CS6422
CS6422
Enhanced Full-Duplex Speakerphone IC
Enhanced Full-duplex Speakerphone IC
Features
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.
l Single-chip, 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
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.
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
The CS6422 consists of telephone & audio interfaces,
two codecs and an echo-cancelling DSP.
l Microcontroller Interface
ORDERING INFORMATION
See page 48.
CS6422-IS
-40o to 85oC
20-pin SOIC
CDB6422 Evaluation Board
NC1 NC2 NC3
NC4
12
DVDD
16
AVDD
1
9
10
11
RGain
RVol
3
+
+
17
Rx
NI
ADC
DAC
AO
Σ
Suppression
-
14
(0, 6, 9.5, 12 dB)
(Mute, -12 to +30 dB)
CLKI
Pre-emphasis
Clock
Generation
13
Network
Echo
Canceller
Filter
CLKO
Acoustic
Sidetone
(none, -24,
ASdt
Network
Sidetone
(none, -24,
Mic
20
Acoustic
Echo
Canceller
-18, -12 dB)
API
NSdt
-18, -12 dB)
Pre-emphasis
Filter
34 dB
1 k
Ω
-
+
TGain
TVol
18
Tx
Suppression
4
+
NO
DAC
Σ
ADC
APO
(0, 6, 9.5, 12 dB)
Voltage
(Mute, -12 to +30 dB)
Microcontroller Interface
Reference
8
7
6
5
15
2
19
This document contains information for a new product.
Cirrus Logic reserves the right to modify this product without notice.
Preliminary Product Information
Copyright Cirrus Logic, Inc. 2001
Copyright © Cirrus Logic, Inc. 2005
JUL ‘01
SEP ‘05
P.O. Box 17847, Austin, Texas 78760
(512) 445 7222 FAX: (512) 445 7581
http://www.cirrus.com
http://www.cirrus.com
(All Rights Reserved)
(All Rights Reserved)
DS295PP4
DS295F1
1