AS2533UTT

Overview

The AS2533UTT is a CMOS integrated circuit designed for high-performance electronic telephone sets with basic features. It incorporates a line interface, speech circuit, dialler, and ringer within a single chip. The device supports LD/MF dialing, mixed-mode dialing, and offers memory functions including 4 direct and 10 indirect memories. It operates on a supply voltage of 3.8V to 5V with an operating current of 4mA in speech mode. The IC is available in a 28-SOIC package or as a die, suitable for surface mount or chip-on-board mounting.

Feature Summary

• Integrated line interface with electronic volume control and microphone mute capabilities
• Supports LD/MF dialing with last number redial and multiple memory options
• Features a 3-tone melody generator with programmable ring frequency discrimination
• Includes automatic line loss compensation and stabilized supply for peripherals

Applications

• Electronic telephone sets with basic features
• PABX systems requiring sliding cursor protocol
• Telecom interfaces needing LD/MF mixed-mode dialing

Procurement Notes

Verify the specific suffix 'UTT' against the manufacturer's datasheet to confirm bond options and pin compatibility. Ensure the ordering information matches the required feature set, such as direct and indirect memory configurations. Confirm package availability and lead times directly with authorized distributors or the manufacturer.

Selection Notes

Select the AS2533 variant when 4 direct and 10 indirect memory keys are required. Compare with AS2536 if identical memory features are needed but different packaging or minor electrical characteristics are preferred. Consider AS2535 if 12 direct memories are sufficient and indirect memories are not needed. Verify PTT requirements for impedance and line loss compensation settings.

Part Context

The AS2533 is part of the AS253x family from ams OSRAM (formerly austriamicrosystems). This family includes pin-compatible variants like the AS2534, AS2535, and AS2536, which differ primarily in memory configurations and dialing features. The AS2533 specifically provides a balance of direct and indirect memory access for standard telephone applications.

Replacement Considerations

The AS2536 is a pin-compatible alternative offering the same 4 direct and 10 indirect memory configuration. Verify that any replacement maintains the required LD/MF dialing modes and ringer programming capabilities. Check for any changes in electrical characteristics or package dimensions before substitution.