Infineon PEF22554HT: The High-Voltage Interface IC Powering Modern Telecom Systems

In the demanding world of telecommunications infrastructure, reliability and performance are paramount. The Infineon PEF22554HT stands as a specialized High-Voltage Interface IC engineered to meet the rigorous requirements of central office and line card applications. This component serves as a critical link between the low-voltage digital core of telecom systems and the high-voltage, high-impedance analog telephone lines they connect to, forming the backbone of both conventional and next-generation network equipment.

The primary function of the PEF22554HT is to provide a complete Subscriber Line Interface Circuit (SLIC) solution. It integrates all necessary functions for a fully-featured BORSHT capability, which is the industry acronym for:

Battery Feed

Overvoltage Protection

Ringing

Supervision

Hybrid (2-wire to 4-wire conversion)

Testing

A key differentiator of this IC is its ability to operate directly from a high-voltage supply rail (-48V or -60V typical), eliminating the need for external DC-DC converters in many designs. This integration significantly simplifies board layout, reduces the overall component count, and enhances system reliability. Its robust design includes advanced overvoltage and surge protection circuitry, safeguarding sensitive system components from transient spikes and lightning strikes common in outdoor plant environments.

Furthermore, the PEF22554HT features an on-chip programmable codec (coder-decoder) and filters, enabling direct interfacing with digital signal processors (DSPs) or system controllers through a standard serial PCM (Pulse Code Modulation) highway. This allows for the seamless transmission of voice data in a digital format, which is essential for Voice over IP (VoIP) gateways and digital switching systems. Its programmability offers designers flexibility in configuring parameters such as gain, impedance matching, and transmit/receive levels to comply with various international telecom standards.

ICGOODFIND: The Infineon PEF22554HT is a highly integrated, robust, and versatile high-voltage interface IC that remains a cornerstone technology for telecom line cards. Its comprehensive integration of BORSHT functions, coupled with superior protection features and direct high-voltage operation, provides designers with a reliable and efficient solution that reduces design complexity and total system cost while ensuring exceptional performance in harsh operational conditions.

Keywords: Subscriber Line Interface Circuit (SLIC), High-Voltage IC, BORSHT, Telecom Line Card, Overvoltage Protection