AS2534UT

Overview

The AS2534UT is a CMOS integrated circuit designed for basic electronic telephone sets. It integrates a line interface, speech circuit, dialler, and ringer into a single die with 28 pins. The device supports LD/MF dialing, last number redial (LNR), and ring frequency discrimination. It operates within a supply voltage range of 3.8V to 5V and an operating temperature of -25°C to +70°C. Key electrical parameters include a typical transmit gain of 36.6 dB and receive gain of 3 dB. The IC features electronic volume control, microphone mute, and automatic line loss compensation.

Feature Summary

• Integrates line interface, speech processing, dialling logic, and tone ringer generation
• Supports Last Number Redial (LNR) with sliding cursor protocol for PABX compatibility
• Features electronic receive volume control and microphone mute functions
• Includes ring frequency discrimination and programmable melody/volume settings

Applications

• Basic electronic telephone sets
• PABX compatible telephony systems
• Telephones requiring LD/MF mixed-mode dialling

Procurement Notes

Verify the specific suffix UT against official documentation to confirm pinning and feature set alignment. Confirm package availability as the datasheet lists SOIC 28 or DIE options. Ensure the supplier provides valid traceability for this legacy component series.

Selection Notes

Select the AS2534UT when zero direct memory keys are required but LNR functionality is needed. Compare against AS2533/36 if indirect memories are necessary. Verify mode pin configurations for LD/MF requirements. Check keyboard matrix compatibility with VOL or +/- key implementations.

Part Context

The AS2534UT belongs to the AS253x family from ams AG (formerly austriamicrosystems). This family provides versatile single-chip solutions for telephony applications. The AS2534 variant specifically excludes direct memory keys while retaining LNR and repeat dialing capabilities found in other family members.

Replacement Considerations

The AS2534R is a pin-compatible variant within the same family. Differences include fixed ring melody and volume settings versus programmable ones. Verify functional equivalence before substitution.