L9215A/G
Short-Loop Sine Wave Ringing SLIC
Data Sheet
September 2001
■ Ring trip detector is turned off to conserve power.
■ On-hook transmission is allowed.
State Definitions (continued)
On-Hook Transmission with PPM—Forward
Battery
■ The tip-to-ring on-hook differential voltage will be
between –41 V and –49 V with a –70 V primary bat-
tery.
■ Pin PT is positive with respect to PR.
■ PPM is on.
■ VBAT1 is applied to tip/ring drive amplifiers.
■ Supervision circuits, loop closure, and common-
mode detect are active.
Disconnect
■ Ring trip detector is turned off to conserve power.
■ On-hook transmission is allowed.
■ The tip/ring amplifiers and all supervision are turned
off.
■ The SLIC goes into a high-impedance state.
■ NSTAT is forced high (on-hook).
■ The tip-to-ring on-hook differential voltage will be
between –41 V and –49 V with a –70 V primary bat-
tery.
■ PPM is on.
Ring
■ Power ring signal is applied to tip and ring.
■ Input waveform at RINGIN is amplified.
On-Hook Transmission—Reverse Battery
■ Pin PR is positive with respect to PT.
■ Ring trip supervision and common-mode current
supervision are active; loop closure is inactive.
■ VBAT1 is applied to tip/ring drive amplifiers.
■ Supervision circuits, loop closure, and common-
mode detect are active.
■ Overhead voltage is reduced to typically 4 V, regard-
less of programming on OVH, and current limit set at
VPROG is disabled.
■ Ring trip detector is turned off to conserve power.
■ On-hook transmission is allowed.
■ Current is limited by saturation current of the amplifi-
ers themselves, typically 100 mA at 125 °C.
■ The tip-to-ring on-hook differential voltage will be
between –41 V and –49 V with a –70 V primary bat-
tery.
Thermal Shutdown
■ PPM is off.
■ Not controlled via truth table inputs.
■ NSTAT is forced low (off-hook) during this state
On-Hook Transmission with PPM—Reverse
Battery
■ This mode is caused by excessive heating of the
device, such as may be encountered in an extended
power cross situation.
■ Pin PR is positive with respect to PT.
■ VBAT1 is applied to tip/ring drive amplifiers.
■ Supervision circuits, loop closure, and common-
mode detect are active.
Agere Systems Inc.
13
AGERE [ AGERE SYSTEMS ]
