DS2167/DS2168
DS2167/DS2168
ADPCM Processor
FEATURES
PIN ASSIGNMENT
• Speech compression chip compatible with standard
VDD
YIN
1
2
3
RST
TM0
TM1
A0
24
ADPCM algorithms:
23
22
CLKY
FSY
–
–
DS2167 supports “new” T1Y1 recommenda-
tions (July 1986) and “new” CCITT G.721 rec-
ommendations
21
20
4
5
YOUT
CS
A1
A2
19
18
17
16
DS2168 supports “old” CCITT G.721 recom-
mendations
6
7
SDI
A3
SCLK
XOUT
FSX
A4
8
9
• Dual independent channel architecture – device may
be programmed to perform full duplex, 2-channel ex-
pansions, or 2-channel compressions
A5
15
SPS
MCLK
VSS
10
11
12
CLKX
XIN
14
13
• Interconnects directly with µ-law or A-law codec/filter
devices
24-Pin DIP (600 MIL)
• Serial PCM and control port interfaces minimize “glue
logic” in multiple channel applications
–
–
–
On-chip channel counters identify input and out-
put timeslots in TDM-based systems
27 26
1 28
NC
A0
A1
A2
4
3 2
5
FSY
YOUT
25
6
7
8
9
24
23
CS
Unique addressing scheme simplifies device
control; 3-wire port shared among 64 devices
22
21
SDI
A3
A4
SCLK
XOUT
Bypass and idle features allow dynamic alloca-
tion of channel bandwidth, minimize system
power requirements
10
11
20
19
A5
NC
12 1314 15 16 1718
• Hardware mode intended for stand-alone use
–
–
No host processor required
28-Pin PLCC
Ideal for voice mail applications
• 28-pin surface-mount package available, designated
DS2167Q/DS2168Q
DESCRIPTION
The DS2167 and DS2168 are dedicated digital signal
processor (DSP) CMOS chips optimized for Adaptive
Differential Pulse Code Modulation (ADPCM) based
compression algorithms. The devices halve the trans-
missionbandwidth of “toll quality” voice from 64K to 32K
bits/second and are utilized in PCM-based telephony
networks.
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