIN7L
AIN7R
AIN8L
AIN8R
WM8774
ZF
L
A
G
L
ZF
L
A
G
R
MUTE
LOW
PASS
FILTERS
GR
1
GR
2
AGN
D
2
A
V
DD2
VMID
D
A
C
WM8774
Product Preview
PP Rev 1.0 June 2002
2
PIN CONFIGURATION
ORDERING INFORMATION
DEVICE TEMP.
RANGE
PACKAGE
WM8774IFT/V
-40 to +85
o
C 64-pin
TQFP
AV
DD1
V
M
I
DADC
AG
ND1
AU
X
L
AI
NO
P
R
AI
NV
G
L
AI
NV
G
R
RE
C
L
RE
CR
AIN1L
AIN4L
AIN3R
AIN3L
AIN2R
AIN2L
AIN1R
AIN4R
AIN5L
AIN6L
R
ESET
B
BC
L
K
MCLK
CL
DI
CE
NC
NC
NC
DACLRC
ADCLRC
NC
NC
NC
DACREFP2
NC
NC
GR2
NC
VMIDDAC
1
9
8
7
6
5
4
3
2
11
10
21 22 23 24 25 26 27
18 19 20
41
40
39
38
37
36
43
42
64 63 62 61 60 59 58
17
57 56 55 54
35
34
33
AI
NO
P
L
AIN5R
RE
FADC
ZFL
A
G
L
ZFL
A
G
R
DV
DD
DO
U
T
DI
N
53 52 51 50 49
NC
NC
NC
NC
AU
X
R
DACREFP1
AVDD2
VOUTL
VOUTR
AIN6R
AIN7L
AIN7R
AIN8R
14
13
12
16
15
AIN8L
GR1
28 29 30 31 32
46
45
44
48
47
AGND2
DGND
Product Preview
WM8774
PP Rev 1.0 June 2002
3
PIN DESCRIPTION
PIN NAME TYPE
DESCRIPTION
1 AIN1L
Analogue
Input
Channel 1 left input multiplexor virtual ground
2 AIN1R
Analogue
Input
Channel 1 right input multiplexor virtual ground
3 AIN2L
Analogue
Input
Channel 2 left input multiplexor virtual ground
4 AIN2R
Analogue
Input
Channel 2 right input multiplexor virtual ground
5 AIN3L
Analogue
Input
Channel 3 left input multiplexor virtual ground
6 AIN3R
Analogue
Input
Channel 3 right input multiplexor virtual ground
7 AIN4L
Analogue
Input
Channel 4 left input multiplexor virtual ground
8 AIN4R
Analogue
Input
Channel 4 right input multiplexor virtual ground
9 AIN5L
Analogue
Input
Channel 5 left input multiplexor virtual ground
10 AIN5R
Analogue
Input
Channel 5 right input multiplexor virtual ground
11 AIN6L
Analogue
Input
Channel 6 left input multiplexor virtual ground
12 AIN6R
Analogue
Input
Channel 6 right input multiplexor virtual ground
13 AIN7L
Analogue
Input
Channel 7 left input multiplexor virtual ground
14 AIN7R
Analogue
Input
Channel 7 right input multiplexor virtual ground
15 AIN8L
Analogue
Input
Channel 8 left input multiplexor virtual ground
16 AIN8R
Analogue
Input
Channel 8 right input multiplexor virtual ground
17 AINOPL
Analogue
Output
Left channel multiplexor output
18 AINVGL
Analogue
Input
Left channel multiplexor virtual ground
19 AINVGR
Analogue
Input
Right channel multiplexor virtual ground
20 AINOPR
Analogue
Output
Right channel multiplexor output
21 RECL
Analogue
Output
Left channel input mux select output
22 RECR
Analogue
Output
Right channel input mux select output
23 REFADC
Analogue
Output
ADC reference buffer decoupling pin; 10uF external decoupling
24 VMIDADC
Analogue
Output
ADC midrail divider decoupling pin; 10uF external decoupling
25 AGND1 Supply
Analogue negative supply and substrate connection
26 AVDD1 Supply
Analogue positive supply
27 AUXL
Analogue
input
Multiplexor channel left virtual ground input
28 AUXR
Analogue
input
3.1 Multiplexor channel right virtual ground input
29
NC
No connection
30
NC
No connection
31
NC
No connection
32
NC
No connection
33 AVDD2 Supply
Analogue positive supply
34 VOUTL
Analogue
output
DAC channel 1 left output
35 VOUTR
Analogue
output
DAC channel 1 right output
36 DACREFP1 Supply
DAC positive reference supply
37
NC
No connection
38 GR1 Supply
DAC ground reference
39
NC
No connection
40 VMIDDAC
Analogue
output
DAC midrail decoupling pin ; 10uF external decoupling
41
NC
No connection
42 GR2 Supply
DAC ground reference
43
NC
No connection
44 DACREFP2 Supply
DAC positive reference supply
45
NC
No connection
46
NC
No connection
47 AGND2 Supply
Analogue negative supply and substrate connection
48 DGND Supply
Digital negative supply
49 DVDD Supply
Digital positive supply
WM8774
Product Preview
PP Rev 1.0 June 2002
4
PIN NAME TYPE
DESCRIPTION
50 ZFLAGL
Digital
output
DAC Zero Flag output
51 ZFLAGR
Digital
output
DAC Zero Flag output
52 DOUT
Digital
output
ADC data output
53 DIN
Digital
Input
DAC channel 1 data input
54
NC
No connection
55
NC
No connection
56
NC
No connection
57 DACLRC
Digital
input/output
DAC left/right word clock
58 ADCLRC
Digital
input/output
ADC left/right word clock
59 BCLK
Digital
input/output
ADC and DAC audio interface bit clock
60 MCLK
Digital
input
Master DAC and ADC clock; 256, 384, 512 or 768fs (fs = word clock
frequency)
61 CL
Digital
input
Serial interface clock (5V tolerant)
62 DI
Digital
input
Serial interface data (5V tolerant)
63
CE
Digital input
Serial interface Latch signal (5V tolerant)
64 RESETB
Digital
input
Device reset input (mutes DAC outputs, resets gain stages to 0dB)
(5V tolerant)
Note : Digital input pins have Schmitt trigger input buffers and are 5V tolerant.
Product Preview
WM8774
PP Rev 1.0 June 2002
5
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at
or beyond these limits. Device functional operating limits and guaranteed performance specifications are given under Electrical
Characteristics at the test conditions specified.
ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore generically susceptible
to damage from excessive static voltages. Proper ESD precautions must be taken during handling and storage
of this device.
CONDITION
MIN MAX
Digital supply voltage
-0.3V +3.63V
Analogue supply voltage
-0.3V +7V
Voltage range digital inputs (DI, CL, CE & RESETB) DGND
-0.3V
+7V
Voltage range digital inputs (MCLK, DIN[3:0], ADCLRC, DACLRC &
BCLK)
DGND -0.3V
DVDD + 0.3V
Voltage range analogue inputs
AGND -0.3V
AVDD +0.3V
Master Clock Frequency
37MHz
Operating temperature range, T
A
-40
C +85
C
Storage temperature
-65
C +150
C
Package body temperature (soldering 10 seconds)
+240
C
Package body temperature (soldering 2 minutes)
+183
C
Notes:
1.
Analogue and digital grounds must always be within 0.3V of each other.
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