CDB6422 Cirrus Logic Inc, CDB6422 Datasheet - Page 13
CDB6422
Manufacturer Part Number
CDB6422
Description
Development Kit
Manufacturer
Cirrus Logic Inc
Datasheet
1.CDB6422.pdf
(30 pages)
Specifications of CDB6422
Silicon Manufacturer
Cirrus Logic
Application Sub Type
Telephone
Kit Application Type
Communication & Networking
Silicon Core Number
CS6422
Description/function
Audio DSPs
Operating Supply Voltage
5 V to 12 V
Product
Audio Modules
Kit Contents
Evaluation Board
Rohs Compliant
No
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
For Use With/related Products
CS6422
acoustic coupling between AO and APO to -9dB (a
design target).
In a desktop speakerphone, the acoustic coupling is
typically altered by adjusting the mic preamp gain.
In a hands-free car kit, the acoustic coupling is typ-
ically altered by adjusting the speaker and mic po-
sition.
For this exercise, NIN4 should be set to ‘ACTIVE’,
and there should be no signal connected to
NIN_RCA.
1) Configure the CS6422 from RESET with the
2) Adjust the speaker/mic position until the sys-
3) In the desktop telephone application (where the
4.3
Acoustic input using external microphone and in-
ternal mic preamp:
AIN1 = MIC
MIC_BIAS = ENABLED
AIN2 = ACTIVE
AIN3 = FIXED
AIN4 = 0dB
AIN5 = ACTIVE
AIN6 = ON
AIN7 = ON
DS295DB2
following:
tem is just on the verge of howling. At this
point the loop gain is approximately equal to
0dB. The above register configuration sets a
gain of +9dB between APO and AO. When the
speaker and mic are placed such that the system
is on the verge of howling, the coupling be-
tween AO and APO is approximately -9dB.
speaker and microphone are not mobile), adjust
the mic preamp gain until the system is just on
the verge of howling.
Jumper configuration:
reg 0: 57a0 (d7a0 if the internal mic preamp
reg 1: 26a2 -- TVol = +12dB
reg 5: 003a -- NSdt = -12dB
is used) -- RVol = +9dB
(Alternate) Acoustic input using AIN_RCA with
no mic bias and internal mic preamp disabled:
AIN1 = RCA
MIC_BIAS = DISABLED
AIN2 = ACTIVE
AIN3 = FIXED
AIN4 = 0dB
AIN5 = ACTIVE
AIN6 = OFF
AIN7 = OFF
-- NOTE: 'Mic' bit in Register 0 should be '0' for
this configuration!
Acoustic output using 3-pole Butterworth filter and
speaker driver set to 0dB (1/4 Watt into 4 ohms).
AOUT1 = ACTIVE
AOUT2 = 3-POLES
AOUT3 = FIXED
AOUT4 = 0dB
AOUT5 = GAINED
AOUT6 = AC
SPEAKER_GAIN = 0dB
Network input (input source varies based on sce-
nario):
NIN1 = ACTIVE
NIN2 = FIXED
NIN3 = 0dB
NIN4 = ACTIVE, POTS(DAA), or CODEC de-
pending on signal source
Network output using 3-pole Butterworth filter:
NOUT1 = ACTIVE
NOUT2 = 3-POLE
NOUT3 = FIXED
NOUT4 = 0dB
NOUT5 = GAINED
NOUT6 = AC
Other Jumper Settings:
HDR94 "RUN" installed
HDR90 "uC" installed
HDR86 "DTMF_TX" installed
CDB6422
13