The Best USB Audio Single Chip for
Stereo Digital Control Speakers Application
CM103+
16-Bit Stereo USB Audio Controller
Datasheet
Version 1.01
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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 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.
ALL RIGHTS RESERVED. NO PART OF THIS DOCUMENT MAY BE REP RODUCED OR
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
Copyright (c) 2005-2007 C-Media Electronics Inc.
All rights reserved. All content included on this document, such as text, graphics, logos,
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, Speaker Shifter, Smart Jack, and
Smart Audio Jack are trademarks of C-Media Electronics Inc. in Republic of China and/or
other countries. All other brand 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*
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 3 -
TABLE OF CONTENTS
1. DESCRIPTIONS AND OVERVIEW 5
2. FEATURES 5
3. PIN DESCRIPTIONS 7
3.1 PIN ASSIGNMENT BY PIN NUMBER 7
3.2 PIN-OUT DIAGRAM 7
3.3 PIN SIGNAL DESCRIPTIONS 8
4. BLOCK DIAGRAM 11
5. ORDERING INFORMATION 12
6. FUNCTION DESCRIPTIONS 13
6.1 USB INTERFACE 13
6.1.1 DEVICE DESCRIPTOR 13
6.1.2 CONFIGURATION DESCRIPTOR 14
6.1.3 USB AUDIO TOPOLOGY DIAGRAM 14
6.2 EEPROM (93C46) CONTENT FORMAT 15
6.3 HID FEATURE 16
6.3.1 WHAT’S HID 16
6.3.2 HID DESCRIPTOR 16
6.4 DYNAMIC RANGE CONTROL (DRC) 18
7. ELECTRICAL CHARACTERISTICS 19
7.1 ABSOLUTE MAXIMUM RATING 19
7.2 OPERATION CONDITIONS 19
7.3 SPERKER IMPEDANCE VS. OUTPUT POWER CONSUMPTION 20
7.4 AUDIO PERFORMANCE 20
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 4 -
8. AUDIO PERFORMANCE CURVES 22
8.1 FREQUENCY RESPONSE (10K OHM LOADING) 22
8.1.1 FREQUENCY RESPONSE @ 44.1 KS/SEC 22
8.1.2 FREQUENCY RESPONSE @ 48 KS/SEC 22
8.2 PASSBAND RIPPLE (10K OHM LOADING) 23
8.2.1 PASSBAND RIPPLE @ 44.1 KS/SEC 23
8.2.2 PASSBAND RIPPLE @ 48 KS/SEC 23
9. REFERENCE APPLICATION CIRCUIT 24
10. REFERENCE 25
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 5 -
1. DESCRIPTIONS AND OVERVIEW
CM103+ is a highly integrated single chip for USB digital control speaker application. It is a
truly plug-and-play USB audio device and provided high quality digital sound playback. This
one chip solution not only embedded USB transceiver, ADC, DAC component but also
integrated digital control power amplifier function for USB digital sound application.
Minimum external components are needed for building a high-end 2CH USB speaker
system, which makes CM103+ a simple and very cost-effective solution. Since no driver is
necessary for audio playback on all major OS.
The innovation technology DRC feature was integrated on CM103+. 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 chip to saving external
amplifier component and getting a better listening experience when listen to a music source
with wide dynamic range.
Customers can use an EEPROM to define 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. For energy saving, USB
suspend mode and resume is supported by CM103+. With power amplifier enable pin and
volume control VR input pin, a traditional speaker front panel design can be built. Moreover,
CM103+ support USB standard HID Interface which provide Vol_up / Vol_dn / Play_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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 6 -
Embedded Digital Control Power Amplifier for Speaker Driving
Support Power Amplifier Enable / Disable Control Pin
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
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
3.3V I/O with 5V Tolerance
Dolby® Digital and DTS Audio Streaming via S/PDIF Output
Compatible with Win 98SE / Win ME / Win 2000 / Win XP, and Mac OS 10.X
without additional driver
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 7 -
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
CM103+
EESK
DVDD5V
EECS
EEDW
EEDR
LEDO
MUTE
DVDD5V
DVDD5V
VP
VN
NC
AVSS
AVSS
LOR
LOR
LOR
LOR
LOL
LOL
LOL
LOL
AVDD
AVDD
NC
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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 8 -
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 Bandgap Circuit; 2.25V Output
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 9 -
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
42 GPIO
DIO, 8mA, ST,
SR, PD GPIO Pin, Controlled via Vender Specific Command
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 10 -
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)
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 11 -
4. BLOCK DIAGRAM
USB I/F
HID Control I/F
FIFO
Crystal OSC
USB
Clock Gen Audio
Clock Gen
Power 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 CM103+
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 12 -
5. ORDERING INFORMATION
Model
Number Package Operating Ambient
Temperature Supply Range
CM103+ 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)
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 13 -
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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 14 -
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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 15 -
6.2 EEPROM (93C46) CONTENT FORMAT
CM103+ 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.
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 16 -
6.3 HID FEATURE
HID feature is provided by CM103+ so 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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 17 -
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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 18 -
6.4 DYNAMIC RANGE CONTROL (DRC)
CM103+ 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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 19 -
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 Voltage 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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 20 -
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
*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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 21 -
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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 22 -
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 Sol id 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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 23 -
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
Ripple @44.1ks/sec
WL-PassbandRipple-M44k.at2c
ColorSweep T rac e Line S tyle T hi c k Data Axis Comment
1 1 Cyan Soli d 3 F asttest.Ch.1 Ampl!Nor malize Left
1 2 Yellow Solid 3 Fasttest.Ch.2 Ampl!Normalize 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 race Line Style Thick Data Axis Comment
1 1 Cyan Solid 3 Fasttest.Ch.1 Ampl!Normalize Left
1 2 Yellow Solid 3 F asttest .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
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 24 -
9. REFERENCE APPLICATION CIRCUIT
CM103+
USB Stereo Audio Chip for Digital Speakers Application
Date: 09/25/2005 Version: 1.01
- 25 -
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
－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
