CS6422
CS6422
Enhanced Full-Duplex Speakerphone IC
Enhanced Full-duplex Speakerphone IC
Features
l
Single-chip,
General Description
Most modern speakerphones use half-duplex operation,
which alternates transmission between the far-end talker
and the speakerphone user. This is done to ensure sta-
bility because the acoustic coupling between the
speaker and microphone is much higher in speaker-
phones than in handsets where the coupling is
mechanically suppressed.
The CS6422 enables full-duplex conversation using
echo cancellation and suppression in a single-chip solu-
tion. The CS6422 can easily replace existing half-duplex
speakerphone ICs with a huge increase in conversation
quality.
The CS6422 consists of telephone & audio interfaces,
two codecs and an echo-cancelling DSP.
CS6422-IS
-40
o
to 85
o
C
20-pin SOIC
CDB6422
Evaluation
Board
full-duplex, hands-free operation
l
Optional Tx Noise Guard
l
Programmable attenuation during double-talk
l
Optional 34 dB microphone preamplifier
l
Dual channel AGC’ed volume controls with
mute
l
Dual integrated 80 dB IDR codecs
l
Speech-trained Network and Acoustic Echo
Cancellers
l
Rx and Tx supplementary echo suppression
l
Configurable half-duplex training mode
l
Powerdown mode
l
Microcontroller Interface
NC1
9
RGain
NI
17
(0, 6, 9.5, 12 dB)
ADC
NC2
10
+
+
NC3
11
NC4
12
RVol
DVDD
16
Rx
Suppression
Pre-emphasis
Filter
AVDD
1
DAC
Clock
Generation
Acoustic
ASdt Sidetone
(none, -24,
-18, -12 dB)
Mic
3
14
13
AO
CLKI
CLKO
Σ
-
(Mute, -12 to +30 dB)
Network
Echo
Canceller
Network
Sidetone
(none, -24, NSdt
-18, -12 dB)
Pre-emphasis
Filter
NO
4
DAC
Tx
Suppression
TVol
Acoustic
Echo
Canceller
-
Σ
(Mute, -12 to +30 dB)
+
+
20
34 dB
API
1 kΩ
TGain
ADC
(0, 6, 9.5, 12 dB)
Voltage
Reference
5
15
2
19
18
APO
Microcontroller Interface
8
7
6
Preliminary Product Information
http://www.cirrus.com
This document contains information for a new product.
Cirrus Logic reserves the right to modify this product without notice.
Copyright
Cirrus
Copyright
©
Cirrus Logic, Inc. 2005
Logic, Inc. 2001
(All Rights Reserved)
(All Rights Reserved)
JUL
‘05
SEP
‘01
DS295PP4
DS295F1
1
CIRRUS [ CIRRUS LOGIC ]
