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TYPICAL CONNECTIONS

AGND

VINR-

VINR+

VCC1

AGND

AGND

AGND

AGND

VCC2

VINL-

VINL+

1

2

3

4

PCM4220PFB

100nFto1 F

m

LeftChannel

AnalogInput

+4.0V

100nF

+

100 F

m

FromHost,Logic,

orManualControls

5

6

7

8

9

12

13

14

15

16

17

18

19

20

21

22

23

24

AGND

VCOML

REFGNDL

VREFL

PCMEN

HPFDR

HPFDL

FS0

FS1

DF

DGND

DGND

DGND

100 F

m

+

100nF

100nF

+

100 F

m

10

11

RightChannel

AnalogInput

VCOMR

REFGNDR

VREFR

DGND

FMT0

FMT1

OWL0

OWL1

DGND

S/M

OVFR

48

47

46

45

FromHost,Logic,

orManualControls

ToHostand/orClippingIndicators

FromHostorMasterReset

FromAudioMasterClockSource

Audio

DSPorHost

44

43

42

41

40

37

36

35

34

33

32

31

30

29

28

27

26

25

OVFL

RST

MCKI

LRCK

BCK

DATA

VDD

DGND

NC

NC

NC

SUB0

SUB1

100nF

+3.3V

+

100 F

m

39

38

100nF

+

100 F

m

100nFto1 F

m

RequiredonlyforTDMdataformats.

Thesepinsareignoredforallotherformats.

INPUT BUFFER CIRCUITS

PCM4220

SBAS407A – DECEMBER 2006 – REVISED MAY 2007

Figure 44 provides a typical connection diagram for the PCM4220. Recommended power-supply bypass and

reference filter capacitors are shown. These components should be located as close to the corresponding

PCM4220 package pins as physically possible. Larger power-supply bypass capacitors may be placed on the

bottom side of the printed circuit board (PCB). However, reference decoupling capacitors should be located on

the top side of the PCB to avoid issues with added via inductance.

As Figure 44 illustrates, the audio host device may be a digital signal processor (DSP), digital audio interface

transmitter (DIT), or a programmable logic device.

Figure 44. Typical Connections for PCM and DSD Output Modes

The PCM4220 is typically preceded in an application by an input buffer or preamplifier circuit. The input circuit is

required to perform anti-aliasing filtering, in addition to application-specific analog gain scaling, limiting, or

processing that may be needed. At a minimum, first-order, low-pass anti-aliasing filtering is necessary. The input

buffer must be able to perform the input filtering requirement, in addition to driving the switched-capacitor inputs

of the PCM4220 device. The buffer must have adequate bandwidth, slew rate, settling time, and output drive

capability to perform these tasks.

Figure 45 illustrates the input buffer/filter circuit utilized on the PCM4222EVM evaluation module, where the

PCM4222 analog input section is identical to the PCM4220. This circuit has been optimized for measurement

purposes, so that it does not degrade the dynamic characteristics of the PCM4220. The resistors are primarily

0.1% metal film. The 40.2

Ω resistor is 1% tolerance thick film. The 1nF and 2.7nF capacitors may be either PPS

24

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