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