STLC30R80

Telecom Overview

The STLC30R80 is an integrated ringing Subscriber Line Interface Circuit (SLIC) designed for short loop applications. It implements all key features of the BORSHT function, including battery feeding, overvoltage protection, ring trip detection, and signaling. The device supports dual control mode configurations: slave mode or automatic activation mode. Key electrical parameters include a positive supply voltage range of 4.75 to 5.25 V, a negative battery voltage range of -72 to -15 V, and a control interface supply voltage of 3 to 5.25 V. It operates within a temperature range of -40 to +85°C and is housed in a TQFP44 surface mount package.

Telecom Feature Summary

• Implements complete BORSHT functionality with programmable DC characteristics for battery feeding and limiting current up to 50mA.
• Supports soft battery reversal with programmable transition time and automatic dual battery operation.
• Features integrated ring trip detection with automatic and synchronized ring disconnection upon off-hook sensing.
• Provides metering pulse injection capability and supports both loop start and ground start transmission modes.

Telecom Applications

• Short loop subscriber line interface circuits
• Public telephone network terminals
• Integrated PBX systems

Telecom Procurement Notes

Verify component authenticity through authorized STMicroelectronics distributors. Confirm the specific ordering suffix matches the required package and temperature grade. Check for obsolete status notifications as this product may be discontinued. Ensure proper ESD handling protocols are followed during storage and assembly.

Telecom Selection Notes

Select this component specifically for short loop applications where standard long-loop compensation is unnecessary. Evaluate external component requirements for impedance synthesis and protection circuits. Consider thermal dissipation needs when designing the PCB layout for the TQFP44 package.

Telecom Part Context

This SLIC belongs to STMicroelectronics' telecommunications interface portfolio. It serves as a monolithic solution for analog telephony lines, replacing discrete BORSHT implementations. The device integrates logic interfaces and decoders to simplify system architecture.

Telecom Replacement Considerations

Check for direct pin-compatible replacements from STMicroelectronics or third-party manufacturers. Verify that substitute components support the same short loop application constraints and BORSHT feature set.

Telecom FAQ

How is the ring trip detection implemented?

Ring trip detection is performed by sensing the variation of AC line impedance from on-hook (high) to off-hook (low). Upon detection, the device automatically disconnects the ringing signal without waiting for a controller command.

What is the purpose of the Rswitch resistor?

The Rswitch resistor improves AC current capability in Ring mode to avoid false ring trips in high REN number or short loop scenarios. It reduces ring trip sensitivity on long loops, so its value must be adjusted carefully.

How does the device handle battery reversal?

The STLC30R80 allows for soft battery reversal with a programmable transition time defined by the CREV capacitor. This process occurs without affecting AC signal transmission.