Switching Gas Discharge Tubes Gas Plasma Voltage Dependent Switches RoHS XT Series The XT Series is a 2-terminal bi-directional, voltage triggered switch designed for Xenon HID 'hot re-strike' circuits such as those found in automobiles. Switching voltages for the devices are fixed depending on the part number selected. The gas plasma trigger technology offers very fast switching speeds, resulting in significantly better di/dt values when compared to silicon based SIDAC devices. Due to the high switching voltage of the devices, step-up transformer sizes and specifications can be reduced saving cost, size and weight. Features • RoHS compliant • 2 terminal configuration. • Very high switching speed once switching voltage has been reached, resulting in high di/dt to be generated enabling the best performance to be extracted from ignition transformers. • High lifetime and stability. • Switching performance is virtually unaffected by changes in ambient temperature. • Tape and Reel to EIA 481-1 Applications • This product is optimised for Xenon HID ‘Hot re-strike’ circuits which require a very high number of operations at high current levels. The switching time is typically 10nS for the best possible efficiency. XT xxx SM. 8 6 +0.20 - 0.20 +0.20 - 0.20 60.0 +4 XT xxx A. Dimensions in mm ORDERING INFORMATION XT A VBO Package Type Mechanical Specifications: Weight (ballast ciruit only): 1.42g (0.049oz.) Materials: Electrode Base: Copper alloy Device Marking: Packaging A= Axial lead tape and reel SM= Surface Mount 320 w w w. l i t t e l f u s e . c o m Electrode Plating material: Bright Sn Body: Ceramic Littelfuse ‘LF’ marking, voltage and product code Switching Gas Discharge Tubes Gas Plasma Voltage Dependent Switches XT Series Device Ratings and Specifications Max Ignition (V) VT @ 5A (V) IDRM (2) (A) IBO (2) (mA) CO (4) (pF) VBO to VT (nS) RS (M) XT350 297 – 403 463 15 1.0 5 1.5 25 >1 XT600 510 – 690 750 15 1.0 5 1.5 25 >1 XT800 680 – 920 1000 15 1.0 5 1.5 25 >1 7 SWITCH GAS DISCHARGE TUBES VBO(1) (7) Part Number Electrical Life: Switching Cycles (5) ………………………………………………………… 150,000 Maximum Ratings: Max Switching Frequency(6) ………………………………………………………. 400 Hz Storage Temperature TSTG ……………………………………………………… -40 - +150˚C Operating Temperature ……………………………………………………… -40 - +150˚C Notes: (1) Measured on recommended test circuit (fig 1.) (2) Measured @ 100 Volts DC (3) Current required for transition to on-state (4) Measured @ 1 MHz, zero Volt bias (5) Measured on recommended test circuit (fig 2.) (6) Duty Cycle: 1sec on, 10 sec off. (7) Will retain these limits during life cycle Definitions: VBO – Breakover Voltage VT @ 5A – Nominal Off-state Voltage at 5A IDRM – Off-state Current IBO – Nominal Breakover Current Co - Max Capacitance VBO to VT – Max switching time from VBO to VT R1 R1 L V V C2 C2 XT device XT device Fig 1. Recommended breakover voltage test circuit V: open circuit DC voltage =500 (1000V for 600 and 800Vparts) R1 =51KΩ C1 =220nF Discharge current =10 mAmps ( approx ) Fig 2. Recommended life test circuit V: open circuit DC voltage =500 (1000V for 600 and 800V parts) R1 =10KΩ C1 =680nF L =0.5µH Discharge current =500Amps ( approx ) w w w. l i t t e l f u s e . c o m 321