GENERAL DESCRIPTION
The UBA1702; UBA1702A performs the high voltage interface and ringer functions of the corded analog telephone set in close cooperation with a microcontroller and transmission circuit.

FEATURES
Speech part
• Driver for the line interrupter that can be either a PMOST when UBA1702 is used or a PNP when UBA1702A is used
• Adjustable over-current protection
• Adjustable over-voltage protection for transmission circuit
• Adjustable mute (dialling mode voltage; DMO or NSA)
• Adjustable current loop detection (hook switch status)
• Microcontroller supply
• Provision for electronic hook switch.
Ringer part
• Over-voltage protection
• Ringer frequency output for frequency discrimination
• Adjustable ringer threshold for piezo-driver enable
• Three bits ringer volume control
• Bridge-tied-load (BTL) output stage for piezo transducer
• Fast start-up microcontroller supply.