General Description
The HT9033 is a CPE Alerting Signal (CAS) tone receiver integrated with digital filter/detector and analog front end circuit. The HT9033 using analog filter techniques to achieve very high precision detection for the present of CAS tone. It is ideal for receiving physical layer signal like Bellcores CPE Alerting Signal (Type II caller ID) and similar evolving services like ETS/BT.

Features
• Operating voltage: 3.5V~5.5V
• Differential input
• Power down control
• Bellcore CAS detection (Type II)
• 3.58MHz clock input
• Low standby current
• High sensitivity: 33dBm
• Data valid output
• 16-pin DIP/SOP package

Applications
• Feature phone system
• Caller ID with Call Waiting
• Computer telephony interface products
• Analog Display Service Interface (ADSI)