WM8740

Production Data

w

PD, Rev 4.4, April 2010

24

APPLICATIONS INFORMATION

RECOMMENDED EXTERNAL COMPONENTS

28

DVDD

DGND

ML/I2S

AGND

AVDDL

AVDD

11

VMIDR

1

0

C

9

AGND

8

7

Software I/F or

Hardware Control

WM8740

Notes: 1.

AGND and DGND should be connected as close to the WM8740 as possible.

2. C

2

to

,

1

should be positioned as close to the WM8740 as possible.

3.

Capacitor type used can have a big effect on device performance. It is

recommended that capacitors with very low ESR are used and that ceramics are

either NPO or COG type material to achieve best performance from the WM8740.

AVDDR

AGNDR

AGNDL

C

3

C

4

C

5

C

6

AGND

C

2

DVDD

C

1

27

MC/DM1

26

MD/DM0

23

CSB/IWO

22

RSTB

4

MODE8X

6

DIFFHW

21

ZERO

AVDD

AVDD

R

1

18

VMIDL

2

1

LRCIN

2

DIN

3

BCKIN

5

SCLK

Audio Serial Data I/F

System Clock Input

DGND

+

+

+

+

15

9

20

14

10

19

24

MODE

25

MUTEB

VOUTRN

VOUTRP

-

-

+

+

13

12

LEFT OUTPUT DATA

RIGHT OUTPUT DATA

VOUTLP

17

VOUTLN

16

R

2

R

2

Figure 25 External Components Diagram

RECOMMENDED EXTERNAL COMPONENTS VALUES

COMPONENT

REFERENCE

SUGGESTED

VALUE

DESCRIPTION

C1 and C6

10

μF

De-coupling for DVDD and AVDD.

C2 to C5

0.1

μF

De-coupling for DVDD and AVDD.

C7 and C8

10

μF

Output AC coupling caps to remove VMID DC level from outputs.

C9 and C11

0.1

μF

Reference de-coupling capacitors for VMIDR and VMIDL.

C10 and C12

10

μF

R1

10k

Ω

Resistor to AVDD for open drain output operation.

R2

51

Ω

Source termination resistors.

Table 21 External Components Description