W681511
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1. GENERAL DESCRIPTION
The
W681511
is a general-purpose single channel PCM CODEC with pin-selectable
-Law or A-Law
companding. The device is compliant with the ITU G.712 specification. It operates off of a single +5V
power supply and is available in 20-pin PDIP, SOG, SSOP, and TSSOP package options. Functions
performed include digitization and reconstruction of voice signals, and band limiting and smoothing
filters required for PCM systems. The filters are compliant with ITU G.712 specification.
W681511
performance is specified over the industrial temperature range of 40
C to +85C.
The
W681511
includes an on-chip precision voltage reference and an additional power amplifier,
capable of driving 300
loads differentially up to a level of 6.3V peak-to-peak. The analog section is
fully differential, reducing noise and improving the power supply rejection ratio. The data transfer
protocol supports both long-frame and short-frame synchronous communications for PCM
applications, and IDL and GCI communications for ISDN applications.
W681511
accepts seven
master clock rates between 256 kHz and 4.096 MHz, and an on-chip pre-scaler automatically
determines the division ratio for the required internal clock.
For fast evaluation and prototyping purposes, the
W681511
DK development kit is available.
2. FEATURES
Single +5V power supply
Typical power dissipation of 25 mW,
power-down mode of 0.5
W
Fully-differential analog circuit design
On-chip precision reference of 1.575 V for
a 0 dBm TLP at 600
Push-pull power amplifiers with external
gain adjustment with 300
load capability
Seven master clock rates of 256 kHz to
4.096 MHz
Pin-selectable
-Law and A-Law
companding (compliant with ITU G.711)
CODEC A/D and D/A filtering compliant
with ITU G.712
Industrial temperature range (40C to
+85
C)
Package: 20-pin SOG
APPLICATIONS
Digital Telephone Systems
Central Office Equipment (Gateways,
Switches, Routers)
PBX Systems (Gateways, Switches)
PABX/SOHO Systems
Local Loop card
SOHO Routers
VoIP Terminals
Enterprise Phones
ISDN Terminals
Analog line cards
Digital Voice Recorders
W681511
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4. TABLE OF CONTENTS
1. GENERAL DESCRIPTION.................................................................................................................. 2
2. FEATURES ......................................................................................................................................... 2
3. BLOCK DIAGRAM .............................................................................................................................. 3
4. TABLE OF CONTENTS ...................................................................................................................... 4
5. PIN CONFIGURATION ....................................................................................................................... 6
6. PIN DESCRIPTION............................................................................................................................. 7
7. FUNCTIONAL DESCRIPTION............................................................................................................ 8
7.1. Transmit Path............................................................................................................................. 8
7.2. Receive Path.............................................................................................................................. 9
7.3. Power Management................................................................................................................. 10
7.3.1. Analog and Digital Supply .............................................................................................. 10
7.3.2. Analog Ground Reference Voltage Output .................................................................... 10
7.4. PCM Interface .......................................................................................................................... 10
7.4.1. Long Frame Sync ........................................................................................................... 10
7.4.2. Short Frame Sync .......................................................................................................... 11
7.4.3. GCI Interface .................................................................................................................. 11
7.4.4. IDL Interface................................................................................................................... 12
7.4.5. System Timing................................................................................................................ 12
8. TIMING DIAGRAMS.......................................................................................................................... 13
9. ABSOLUTE MAXIMUM RATINGS.................................................................................................... 20
9.1. Absolute Maximum Ratings ..................................................................................................... 20
9.2. Operating Conditions ............................................................................................................... 20
10. ELECTRICAL CHARACTERISTICS ............................................................................................... 21
10.1. General Parameters .............................................................................................................. 21
10.2. Analog Signal Level and Gain Parameters............................................................................ 22
10.3. Analog Distortion and Noise Parameters .............................................................................. 23
10.4. Analog Input and Output Amplifier Parameters ..................................................................... 24
10.5. Digital I/O ............................................................................................................................... 26
10.5.1. -Law Encode Decode Characteristics........................................................................ 26
10.5.2. A-Law Encode Decode Characteristics ....................................................................... 27
10.5.3. PCM Codes for Zero and Full Scale ............................................................................ 28
10.5.4. PCM Codes for 0dBm0 Output .................................................................................... 28
11. TYPICAL APPLICATION CIRCUIT................................................................................................. 29
12. PACKAGE SPECIFICATION .......................................................................................................... 31
12.1. 20L SOG 300mil ................................................................................................................. 31
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