C371347_139780418F8DFE40697A24CD62AD2CE5.pdf - 第8页

CM108B

USB Audio Single Chip

Datasheet Revision: 1.11 www.cmedia.com.tw

4.3 Pin signal descriptions

Pin #

Symbol

Type

Description

1

SPDIFO

DO, 4mA, SR

SPDIF output

2

DR

DI, 8mA, PD, 5VT

EEPROM interface data read from EEPROM

3

DW

DO, 4mA, SR

EEPROM interface data write to EEPROM

4

SK

DO, 4mA, SR

EEPROM interface clock

5

CS

DO, 4mA, SR

EEPROM interface chip select

6

MUTER

DI, ST, PU

Mute recording (edge trigger with de-bouncing)

7

PWRSEL

DI, ST, PU

Chip power select pin:

H: push up to 3.3V, L: push down to ground

Speaker mode – H: 100mA self-powered, L: 500mA Bus-powered

Headset mode – H: 100mA Bus-powered, L: 500mA Bus-powered

8

DREG18

P

1.8V Regulator Output for Digital Core

9

DREG33

P

3.3V Regulator Output for Digital I/O (driving current 40mA)

10

MODE

DI, ST, PD

Operating mode selection:

H: push up to 3.3V, L: pull down to ground

H: speaker mode - playback only

L: headset mode - playback & recording

11

N.C.

12

LEDO

DO, SR, 4mA

LED operation light: output H for power on, toggling for data transmit

13

GPIO3

DIO, 8mA, PD, 5VT

GPIO pin

14

DVSS

P

Digital ground

15

GPIO4

DIO, 8mA, PD, 5VT

GPIO pin

16

SDIN

DIO, 8mA, PD, 5VT

ADC I2S data input

17

ADSCLK

DO, 2mA, SR

ADC I2S serial clock

18

MUTEP

DI, ST, PU

Mute playback (edge trigger with de-bouncing)

19

ADLRCK

DO, 2mA, SR

ADC I2S left/right clock

20

ADMCLK

DO, 2mA, SR

11.2896MHz output for 44.1KHz sampled data and

12.288MHz output for 48KHz sampled data

21

LEDR

DO, SR, 4mA

LED for mute recording indicator, output H when recording is muted

22

ADSEL

DI, ST, PD

ADC input source select pin

H: use external (via I2S) ADC

L: use internal ADC

(H: push up to 3.3V, L: push down to ground)

23

TEST

DI, ST, PD

Test mode select pin,

H: test mode

L: normal operation

(H: push up to 3.3V, L: push down to ground)

24

AVSS

P

Analog ground

25

VBIAS

AO

Microphone bias voltage supply (3V), with a small driving capability

26

VREF

AO

Connecting to external decoupling capacitor for embedded bandgap

circuit, 1.75V output

27

MICIN

AI

Microphone input, input impedance is 10k Ohm

28

N.C.

29

AVDD

P

5V analog power for analog circuit

30

LOL

AO

Line out: left channel

31

LOBS

AO

DC 1.75V output for line out bias

32

LOR

AO

Line out: right channel

33

AVSS

P

Analog ground

34

AVDD

P

5V power supply for analog circuit

35

DVDD

P

5V power supply for internal regulator

36

DVSS

P

Digital ground

37

AREG36

P

3.6V analog power for analog circuit

CM108B

USB Audio Single Chip

Datasheet Revision: 1.11 www.cmedia.com.tw

38

MSEL

DI, ST, PU

Mixer enable select:

H: push up to 3.3V, L: push down to ground

H: with mixer/AA-path enabled (with default mute)

L: without mixer/AA-path disabled

USB descriptors will also be changed accordingly

39

VOLUP

DI, ST, PU

Volume up (edge trigger with de-bouncing)

40

PDSW

DO, 4mA , OD

Power down switch control signal (for PMOS polarity)

0: normal operation

1: power down mode (suspend mode)

41

USBDP

AIO

USB Data D+

42

USBDM

AIO

USB Data D-

43

GPIO1

DIO, 8mA, PD, 5VT

GPIO pin

44

SDOUT

DO, 2mA, SR

DAC I2S data output

45

DAMCLK

DO, 2mA, SR

11.2896 MHz output for 44.1KHz sampled data and

12.288 MHz output for 48KHz sampled data

46

DALRCK

DO, 2mA, SR

DAC I2S left/right clock

47

DASCLK

DO, 2mA, SR

DAC I2S serial clock

48

VOLDN

DI, ST, PU

Volume down (edge trigger with de-bouncing)

NoteU: DI / DO / DIO – Digital Input / Output / Bi-Directional Pad

AI / AO / AIO – Analog Input / Output / Bi-Directional Pad

SR – Slew Rate Control

ST – Schmitt Trigger

PD / PU – Pull Down / Pull Up

5VT – 5 Volt Tolerant (3.3V Pad)

OD – Open Drain

P – Power Supply Pin

CM108B

USB Audio Single Chip

Datasheet Revision: 1.11 www.cmedia.com.tw

5 Block diagram

Regulator

5->3.6, 3.3 & 1.8

USB

Interface

USB TRX

EEPROM

Interface

RF

PLL

ISO Out

Processing

ISO In

Processing

12M

48M

SPI

USB

DW

DR

SK

CS

USBDP

USBDN

16 bit

DAC

16 bit

DAC

12dB/22dB

Booster

23 ~ -22dB

8 ~ -22dB

0 ~ -45dB

SRAM

bandgap

VREF

(1.75V)

VREF

VBIAS

(3V)

USB Control

Interface Logics

AREG36

VOLUP

VOLDN

MUTER

MUTEP

LEDO

LEDR

PWRSEL

MODE

MSEL

PDSW

3.6V

LOR

LOL

MICI

N

DREG33

3.3V 1.8V

VREF

LOBS

16 bit

ADC

DREG18

GPIOs

DASCLK/ADSCLK

DALRCK/ADLRCK

DAMCLK/ADMCLK

SDOUT/SDIN

I2S Out/In

CM108B Block Diagram