AS2533UT

Overview

The AS2533UT is a CMOS integrated circuit designed for electronic telephone sets, incorporating a line interface, speech circuit, dialler, and ringer. It operates on a single supply voltage of 3.8V to 5V with a typical operating current of 4mA in speech mode. The device supports LD/MF dialing, 31-digit last number redial, and memory functions including four direct and ten indirect memories. It features electronic volume control, microphone mute, and automatic line loss compensation. The IC is housed in a 28-pin SOIC package and operates within a temperature range of -25°C to +70°C.

Feature Summary

• Integrated line interface with real or complex impedance support and stabilized supply for peripherals
• Speech circuit featuring electronic receive volume control, microphone mute, and symmetrical microphone amplifier inputs
• Dialler supporting LD/MF dialing, mixed-mode dialing, and sliding cursor protocol for PABX compatibility
• Tone ringer with three-tone melody generator and programmable ring frequency discrimination

Applications

• Basic electronic telephone sets
• Telecommunications equipment requiring single-chip integration
• PABX compatible telephony systems

Procurement Notes

Verify the specific ordering suffix UT against the manufacturer's official documentation to confirm package type and tape-and-reel specifications. Confirm that the component status remains active or identify valid obsolescence notices before procurement. Ensure the supplier provides original manufacturer data sheets to validate pin compatibility and electrical characteristics.

Selection Notes

Select this component for applications requiring a single-chip solution for basic telephony functions. Consider the AS253x family variants based on required memory configurations, such as direct versus indirect memory keys. Verify compatibility with external components like ceramic resonators and keyboard matrices. Ensure the design accommodates the specified operating voltage and current ranges for reliable performance.

Part Context

The AS2533UT belongs to the AS253x family of multi-standard CMOS telephone ICs manufactured by ams AG. This family includes variants like the AS2533, AS2534, AS2535, and AS2536, which share pin compatibility but differ in memory and feature sets. The AS2533 specifically offers four direct and ten indirect memory keys, distinguishing it from other models in the series.

Replacement Considerations

Direct replacements within the AS253x family include the AS2533, AS2534, AS2535, and AS2536, provided their specific feature sets align with the application requirements. Verify pin compatibility and functional differences such as memory capacity and dialer options before substitution.