V.90/K56flex Modem Device Sets with SmartDAA Technology for Low Power Applications

SmartACFL

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Doc. No. 100444A

Conexant

9

Proprietary Information

SmartDAA Line Side Device (LSD)

The LSD includes a Line Side DIB Interface (LSDI),

a coder/decoder (codec), and a Telephone Line

Interface (TLI).

The LSDI communicates with, and receives power

and clock from, the SmartDAA interface in the MDP

through the DIB.

LSD power is received from the top of the DIB

DXFMR secondary winding through a half-wave

rectifying diode and capacitive power filter circuit.

The CLK input is also accepted from the top of the

DXFMR secondary winding through a capacitor and

a resistor in series.

Information is transferred between the LSD and the

MDP through the DIB_P and DIB_N pins. These pins

connect to the MDP DIB_DATAP and DIB_DATAN

pins, respectively, through the DIB.

The TLI integrates DAA and direct telephone line

interface functions and connects directly to the line

TIP and RING pins, as well as to external line

protection components.

Direct LSD connection to TIP and RING allows real-

time measurement of telephone line parameters,

such as the telephone central office (CO) battery

voltage and individual telephone line (copper wire)

resistance. Direct LSD connection also allows

dynamic regulation of the off-hook TIP and RING

voltage and total current drawn from the CO. This

allows the modem to maintain compliance with U.S.

and worldwide regulations and to actively control the

DAA power dissipation.

Voice Codec (VC)

The optional VC, packaged in a 32-pin TQFP,

supports voice/full-duplex speakerphone (FDSP)

operation with interfaces to a microphone and

speaker and to a telephone handset/headset.