New SIDACtor Protection Thyristors to Safeguard SLIC Interfaces from Surges

Littelfuse, Inc., the global leader in circuit protection, today introduced two series of SIDACtor® Protection Thyristors designed to protect SLIC (Subscriber Line Interface Circuit) interfaces against lightning-induced surges and power fault events. The surface-mount B61089QDR and B9110DF Series Thyristors for Programmable Tracking Protection contain fast-switching crowbarring structures that are compatible with the Basic levels outlined in the ITU K.20, K.21 and K.45 recommendations from the International Telecommunications Union (ITU). 

The B61089QDR Dual-Port Battrax provides surge protection for SLIC cards that have only implemented negative voltage ringing. The B9110DF Series provides surge protection for SLIC cards that have implemented both positive and negative voltage ringing, which are used in most telecommunications applications today. It also tracks the Vcc reference of the SLIC chipset so that if/when it enters a low quiescent stage, the protection threshold will match this lower threshold.

Applications for the B61089QDR and B9110DF Series include protection for:

• Wireless in the Local Loop (WLL) systems,
• Voice applications that require regenerated POTS (Plain Old Telephone Service) signals,
• Voice over IP (VoIP) applications,
• Private Branch Exchange (PBX) systems,
• Foreign Exchange Station (FXS) applications,
• Digital Pair Gain systems (DPG),
• Digital Loop Carrier (DLC) systems, and
• Small Office, Home Office (SOHO) systems.

“The B61089QDR and B9110DF Series provide crowbarring power fault protection at levels far superior to the typical clamping device,” said Jeff Chin, product line director for SIDACtor Protection Thyristors at Littelfuse. “They combine superior surge protection performance with a low switching threshold and low on-state voltage to ensure better protection.”

B61089QDR and B9110DF Series SIDACtor Protection Thyristors offer these key benefits:

• High performance protection for SLICs with + VBAT and –VBAT references for the B9110DF Series and –VBAT reference for the B61089QDR Series and with changing VBAT references.
• Prevent component property degradation after multiple surge events within the rated limits, thereby extending equipment lifetime.
• Help line drivers comply with global standards because these devices are certified, environmentally friendly and suitable for worldwide usage.

About Littelfuse

Littelfuse is a global manufacturer of leading technologies in circuit protection, power control, and sensing. Serving over 100,000 end customers, our products are found in automotive and commercial vehicles, industrial applications, data and telecommunications, medical devices, consumer electronics, and appliances. Our 11,000 worldwide associates partner with customers to design, manufacture and deliver innovative, high-quality solutions, for a safer, greener, and increasingly connected world – everywhere, every day.