Description
This general-purpose electronic subscriber loop interface circuit (SLIC) is optimized for low cost, while still providing a satisfactory set of features. This part is a pin-for-pin replacement for the Agere L9217 and L9218 SLICs.
The L9219 requires a 5 V power supply and single battery to operate. This device offers forward and reverse battery operation. The rate of battery reversal may be ramped to meet international requirements. Additionally, a low-power scan mode, wherein all circuitry except the off-hook supervision is shut down to conserve power, is available.

Features
■ Basic forward/reverse battery SLIC functionality at a low cost
■ Pin compatible with Agere Systems Inc. L9217 and L9218 SLICs
■ Low active power (typical 138 mW during on-hook transmission)
■ Low-power scan mode for low-power, on-hook power dissipation (52 mW typical)
■ Distortion-free, on-hook transmission
■ Convenient operating states:
    — Forward active-low current limit
    — Forward active-high current limit
    — Reverse active-low current limit
    — Reverse active-high current limit
    — Low-power scan
    — Disconnect (high impedance)
■ Minimal external components required
■ Two gain options to optimize the codec interface
■ Adjustable supervision functions:
    — Off-hook detector with hysteresis
    — Ring trip detector
■ Logic controlled high and low current limit
■ Ramped rate of battery reversal
■ Thermal protection with thermal shutdown indication