1 of 3 102199 special features zener characteristic with voltage snap?back to protect against esd hits high avalanche voltage, low leakage and low capacitance avoid signal attenuation compatible to all 5v logic families space saving, low inductance tsoc surface mount package on?chip 5 w resistors for isolation at both anode and cathode terminals industrial temperature range symbol and conventions package outline ordering information DS9503p 6-lead tsoc package description this DS9503 is designed as an esd protection device for 1?wire microlan interfaces. in contrast to the ds9502, the DS9503 includes two 5 w isolation resistors on chip. although 5 w are negligible during communication, they represent a high impedance relative to the conducting diode during an esd event. thus, the diode absorbs the energy while the resistors further isolate and protect the circuit at the other side of the package. if used with circuits that already have a strong esd?protection at their i/o port, the esd protection level is raised to more that 27 kv (iec 801?2 reference model). in case of abnormal esd hits beyond its maximum ratings the DS9503 will eventually fail ?short? thus preventing further damage. during normal operation the DS9503 behaves like a regular 7.5v zener diode. when the voltage exceeds the trigger voltage, the i/v characteristic of the device will ?snapback? allowing the same or higher amount of current to flow, but at a significantly lower voltage. as long as a minimum current or voltage is maintained, the device will stay in the ?snapback mode?. if the voltage or the current falls below the holding voltage or holding current, the device will abruptly change to its normal mode and conduct only a small leakage current. vca a ic c tsoc surface mount package 3.7 x 4.0 x 1.5 mm see mech. drawings section 6 1 5 2 4 3 top view DS9503 esd protection diode with resistors www.dalsemi.com side view
DS9503 2 of 3 102199 dc characteristics figure 1 dc characteristics detail drawing figure 2 test pulse waveform figure 3 typical application figure 4
DS9503 3 of 3 102199 physical specifications size see mechanical drawing weight 0.5 grams absolute maximum ratings* operating temperature ?40c to +85c storage temperature ?55c to +125c soldering temperature 260c for 10 seconds continuous dc current through package 80 ma * this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability electrical characteristics (-40 c to +85 c) parameter symbol min typ max units notes leakage current i l 30 100 na 2 avalanche voltage v av 7.4 7.8 v 1,3 trigger voltage v trigger 9.0 9.5 v 1 trigger current i trigger 600 1000 ma holding voltage v hold 5.5 v 1 holding current i hold 30 ma forward voltage (-10 ma) v f -0.7 -0.8 v 4 forward current (-0.7v) i f -10 -100 ma 4 maximum peak current i pp 2.0 a 5 continuous current through diode i cc 80 ma isolation resistance r i 5 w capacitance ( t a =25 c) parameter symbol min typ max units notes junction capacitance (5v) c j5 40 pf 1 junction capacitance (0v) c j0 70 pf 1 thermal resistance parameter symbol min typ max units notes junction to package r q jc 75 k/w junction to ambient r q ja 200 k/w notes: 1. all voltages are referenced from cathode to anode. 2. at 7.0v. 3. at 0.3 m a. 4. typical values at room temperature. 5. see pulse specification.
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