Preliminary Data Sheet
September 2001
T8535B/T8536B Quad Programmable Codec
Features
I
5 V operation
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Per-channel programmable gains, equalization,
termination impedance, and hybrid balance
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Programmable
μ
-law, linear, or A-law modes:
— Up to 256 time slots per frame
— Supports PCM data rates of 512 kbits/s to
16.384 Mbits/s
— Double-clock mode timing compatible with
ISDN standard interfaces
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Fully programmable time-slot assignment with bit
offset
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Analog and digital loopback test modes
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Serial microprocessor interface:
— Normal and byte-by-byte control modes
— Fast scan mode
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Six bidirectional control leads per channel, for
SLIC and line card function control
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Differential analog output:
— Mates directly to SLICs, eliminating external
components
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Sigma-delta converters with dither noise reduction
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Quad design to minimize package count on dense
line card applications
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Meets or exceeds ITU-T G.711—G.712 and rele-
vant
Telcordia Technologies
requirements
Description
The device consists of four independent channels of
codec and digital signal processing functions on one
chip. In addition to the classic A-to-D and D-to-A con-
version, each channel provides termination imped-
ance synthesis and a hybrid balance network.
The device is controlled by a serial microprocessor
interface, and a series of bidirectional I/O leads are
provided so that this control mechanism can be uti-
lized to operate the battery feed device, ringing volt-
age switches, etc. Common data and clock paths can
be shared over any number of devices. All the filter
coefficients, signal processing, SLIC, and test fea-
tures are accessible through this interface. This
serial interface can be operated at speeds up to
4.096 Mbits/s.
The choice of a PCM bus is also programmable, with
any channel capable of being assigned to any time
slot. The PCM bus can be operated at speeds up to
16.384 Mbits/s, allowing for a maximum of 256 time
slots. Separate transmit and receive interfaces are
available for 4-wire bus designs, or they can be
strapped together for a 2-wire PCM bus.
The device is available in four packages:
The T8536B 64-pin TQFP features five data latches
per channel and the 100-pin TQFP features six-data
latches per channel. Both devices have two PCM
ports and are pin-compatible with the T8538B 3.3 V
Quad Programmable Codec.
The T8536B 68-pin PLCC features six data latches
per channel and has one PCM port. This device is
pin-compatible with the T8534 Quad Programmable
Echo Canceller Codec.
The T8535B 44-pin PLCC has no data latches and
has one PCM port. This device is pin-compatible with
the T8533 Quad Programmable Echo Canceller
Codec.