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CM 108AH Highly Integrated USB Audio I/O Controller www .cmedia.com.tw Copyright© C-Media Electro nics Inc. R ev . 2.1 ︱ P age 9 /27 5 Block Diagr am USB TRX USB interface 4 byte FIFO USB control processing ISO out proce…
CM108AH
Highly Integrated USB Audio I/O Controller
www.cmedia.com.tw
Copyright© C-Media Electronics Inc. Rev. 2.1︱ Page 8/27
4 I²S Interface
The CM108AH provides an IP
2
P
S interface for both playback and recording. External ADC, DAC, or DSP can be
added to provide additional functions within the USB audio system. The CM108AH sends out master clock (fixed
at x256), LRCK (fixed at x64), and data clock data. Therefore, external ADCs, DACs, or DSPs should be set to
slave mode.
The left channel of the CM108AH’s IP
2
P
S bus is used for mono recording. Both IP
2
P
S buses use a 5V tolerant pad in
order to easily interface with 5V or 3.3V devices. Playback data is simultaneously sent to both the DAC and IP
2
P
S
bus. The recording source (ADC or IP
2
P
S bus) can be selected by ADSEL jumper pin.
LRCK
SCLK
MSB -1 -2 +2 +1 LSB MSB -1 -2 +2 +1 LSB
SDATA
Left Channel
Right Channel
CM108AH
Highly Integrated USB Audio I/O Controller
www.cmedia.com.tw
Copyright© C-Media Electronics Inc. Rev. 2.1︱ Page 9/27
5 Block Diagram
USB
TRX
USB
interface
4 byte
FIFO
USB control
processing
ISO out
processing
( with x2 mod)
PLL1
48 MHz
ROM
PLL2
12. 288 /11. 2896 MHz
with adjustment
12 MHz
VREF
(2.25V)
power on
reset
reset
16 bit
DAC
bandgap
3.3V
+
-
+
-
Vref
5 - > 3. 3
regulator
REGV
ISO in
processing
300 x 16 SRAM
16 bit Sigma-
Delta ADC
16 bit
DAC
+
-
Vref
+22.5~ - 0 dB
16 steps
Vref
PLL3
12. 288/
11. 2896 MHz
USB interrupt
processing with 4
byte FIFO
interface logics
MUTER
MCU
I/F
VOLDN
VOLUP
VREF
MUTEP
LOL
LOR
LEDO
LEDR
PDSW
+
-
+22. 5 ~ 0 dB
16 steps
Vref
0 ~ -45dB
38 steps
voltage linear
VBIAS
4.5 V ( drive typ 4mA)
EEPROM
interface
CS
SK
DW
DR
USBDP
USBDM
XI
XO
MICIN
+
-
Vref
Vref
+
-
+
-
Vref
LOBS
GPIO
BOOST
+22.5
dB boost enable
0 ~ -45dB
38 steps
voltage linear
PWRSEL
MODE
SEL pins
TEST
sync by
VPR_CLK
sync by
VPL_CLK
BUZZ
IIS I/F
SPDIFO
High-Pass Filter
CM108AH Block Diagram
CM108AH
Highly Integrated USB Audio I/O Controller
www.cmedia.com.tw
Copyright© C-Media Electronics Inc. Rev. 2.1︱ Page 10/27
6 Ordering Information
Model No.
Package
Operating Ambient
Temperature
Supply Range
CM108AH
48-pin LQFP, 7mm × 7mm × 1.4mm (plastic)
-15°C to +70°C
DVdd = 5V, AVdd = 5V
Note: Outline Dimensions are shown in inches and millimeters
48-Lead Thin Plastic Quad Flatpack (LQFP)
CM108AH Ordering Information