NITROGEND2 - C-Media Electronics, Inc.

The Best USB Audio Single Chip for Stereo Digital

Adaptor Application

Nitrogen D2

16-Bit Stereo USB Audio Controller

(Dolby Digital Live and DTS Interactive Software Technology Bundle)

Datasheet

Version 1.02

C-MEDIA ELECTRONICS INC.

TEL: 886-2-8773-1100 FAX: 886-2-8773-2211

6F, 100, Sec. 4, Civil Boulevard, Taipei, Taiwan 106, R.O.C.

For detailed product information, please contact TUsales@cmedia.com.twUT

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 2 -

NOTICES

THIS DOCUMENT IS PROVIDED “AS IS” WITH NO WARRANTIES WHAT SO EVER,

INCLUDING ANY WARRANTY OF MERCHANT ABILITY, NONINFRINGEMENT, FITNESS

FOR ANY PARTICULAR PURPOSE, OR ANY WARRANTY OTHERWISE ARISING OUT

OF ANY PROPOSAL, DOCUMENT OR SAMPLE.

TRANSMITTED IN ANY FORM OR BY ANY MEANS, ELECTRONIC OR MECHANICAL,

INCLUDING INFORMATION STORAGE AND RETRIEVAL SYSTEMS, WITHOUT

PERMISSION IN WRITING FROM C-MEDIA ELECTRONICS, INC.

UCOPYRIGHT

button icons, images, audio clips, digital downloads, data compilations, and software, is

either the exclusive property of C-Media Electronics Inc., its affiliates (collectively,

"C-Media"), its content suppliers, or its licensors and protected by Republic of China and

international copyright laws.

UTRADEMARKS

C-Media, the C-Media Logo, Xear 3D, Xear 3D Logo and Speaker Shifter are trademarks of

C-Media Electronics Inc. in Republic of China and/or other countries. Dolby Digital and

dts are trademarks of Dolby Laboratories, Inc. and DTS Corporate. and All other brand,

logos and product names listed are trademarks or registered trademarks of their respective

holders and are hereby recognized as such.

*C-Media reserves the right to modify the specifications without further notice*

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 3 -

TABLE OF CONTENTS

1. DESCRIPTIONS AND OVERVIEW 5

2. FEATURES 6

3. PIN DESCRIPTIONS 8

3.1 PIN ASSIGNMENT BY PIN NUMBER 8

3.2 PIN-OUT DIAGRAM 8

3.3 PIN SIGNAL DESCRIPTIONS 9

4. BLOCK DIAGRAM 12

5. ORDERING INFORMATION 13

6. FUNCTION DESCRIPTIONS 14

6.1 USB INTERFACE 14

6.1.1 DEVICE DESCRIPTOR 14

6.1.2 CONFIGURATION DESCRIPTOR 15

6.1.3 USB AUDIO TOPOLOGY DIAGRAM 15

6.2 EEPROM (93C46) CONTENT FORMAT 16

6.3 HID FEATURE 17

6.3.1 WHAT’S HID 17

6.3.2 HID DESCRIPTOR 17

6.4 DYNAMIC RANGE CONTROL (DRC) 19

6.5 DOLBY DIGITAL LIVE TECHNOLOGY 20

6.5.1 DOLBY DIGITAL LIVE TECHNOLOGY 20

6.5.2 DIGITAL THEATER SYSTEM (DTS INTERACTIVE) 20

6.6 BENEFITS AND ADVANTAGE 21

7. ELECTRICAL CHARACTERISTICS 23

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 4 -

7.1 ABSOLUTE MAXIMUM RATING 23

7.2 OPERATION CONDITIONS 23

7.3 SPERKER IMPEDANCE VS. OUTPUT POWER (PER CHANNEL) 23

7.4 AUDIO PERFORMANCE 24

8. AUDIO PERFORMANCE CURVES 25

8.1 FREQUENCY RESPONSE (10K OHM LOADING) 25

8.1.1 FREQUENCY RESPONSE @ 44.1 KS/SEC 25

8.1.2 FREQUENCY RESPONSE @ 48 KS/SEC 25

8.2 PASSBAND RIPPLE (10K OHM LOADING) 26

8.2.1 PASSBAND RIPPLE @ 44.1 KS/SEC 26

8.2.2 PASSBAND RIPPLE @ 48 KS/SEC 26

9. REFERENCE APPLICATION CIRCUIT 27

10. REFERENCE 28

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 5 -

1. DESCRIPTIONS AND OVERVIEW

Nitrogen D2 is the world first USB audio chip that with Dolby Digital Live and dts Interactive

sounds technology supporting. This new chip design can provided more efficiency features

and high quality sound for portable USB audio products application. It is a highly integrated

single chip for USB stereo audio and SPDIF output application. Minimum external

components are needed for building an USB audio system, which makes Nitrogen D2 a

simple and very cost-effective solution.

Nitrogen D2 is design for all kind of PC base USB personal multi-media device products. It

is USB 2.0 full speed compatible and utilizes USB bus power for plug-and-play feature. Via

C-Media Xear 3D Sound USB audio driver, users can avail themselves of a much better

virtual 7.1 CH environment capable. For high-end multi-media application, this light and

portable personal audio device can easy to processing any sound source to Dolby Digital

AC-3 and dts raw data by real-time encoding function. The world first innovation software

function to grade up every PC system and output high quality digital sound effects for link

up with high-end home theater equipments like amplifier, DVD player or decoder etc.

This special feature is Dolby Digital Live function modules. As we know, Dolby Digital and

dts (Digital Theater System) are the world well-known sound technology brands and

generality using on consumer electronics. Therefore, if PC products need to be home

theater equipment or media center this would be key feature and selling point for product

development. These functions not only provide easy bridge to connect PCs and consumer

electronics but also adding value and upgrade sound quality to PC products. In the future,

PCs can put on Dolby Digital and dts logo on it and provide advanced sound quality to

end-user. All of modules were implemented by C-Media in software technology and anyone

can request these features by license from Dolby Lab. and DTS Corporate. through

C-Media.

Moreover, the innovation technology DRC feature was integrated on Nitrogen D2. This

Dynamic Range Control function can support high efficiency volume output to get loudness

sound effect similar D class amplifier capability. Vender can just using single c hip to saving

external amplifier component and getting a better listen experience when listen to a music

source with wide dynamic range.

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 6 -

For vender specific requests, customers can use an EEPROM to create vendor specific

VID / PID / Product String, and even special hardware configuration. More flexible and

customized design is possible with GPIO pin, which is accessible by USB vendor specific

request. Volume control VR input pin; a traditional speaker front panel design can be built.

Nitrogen D2 support USB standard HID Interface which provide Volume _up / Volume

_down / Playback mute Buttons and Rotary Encoder for pure digital volume control.

2. FEATURES

 USB 2.0 Full Speed Compatible and USB IF certification

 USB Audio Devices Class Specification Ver1.0 Compatible

 USB Bus Powered 500mA, without External Power Supply

 High performance 16-Bit Stereo, 48 / 44.1 KHz Sampling Rate for Audio Playback

 S/PDIF Output Interface

 Embedded USB Transceiver

 Embedded High Performance 16-Bit Audio DAC

 Embedded Digital Control Power Amplifier for Speaker Driving

 Support Power Amplifier Enable / Disable Control Pin

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 7 -

 Support Dynamic Range Control (DRC) Feature to Provide a Better Listen Experience

 Embedded Power-On-Reset Block

 Embedded 5V to 3.3V Regulator with Voltage Level Detector for Single 5V External

Power Supply

 Embedded Temperature Protection Circuit

 Embedded X2 Modulation for Higher Audio Quality

 Embedded Anti-Pop Circuit with Internal Feedback St ructure

 Single 12MHz Crystal Input with Embedded PLL

 Isochronous Transfer using Adaptive Synchronization with Internal PLL

 External EEPROM Interface for Vendor Specific VID / PID / Product String

 EEPROM Read / Write Function via Vendor Specific Request for Mass Production

Convenience

 Analog Volume Control Input with Simple External VR Circuit

 Digital Volume Control Input with Digital Rotary Encoder or Vol_up / Vol_dn /

Play_mute Bottoms

 Vol_up / Vol_dn / Play_mute Pins and Di

g

ital Rotary Encoder Interface

Support USB HID Devices Class Ver1.11 for Host Volume Control

Synchronization

 3.3V I/O with 5V Tolerance

 Dolby® Digital Audio Streaming via S/PDIF Output

 Supports USB Suspend / Resume Mode and Remote Wakeup with Digital Volume

Control Pins

 LED Indicator Pin During Playback

 1 GPIO pin for Application Specific Usage

 Dolby Digital Live Software Sound Technology Bundle

 Digital Theater System (DTS Interactive) Software Sound Technology Bundle

 USB Software Driver Compatible with Win 98SE / Win ME / Win 2000 / Win

XP

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 8 -

3. PIN DESCRIPTIONS

3.1 PIN ASSIGNMENT BY PIN NUMBER

Pin # Signal Name Pin # Signal Name Pin # Signal Name Pin # Signal Name

1 EESK 13 NC 25 AVDD 37 NC

2 DVDD5V 14 NC 26 AVDD 38 DRCEN

3 EECS 15 REGV 27 LOL 39 SPDIFO

4 EEDW 16 NC 28 LOL 40 PDSW

5 EEDR 17 USB_DP 29 LOL 41 PAEN

6 LEDO 18 NC 30 LOL 42 GPIO

7 MUTE 19 USB_DM 31 LOR 43 VOL_UP

8 DVDD5V 20 NC 32 LOR 44 VOL_DN

9 DVDD5V 21 DVSS 33 LOR 45 DVSS

10 VP 22 TEST 34 LOR 46 NC

11 VN 23 VREF 35 AVSS 47 XTAL_O

12 NC 24 VOLADJ 36 AVSS 48 XTAL_I

*Note: -NC- means No-Connect

3.2 PIN-OUT DIAGRAM

Nit rogen D2

EESK

DVDD5V

EECS

EEDW

EEDR

LEDO

MUTE

DVDD5V

VP

VN

NC

AVSS

LOR

LOL

AVDD

NC

REGV

NC

USB_DP

NC

USB_DM

NC

DVSS

TEST

VREF

VOL_ADJ

XTAL_I

XTAL_O

NC

DVSS

VOL_DN

VOL_UP

GPIO

PAEN

PDSW

SPDIFO

NC

1

13

25

37

12

24

36

48

DRC EN

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 9 -

3.3 PIN SIGNAL DESCRIPTIONS

Pin # Symbol Type Description

1 EESK

DO, 8mA, SR EEPROM Interface Clock

2 DVDD5V P 5V Power Supply for Digital Circuit

3 EECS

DO, 8mA, SR EEPROM Interface Chip Select

4 EEDW

DO, 8mA, SR EEPROM Interface Write to EEPROM

5 EEDR

DI, ST, PD,

5VT EEPROM Interface Read from EEPROM

6 LEDO

DO, 8mA, SR LED Indicator for Playback

7 MUTE

DI, ST, PU Mute Pin (HID Standard)

8 DVDD5V P 5V Power Supply

9 DVDD5V P 5V Power Supply

10 VP DI, ST, PU Digital Rotary Encoder Interface Pin A

11 VN DI, ST, PU Digital Rotary Encoder Interface Pin B

12 NC - No Connect

13 NC - No Connect

14 NC - No Connect

15 REGV AO Regulator output 3.3V

16 NC - No Connect

17 USB_DP AIO USB Data D+

18 NC - No Connect

19 USB_DM AIO USB Data D-

20 NC - No Connect

21 DVSS P Digital Ground

22 TEST DI, ST, PD Test Mode Select Pin, Pull-Down in normal Operation

23 VREF AO Connecting to External Decoupling Capacitor for

Embedded Band-gap Circuit; 2.25V Output

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 10 -

24 VOLADJ AI

Analog Volume Control Input from external VR circuit.

0 ~ 2.25V:+3dB / mute

3.5 ~ 5V: 0dB

25 AVDD P 5V Power Supply for Analog Circuit

26 AVDD P 5V Power Supply for Analog Circuit

27 LOL AO Line Out Left Channel

28 LOL AO Line Out Left Channel

29 LOL AO Line Out Left Channel

30 LOL AO Line Out Left Channel

31 LOR AO Line Out Right Channel

32 LOR AO Line Out Right Channel

33 LOR AO Line Out Right Channel

34 LOR AO Line Out Right Channel

35 AVSS P Analog Ground

36 AVSS P Analog Ground

37 NC - No Connect

38 DRCEN DI 1:DRC ON (default) 0:DRC Off

39 SPDIFO DO, 8mA, SR S/PDIF Data Output

40 PDSW DO, 8mA, SR

Power Down Switch Control Signal Output

1: Normal Mode

0: Power Down Mode (Suspend Mode)

41 PAEN DI, ST

Power Amplifier Control Input, Connect to a Switch or

Pull-High in Normal Operation.

H: Enable Power Amplifier (Normal Mode)

L: Disable Power Amplifier

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 11 -

42 GPIO DIO, 8mA, ST,

SR, PD GPIO Pin, Controlled via Vender Specific Command

43 VOL_UP DI, ST, PU Volume Up Pin (HID Standard)

44 VOL_DN DI, ST, PU Volume Down Pin (HID Standard)

45 DVSS P Digital Ground

46 NC - No Connect

47 XTAL_O AO Output Pin for 12MHz Oscillator

48 XTAL_I AI Input Pin for 12MHz Oscillator

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

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

P – Power Pin

SR – Slew Rate Control

ST – Schmitt Trigger

PD / PU – Pull Down / Pull Up

5VT – 5 Volt Tolerant (3.3V Pad)

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 12 -

4. BLOCK DIAGRAM

U SB I/F

HID Control I/F

FIFO

Crystal OSC

USB

Clock Gen Audio

Clock Gen

Pow er Supply

DAC

ADC

VOL

- 43.5~ +3dB

OP

EEPROM

I/F

DAC

VOL

- 43.5 ~ +3dB

OP

D-

D+

LOL

LOR

XTAL_I

XTAL_O

5V

REGV

(3.3V)

GND

PDSW

PAEN

VOL_UP

VOL_DN

VN

MUTE

VP

EEDR

EEDW

EESK

EECS

Bandgap VREF

VOLADJ

TEST

LEDO

GPIO

Dynamic

Range

Control

2x Over

Sampling

D igital Filter

SPDIFO

Block Diagram Of Nitrogen D2

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 13 -

5. ORDERING INFORMATION

Model

Number Package Operating Ambient

Temperature Supply Range

Nitrogen D2 48-Pin LQFP

7mm×7mm×1.4mm (Plastic) 0oC to +70oC DVdd = 5V,

AVdd = 5V

48-Lead Thin Plastic Quad Flatpack (LQFP)

Outline Dimensions *Dimensions shown in inches and (mm)

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 14 -

6. FUNCTION DESCRIPTIONS

6.1 USB INTERFACE

6.1.1 DEVICE DESCRIPTOR

Offset Field Size Value

(Hex) Description

0 bLength 1 12

Total 18 Bytes

1 bDescriptorType 1 01

Device Descriptor

2 bcdUSB 2 0110

USB 1.1 compliant.

4 bDeviceClass 1 00

5 bDeviceSubClass 1 00

6 bDeviceProtocol 1 00

7 bMaxPacketSize0 1 08

Endpoint Zero Size = 8 bytes

8 idVendor 2 0D8C

Vendor ID

10 idProduct 2 0104

Product ID

12 bcdDevice 2 0010

Device Release Number

14 iManufacturer 1 01

Index of string descriptor describing

manufacturer -> “C-Media INC.”

15 iProduct 1 02

Index of string descriptor describing

product -> "C-Media USB Audio "

16 iSerialNumber 1 00

Index of string descriptor describing the

device’s serial number

17 bNumConfigurations 1 01 Configurations number = 1

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 15 -

6.1.2 CONFIGURATION DESCRIPTOR

Offset Field Size Value

(Hex) Description

0 bLength 1 09

Total 9 Bytes

1 bDescriptorType 1 02

Configuration Descriptor

2 wTotalLength 2 008D

Total length of data returned for this

configuration.

4 bNumInterfaces 1 03

Number of interfaces supported by this

Configuration.

5 bConfigurationValue 1 01

6 iConfiguration 1 00

7 bmAttributes 1 80

Self-powered without Remote Wakeup

8 bMaxPower 2 FA

Maximum power consumption of the

USB. 0xFA=500 mA

6.1.3 USB AUDIO TOPOLOGY DIAGRAM

USB streaming

ID = 01 Feature Unit

(Volume) (Mute)

ID = 0D

Speaker

ID = 03

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 16 -

6.2 EEPROM (93C46) CONTENT FORMAT

Nitrogen D2 supports four-wire serial EEPROM interface. When an external serial

EEPROM is detected, Vendor ID, Product ID, and Product String reported within

Device Descriptor will be derived from the content of serial EEPROM. The setting

values of serial EEPROM is shown below:

Address Contents

00 0x434D (*Note1)

01 Vender ID

02 Product ID

03 String1, String0

04 String3, String2

05 String5, String4

06 String7, String6

07 String9, String8

08 String11, String10

09 String13, String12

10 String15, String14

11 String17, String16

12 String19, String18

13 String21, String20

14 String23, String22

15 Bit 0: DRC Enable / Disable

16~63 --

*Note: The first word of the EEPROM is a magic code. Only when it matches,

the IC will regard the serial EEPROM valid.

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 17 -

6.3 HID FEATURE

Nitrogen D2 provides HID feature with user setting to Volume-Up, Volume-Down,

Playback-Mute button pin, and the Digital-Rotary-Encoder for Volume Control is

reported to the host to synchronize host side setting.

6.3.1 WHAT’S HID

USB protocols can configure devices at startup or when they are plugged in at run

time. These devices are broken into various device classes. Each device class

defines the common behavior and protocols for devices that serve similar

functions. The HID (Human Interface Device) class is one of the device classes.

The HID class consists primarily of devices that are used by humans to control the

operation of computer systems. Typical examples of HID class devices include:

- Keyboards and pointing devices, for example: mouse, trackballs, and

joysticks.

- Front-panel controls, for example: knobs, switches, buttons, and sliders.

- Controls that might be found on devices such as VCR remote controls,

games or simulation devices, for example: data gloves, throttles, and

steering wheels.

- Devices that may not require human interaction but provide data in a

similar format to HID class devices, for example: bar-code readers,

thermometers, or voltmeters.

6.3.2 HID DESCRIPTOR

HID Interface Descriptor

Offset Field Size Value (Hex) Description

0 bLength 1 09 Size of this descriptor: 9 byte

1 bDescriptorType 1 04 INTERFACE descriptor type

2 bInterfaceNumber 1 02 Number of Interface

3 bAlternateSetting 1 00 alternate 0

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 18 -

Offset Field Size Value (Hex) Description

4 bNumEndpoints 1 01 Number of endpoints used by this

Interface: 1

5 bInterfaceClass 1 03 HID Interface Class

6 bInterfaceSubClass 1 00 No Subclass

7 bInterfaceProtocol 1 00 Must be set to 0

8 iInterface 1 00

Index of a string descriptor that

describes this interface.

HID Descriptor

Offset Field Size Value (Hex) Description

0 bLength 1 09 Total 9 Bytes

1 bDescriptorType 1 21 HID Descriptor Type

2 bcdHID 2 0100 HID class version 1.00

4 bCountryCode 1 00

5 bNumDescriptors 1 01

6 bDescriptorType 1 22 Report Descriptor

7 wDescriptorLength 2 002A Numeric expression that is the

total size of the optional descriptor

Interrupt IN Endpoint Descriptor

Offset Field Size Value (Hex) Description

0 bLength 1 07 Total 7 Bytes

1 bDescriptorType 1 05 ENDPOINT Descriptor Type

2 bEndpointAddress 1 81 IN Endpoint

Endpoint number = 3

3 bmAttributes 1 03 Interrupt endpoint type

4 wMaxPacketSize 2 0003 Maximum packet size: 4 bytes

6 bInterval 1 04 Interrupt Interval: 4ms

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 19 -

6.4 DYNAMIC RANGE CONTROL (DRC)

Nitrogen D2 include a new feature called Dynamic Range Control (DRC), and with a

default ON setting (Users can still turn it off within the Windows audio advance control

panel)

Dynamic range is defined as the difference, in decibels (dB), between the loudest and

quietest sounds in any particular piece of audio content. Classical music is a good

example, with ranges from piano (soft) to forte to FFF (for extremely loud). Movies also

typically have a wide dynamic range, which may cause you to have to turn the volume

up and down as scenes change. For example, when watching a movie at home, you

may be forced to turn up volume to hear the dialog in a quiet scene, and then quickly

turn it down again during a car chase scene that follows. In this way, there may be

times in a home theater environment when it would be useful to be able to control the

dynamic range.

With Dynamic Range Control enabled, the full dynamic range (A) of the program

is reduced (B).

+10dB

0dB

-10dB

-20dB

-30dB

-40dB

-50dB

-60dB

+20dB

Lower Levels Raised

Peaks Reduced

A

B

DRC

Peaks Reduced

Lower Levels Raised

Peaks Clipped

Lower Levels

hard to heard

A

B

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 20 -

6.5 DOLBY DIGITAL AND DTS SOUND TECHNOLOGY

6.5.1 DOLBY DIGITAL LIVE TECHNOLOGY

C-Media Xear 3D™ Sound Solution provides another state-of-the-art high quality audio

function--Dolby digital AC-3 encoder module. With this real-time software encoder, the

existing and future customers who are using C-Media USB audio solution and devices

can obtain this digital quality audio output by S/PDIF format much easier than before.

This function can output various 3D and environmental sound ef fects by high quality AC-3

encoding; in the meantime, it exhibits supreme efficiency—it takes only 7% of CPU

consumption from a Pentium 4 Processor.

A technology that can encode all the digital audio content on

PC into Dolby Digital stream in real-time. It can then be sent to

external decoder for playback. All path are digital and wiring is

simple.

6.5.2 DIGITAL THEATER SYSTEM (DTS interactive)

Besides Dolby, C-Media was also the world first PC audio provider whom can integrate

whole DTS Digital DSP technology in software module. Everyone knows that, DTS is the

famous of the world sound technology which guarantee high quality and performance.

DTS Interactive can take any content (WMA, MP3, CD, and more!) to transfer 5.1

multi-chances with real-time whenever play on line game, listen music, and watch VCD.

A real-time DTS encoder which takes any LPMC (2 channel or

more) and encodes it into DTS bit stream. The data transfer

format is 48 KHz at 1.5 mb/sec. Just using a single cable

connection to your DTS enabled surround sound system such

as, powered PC speakers, an A/V receiver or any other DTS

compatible surround sound system.

Better yet, the pure digital signal not only prevents the audio signal from distortion, but

also reduces the number of wires connected between PC and a HI-FI audio system. That

is to say, this breakthrough real-time AC-3 or DTS encoder can digitally transmit data

from PC to HI-FI system via a single RCA cable, instead of three pairs in an analog signal

case in the past.

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 21 -

6.6 BENEFITS AND ADVANTAGES

Uses a single digital connection

Transforms all PC audio signals into a Dolby and DTS Digital signal

Optimized for low-latency interactive applications

Provides realistic 5.1-channel surround sound effects during interactive video

game play

Advantages of this feature：

1.Getting higher quality audio signal output compared with any other SPDIF-Out solutions.

C-Media Xear 3D™ Plus DDL or DTS INTERACTIVE encoder sound solution can

directly process and transmit any PC sound source to digital AC-3 or DTS signal.

Digital-transmitted data processed by software driver can absolutely rule out the

characteristics influence of DAC quality. Therefore, users are able to get the best sound

quality.

2.General PC audio SPDIF-Out solution can only provide 2CH PCM data to external

amplifier. If users want to output high quality digital AC-3 or DTS INTERACTIVE

bit-stream, they have to rely on software DVD player, from which only DVD playback is

achievable. In that case, it will limit and impair the high quality multi-channel sound

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 22 -

enjoyment. C-Media DDL or DTS INTERACTIVE encoder solution not only retains the

above functions, but also provides other possible applications on PC audio. Xear 3D™

plus AC-3 or DTS encoder sound solution can process any type of sound sources, and

people are able to obtain 7.1CH output by using virtual SPEAKER SHIFTER™ to create

optimized personal listening environment.

3.In terms of 3D gaming, C-Media Xear 3D™ sound engine for Dolby Digital Live or DTS

INTERACTIVE encoder are far better than Window DirectX 3D sound emulator, in that it

is powered by sophisticated HRTF (Head Related Transfer Function) library, supporting

environmental ef fects (EAX 1.0 & 2.0 comp atible) to create highly immersive 3D gaming

experience. All interactive sound effects of 3D game can real-time encoding to AC-3 or

DTS INTERACTIVE bit-stream and getting high quality digital signal to external decoder

and speakers for enjoyment.

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 23 -

7. ELECTRICAL CHARACTERISTICS

7.1 ABSOLUTE MAXIMUM RATING

Symbol Parameter Value Unit

Dvmin Min Digital Supply Voltage – 0.3 V

Dvmax Max Digital Supply Voltage + 6 V

Avmin Min Analog Supply Voltage – 0.3 V

Avmax Max Analog Supply Voltage + 6 V

Dvinout Voltage on any Digital Input or Output Pin –0.3 to +5.5 V

A vinout Volt age on any Analog Input or Output Pin –0.3 to +5.5 V

TBstgB Storage Temperature Range -40 to +125 P

0

PC

ESD (HBM) ESD Human Body Mode 2000 V

ESD (MM) ESD Machine Mode 200 V

Latchup Latch Up Test 200 mA

7.2 OPERATION CONDITIONS

Min Typ Max Unit

Analog Supply Voltage 4.5 5.0 5.5 V

Digital Supply Voltage 4.5 5.0 5.5 V

Total Power Consumption - - 500 mA

Suspend Mode Power Consumption - - 320 uA

Operating ambient temperature 0 - 70 P

o

PC

7.3 SPERKER IMPEDANCE VS. OUTPUT POWER (PER CHANNEL)

Loading (Ohm)

Items 4 Ohm 8 Ohm 32 Ohm 10K Ohm

Vpp 3.14 3.4 3.635 3.722

Vrms 1.11 1.202 1.285 1.316

W(rms/sin wave) 308 mW 181 mW 52 mW 0.17 mW

W(rms/square wave) 616 mW 361 mW 103 mW 0.35 mW

W(PMPO) 2460 mW 1450 mW 410 mW 1 mW

*Note1: Test Condition @ 25oC, 5 Volt +- 10%, 1KHz Sin Wave

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 24 -

*Note2: Typical Output with THD+N < 1%; Maxi mal Output with THD+N < 10%

7.4 AUDIO PERFORMANCE

Min Typ Max Unit

Resolution -- 16 -- Bits

Frequency response @ 48KHz 20 -- 20K Hz

Frequency Response @ 44.1KHz 20 -- 20K Hz

Passband Ripple @ 48 KHz 40 -- 9.6K Hz

Passband Ripple @ 44.1 KHz 40 -- 8.8K Hz

DAC (10K Ohm Loading)

SNR -- 97.75 -- dB

Dynamic Range -- 96.27 -- dB

THD + N -- -67.97 -- dB

Output Voltage (rms) - 1.316 - Vrms

DAC (32 Ohm Loading)

SNR -- 97.68 -- dB

Dynamic Range -- 95.99 -- dB

THD + N -- -57.82 -- dB

Output Voltage (rms) - 1.285 - Vrms

DAC (8 Ohm Loading)

SNR -- 97.67 -- dB

Dynamic Range -- 96.03 -- dB

THD + N -- -53.28 -- dB

Output Voltage (rms) - 1.202 - Vrms

DAC (4 Ohm Loading)

SNR -- 97.45 -- dB

Dynamic Range -- 95.89 -- dB

THD + N -- -52.76 -- dB

Output Voltage (rms) - 1.11 - Vrms

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 25 -

8. AUDIO PERFORMANCE CURVES

8.1 FREQUENCY RESPONSE (10K OHM LOADING)

8.1.1 FREQUENCY RESPONSE @ 44.1 KS/SEC

C-MEDIA 05/31/05 14 :10:3 3Digital Playback (PC -D-A) for Line Output Frequency

Response

WL-Multitone-44k.at2c

ColorSweep Trace Line Style Thick Data Axis Comment

1 1 Cyan Solid 3 Fasttest.Ch.1 Ampl!Normalize Left

1 2 Yellow Solid 3 Fasttest.Ch.2 Ampl!Normalize Left

-6

+1

-5

-4

-3

-2

-1

+0

d

B

r

A

20 10k50 100 200 500 1k 2k 5k

Hz

8.1.2 FREQUENCY RESPONSE @ 48 KS/SEC

C-MEDIA 05/31/05 14:07:22Digital Playback (P C-D-A) for Line O utput Frequency

Response

WL-Multitone-48k.at2c

ColorSweep Trace Line Style Thick Data Axis Comment

1 1 Cyan Solid 3 Fasttest.Ch.1 Ampl!Normalize Left

1 2 Yellow Solid 3 Fasttest.Ch.2 Ampl!Normalize Left

-6

+1

-5

-4

-3

-2

-1

+0

d

B

r

A

30 10k50 100 200 500 1k 2k 5k

Hz

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 26 -

8.2 PASSBAND RIPPLE (10K OHM LOADING)

8.2.1 PASSBAND RIPPLE @ 44.1 KS/SEC

C-MEDIA 05/31/05 14:11:07Digital Playback (PC-D-A) for Line Output Passband

Rip ple @44.1ks/sec

WL-PassbandRipple-M44k.at2c

ColorSweep Trace L ine Style T hick Data Axi s Comment

1 1 Cyan Soli d 3 Fasttest.Ch.1 Ampl!Normali ze Left

1 2 Yell o w Solid 3 Fasttest.Ch.2 Ampl!Normali ze Left

-0.4

+0.4

-0.2

-0

+0.2

d

B

40 8k50 100 200 500 1k 2k 5k

Hz

8.2.2 PASSBAND RIPPLE @ 48 KS/SEC

C-MEDIA 05/31/05 14:09:08Digital Playback (PC-D-A) for Line Output Passband

Ripple @ 48ks/sec

WL-PassbandRipple-M48k.at2c

ColorSweep T r ac e Line Style T hick Data Axis Comment

1 1 Cyan Solid 3 Fasttest.Ch.1 A mpl!Normalize Left

1 2 Yellow Solid 3 F ast test .Ch.2 Ampl! Normalize Lef t

-0.4

+0.4

-0.2

-0

+0.2

d

B

40 9k50 100 200 500 1k 2k 5k

Hz

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 27 -

9. REFERENCE APPLICATION CIRCUIT

Nitrogen D2

USB Audio With Dolby Digital Live and DTS Interactive Solution

Date: 09/25/2005 Version: 1.02

- 28 -

10. Reference

♦ Universal Serial Bus Specification, Version 2.0

♦ Universal Serial Bus Device Class Definition for Audio Devices, Version 1.0.

♦ Universal Serial Bus Device Class Definition for Human Interface Devices (HID),

Version 1.11

♦ Dolby Digital Live and dts Interactive function specification

－End of Specifications－

C-MEDIA ELECTRONICS INC.

6F., 100, Sec. 4, Civil Boulevard, Taipei, Taiwan 106 R.O.C.

TEL:886-2-8773-1100

FAX:886-2-8773-2211

E-mail：TUsales@cmedia.com.twUT URL：TUhttp://www.cmedia.com.twUT