Silicon Avalanche Diodes Axial Leaded Telecommunications Transient Voltage Suppressors FOLDBAK™ SERIES Designed to protect sensitive telecommunications electronics from transients which originate from induced lightning, power cross and inductive load switching etc., especially where breakover devices would cause nuisance latch-up. Typical equipment would be: line cards, PABX, modems, multiplexers and NTDs. FEATURES • Foldback characteristics • 2200 watts Peak Power rated with 10/1000µS pulse • 30,000 watts Peak Pulse Power based on 8/20µS • UL 94V-0 flammability classification DESCRIPTION The foldback characteristic of this device eliminates the clamping of the DC current, or the battery, used in telecom systems, so latch-up is eliminated. Latch-up can occur with breakover devices due to the conduction follow-on current supplied by the DC system, after the device has responded to a transient. 0.966 - 1.066 With breakover devices, latch-up will happen more readily as the ambient temperature rises because the holding current values will fall with rising temperature. The Foldbak eliminates this problem while still providing high levels of protection. Min 25.4 4.826 5.207 ABSOLUTE MAXIMUM RATINGS @25˚C case temp (unless otherwise noted) SYMBOL PPP PM (AV) 9.155 9.527 PARAMETER Peak Pulse Current 10x1000µsec 8-20µsec Steady state power dissipation, lead length 9.5mm, TL - 85˚C (note 1) VALUE Units 2,200 20,000 W W 5.0 W Tj Junction temperature -55 to 150 ˚C T stg Storage temperature -55 to 150 ˚C Min 25.4 All dimensions in mm Note 1. Mounted on copper pad area 40mm square Characteristics @25˚C case temp (unless otherwise noted) DEVICE Working Maximum Maximum Minimum Maximum TYPE voltage breakover leakage foldback Peak Pulse Voltage current (Ir) voltage Vfb Current (lpp) (Vr) (Vbo) @ Vr @ Vcl Note 2 volts volts µA volts amps FB120 120 170 1.0 55 170 FB160 160 220 1.0 110 220 Ipp Vfb Ibo Irm Vbo Vrm Note 2. Using 10/1000µS pulse 304 V-I Characteristic w w w. l i t t e l f u s e . c o m