The B61089BDR is a single channel SLIC ( Subscriber Line Interface circuit ) battery tracking protector. It consists of a pair of identical protection thyristors integrated with two anti-series diodes to protect the SLIC against lightning induced surges and power fault events. The gated thyristor protectors which have crowbarring function, provide tracking battery protection down to -170V. The anti-series diode provides protection of positive surge events by diverting the surge energy to the ground. The B61089BDR has a robust surge current capability which help the telecom and datacom products to comply with different surge standards such as Telcordia GR-1089, ITU-T K.20, K.21 and YD/ T950. For compliance with Enhanced Levels test conditions of ITU-T, TIA968-B, or GR-1089, additional series resistance in the Tip / Ring pairs may be required. The SLIC chipset voltage reference may change as the on-hook/ off-hook line condition changes. Therefore, this component is referenced to the - VBAT so that its negative protection threshold follows this changing reference voltage level. This B61089BDR utilizes a transistor gain network so that a low 5 mA current level will activate the thyristor based portion of this protector component during negative events. This also allows an easier turn on during slow rising power fault events. For all positive disturbances, the fast switching diode connected to earth reference will provide the needed protection.