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2 functional changes, An259, Cs4382a – Cirrus Logic AN259 User Manual

Page 3: Cs4382

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AN259

AN259REV2

3

Location or function changes as denoted in Figure 1 are as follows:

The CS4385 does not support the simultaneous synchronous sample rate function of the CS4382. Pins 10
and 12 are now Test inputs.

Pins which require changes to external components or voltages as denoted in Figure 2 are as follows:

Pin 4 (VD) requires 2.5 V for recommended operation. The CS4382 used either 3.3 V or 5 V, which, if left
unchanged, would damage the CS4382A.

Pin 22 (MUTEC234) and pin 41 (MUTEC1) require an additional pull-up or down in order to mute during
reset. While reset is asserted these pins are high impedance and will not drive the mute circuitry. It is
recommended that the pull-up/down resistance properly biases the off-chip mute circuit into muting.

Pins 23 - 30, 33 - 40 (AOUTs) have a new recommended filter circuit. This filter uses the same filter topology
as the CS4382. The component values have been changed to account for the extra output level from the
CS4382A and still provide 2 Vrms on the output. A general optimization was also made in order to reduce
the thermal noise contribution of the resistances (using smaller resistances where possible). Please refer to
the CS4382A datasheet for details on the new recommended filter.

2.1.2

Functional changes

-

With the addition of the non-decimating DSD processor mode comes the added benefits of
matched PCM and DSD output levels and an on chip 50 kHz filter.

-

The CS4382A uses a new multi-bit Delta-Sigma modulator core with mis-match shaping which al-
lows for lower over-all out-of-band noise and improved audio quality.

-

The CS4382A gained new digital filters with improved stop-band performance and lower latency.

-

The full scale differential output voltage has increased which needs to be accounted for in the an-

SDI

N

3

GND

AOUTB2-

AOUTA3+

AOUTB3-

AOUTB2+

VA

AOUTA3-

AOUTB3+

6

2

4

8

10

1

3

5

7

9

11

12

13 14 15 16 17 18 19 20 21 22 23 24

31

35

33

29

27

36

34

32

30

28

26

25

48 47 46 45 44 43 42 41 40 39 38 37

MCLK

DSDB1

VD

SDIN1

LRCK2

DSDA2

DSDA1

GND

SCLK1

SDIN2

SCLK2

LRCK1(DSD_EN)

M3

(D

SD_

S

CL

K)

DSDB3

DSDA3

DS

DA4

CS4382

DS

DB4

VL

S

SD

IN

4

M2

(S

CL

/CCL

K)

M

1

(SDA/CDIN)

VL

C

RS

T

FILT+

VQ

MUTEC2

3

4

M0(

A

D

0

/C

S

)

AOUTA2+

AOUTA2-

AO

U

T

B

1

+

AO

UT

B1

-

AO

UT

A1

-

AO

U

T

A1+

DS

DB2

MUTE

C1

AOUTA4-

AOUTA4+

AO

U

T

B4+

AO

U

T

B

4

-

= denotes location or function changes

when trasitioning to CS4382A

Figure 1. CS4382 pinout

SD

IN

3

GND

AOUTB2-

AOUTA3+

AOUTB3-

AOUTB2+

VA

AOUTA3-

AOUTB3+

6

2

4

8

10

1

3

5

7

9

11

12

13 14 15 16 17 18 19 20 21 22 23 24

31

35

33

29

27

36

34

32

30

28

26

25

48 47 46 45 44 43 42 41 40 39 38 37

MCLK

DSDB1

VD

SDIN1

TST

DSDA2

DSDA1

GND

SCLK1

SDIN2

TST

LRCK1(DSD_EN)

M3(DSD_SCLK)

DS

DB

3

DS

D

A

3

DSDA4

CS4382A

DSDB4

VLS

SD

IN

4

M2

(S

C

L

/C

CL

K

)

M1(

S

D

A

/CDI

N)

VLC

RST

FI

LT

+

VQ

MUT

E

C2

3

4

M0(AD

0

/C

S

)

AOUTA2+

AOUTA2-

AO

U

T

B1+

AOUT

B1-

AO

U

T

A1-

AOUTA1+

DSDB2

MUT

E

C

1

AOUTA4-

AOUTA4+

AOUTB4+

AO

UT

B

4

-

= denotes pins which require changes

to components or voltages

Figure 2. CS4382A pinout