http:// www.sirectsemi.com low capacitance surface mount tvs diodes features ? four ultra-low input capacitance ( 1 pf typ.) esd rail-to-rail protection diodes ? esd iec 61000-4-2 level 4, 8kv contact discharge compliant protection ? low voltage clamping due to integrated zener diode ? compact sot-23-6 package application general-purpose downstr eam esd protection high frequency analog signals and high-speed serial data transmission for ports inside: ? pc-/notebook usb2.0/ieee1394 ports ? cellular phone and pcs mobile handsets ? dvi interfaces ? cordless telephones ? wireless data (wa n/lan) systems ? pdas maximum ratings rating symbol min max unit dc input voltage range v i/o 0 +5.5 volts electrostatic discharge, all pi ns (iec 61000-4-2, level 4, contact) esd -8 +8 kilovolts device storage temperature t stg -55 +125 o c electrical characteristics t c = 25 o c unless otherwise specified parameter test conditions symbol min typ max unit pin capacitance to ground, pins 1, 3, 4, 6 vdc = 0v; f = 1 mhz pin 5 = +3.0v c i/o - 1.0 - pf diode reverse leakage current, pins 1, 3, 4, 6 to ground v = +3.0v i lkg - - 100 na zener diode capacitance to ground, pin 5 to 2 vdc = 0v; f = 1 mhz pin 5 = +3.0v c zener - 40 - pf zener diode breakdown voltage, pin 5 to 2 i = 1ma v br i/o 6 - 9 v forward voltage v f - 0.7 - v august 2007 / rev.5 the L054BT26 devices are low-capacitance transient voltage suppressors designed to protect components which are connected to data and transmission lines from over voltages caused by electrostatic discharge (esd), electrical fast transients (eft), and induced lightning. schematic & pinning (sot23-6) circuit diagram e l e c t r o n i c L054BT26
http:// www.sirectsemi.com L054BT26
http:// www.sirectsemi.com application information 1.0 four high-speed data lines protection the L054BT26 tvs diode is designed to protect up to four data lines from transi ent over-voltages by clamping them to a fixed reference. when the vo ltage on the protected line(s) exceeds the reference voltage (plus diode v f ), the steering diodes are forward biased, conducting the transient current away from the protected circuitry. the data lines are c onnected to pins 1, 2, 4 and 6. the negative reference (ref1) is connected to pin 2 (this pin should be connected directly to the ground plane on the pcb for best results) . the path length is kept as short as possi ble to minimize parasitic inductance. the positive reference (ref2) is connected to pin 5. the typical options for connecting the positive reference are as follows: a. data line and power supply protection using v cc as reference to protected data lines and the power line, connect pi n 5 directly to the positive supply rail (vcc). in this configuration, the data lines are refer enced to the supply voltage. the internal tvs diode prevents over-voltage on the supply rail. L054BT26
http:// www.sirectsemi.com application information (continued) b. data line protection with bi as and power supply isolation resistor the L054BT26 can be isolated from the power supply by adding a series resistor between pin 5 and v cc (a resistor value of 100k ? is recommended) . the internal tvs and steering diodes remain biased, providing the advance of even lower capacitance. c. data line protection usin g internal tvs diode as reference in applications where no positive supply reference is av ailable, or complete supply isolation is desired, the internal tvs may be used as the reference. in this case, pin 5 is not used. the steering diodes will begin to conduct when the voltage on the protect ed line exceeds the working voltage of the tvs (plus one diode drop). L054BT26
http:// www.sirectsemi.com application information (continued) 2.0 universal serial bus (usb) esd protection the L054BT26 can be used to protect the usb ports on mobile phones, monitors, pcs, peripherals and other portable systems (please refer to schematic diagram below) . in typical applications, the voltage bus (v bus ) of usb ports are connected to the power pi n (pin 5) of the device. each data line (d+/d-) of the usb ports is connected to the esd protection pin of the device. when an electrostatic discharge (esd) pulse appears on the data line, the esd pulse current will be conducted by the L054BT26 away from the usb controller chip. in addition, the esd pulse current can also be conducted by the device away from t he usb controller chip when the esd voltage pulse appears on the voltage bus (v bus ) of any of the usb ports. ther efore, the data lines (d+/d-) and voltage bus (v bus ) of the two usb ports are comp lementally protected with the L054BT26 device. typical universal serial bus 2.0 se rial application of the L054BT26 L054BT26
http:// www.sirectsemi.com application information (continued) 3.0 audio interface esd protection another typical application of the L054BT26 is esd protection of the right/left channel and tmc terminals of an audio interface. referring to the schematic diagram below, the right and left channels of the audio connector are connected to the esd protection pins (such as pin 1 and pin 6) of the L054BT26 . in addition, the tmc terminals of t he audio connector are also connected to the esd protection pins (such as pin 3 and pin 4) of t he device. regarding the power pin (pin 5) of the device, this should be directly connected to the v dd power supply. in this configuration, when an electrostatic discharge (esd) voltage pulse appears on the right or left channel or tmc terminals of audio connector, the esd pulse current will automatically be discharged by by the L054BT26 . therefore, the right/left c hannel and tmc terminals of the audio chip are complementally protected with an L054BT26 device. typical audio interface application of the L054BT26 L054BT26
http:// www.sirectsemi.com application information (continued) 4.0 other applications dvi/hdmi digital single link esd protection t1/e1/ethernet esd protection L054BT26
http:// www.sirectsemi.com package drawing marking codes part number marking code L054BT26 5v4 L054BT26 sirectifier global corp., delaware, u.s.a. u.s.a.: sgc@sirectsemi.com france: ss@sirectsemi.com taiwan: se@sirectsemi.com hong kong: hk@sirectsemi.com china: st@sirectsemi.com ? thailand: th@sirectsemi.com philippines: aiac@sirectsemi.com belize: belize@sirectsemi.com
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