W681513
1. GENERAL DESCRIPTION
The
W681513
is a single channel PCM CODEC with pin-selectable
μ-Law
or A-Law companding
dedicated to the USB accessory market by supporting a derivative 2MHz clock. The device is
compliant with the ITU G.712 specification. It operates from a single +5V power supply and is
available in 20-pin SOP package option. 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.
W681513
performance is specified over the industrial
temperature range of –40°C to +85°C.
The
W681513
includes an on-chip precision voltage reference and an additional power amplifier,
capable of driving 300Ω 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.
W681513
accepts 2MHz
master clock rate, and an on-chip pre-scaler automatically determines the division ratio for the
required internal clock.
2. FEATURES
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Single +5V power supply
Typical power dissipation of 30 mW,
power-down mode of 0.5
μW
Fully-differential analog circuit design
On-chip precision reference of 1.575 V for
a 0 dBm TLP at 600
Ω
(775mV
RMS
)
Push-pull power amplifiers with external
gain adjustment with 300
Ω
load capability
Master clock rate supports 2.000MHz
clock for USB applications
Pin-selectable
μ-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 (–40°C to
+85°C)
Package: 20-pin SOP (SOG)
Pb-Free / RoHS package option available
Applications
•
Soft phones running on a PC (VoInternet):
o
o
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USB Phones
USB to PSTN Gateway
USB Microphones
USB Headset for PC and Game Consoles
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W681513
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 Outpt ............................................................................. 10
7.4. PCM Interface .............................................................................................................................. 10
7.4.1. Long Frame Sync.................................................................................................................. 10
7.4.2. Short Frame Sync ................................................................................................................. 11
7.4.3. General Circuit Interface (GCI) ............................................................................................. 11
7.4.4. Interchip Digital Link (IDL)..................................................................................................... 12
7.4.5. System Timing ...................................................................................................................... 12
8. TIMING DIAGRAMS.......................................................................................................................... 13
9. ABSOLUTE MAXIMUM RATIINGS................................................................................................... 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.
μ-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 CIRCUITS .............................................................................................. 29
12. PACKAGE SPECIFICATION .......................................................................................................... 32
12.2. 20L SOP (SOG)-300mil ............................................................................................................. 32
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