Tvs Diode Array Spa Diodes Page 24 TVS Diode Array SPA Diodes Catalog

2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 02/23/17 TVS Diode Arrays (SPA Diodes) General Purpose ESD Protection - SP721 Series Peak Transient Current Capability of the SP721 The peak transient current capability rises sharply as the width of the current pulse narrows. Destructive testing was done to fully evaluate the SP721's ability to withstand a wide range of peak current pulses vs time. The circuit used to generate current pulses is shown in Figure 4. The test circuit of Figure 4 is shown with a positive pulse input. For a negative pulse input, the (-) current pulse input goes to an SP721 'IN' input pin and the (+) current pulse input goes to the SP721 V- pin. The V+ to V- supply of the SP721 must be allowed to float. (i.e., It is not tied to the ground reference of the current pulse generator.) Figure 5 shows the point of overstress as defined by increased leakage in excess of the data sheet published limits. The maximum peak input current capability is dependent on the ambient temperature, improving as the temperature is reduced. Peak current curves are shown for ambient temperatures of 25C and 105C and a 15V power supply condition. The safe operating range of the transient peak current should be limited to no more than 75% of the measured overstress level for any given pulse width as shown in the curves of Figure 5. Note that adjacent input pins of the SP721 may be paralleled to improve current (and ESD) capability. The sustained peak current capability is increased to nearly twice that of a single pin. + - VOLTAGE PROBE + - R 1 ~ 10 TYPICAL V X V X ADJ. 10V/ATYPICAL R 1 (-) (+) C1 ~ 100 F C1 VARIABLE TIME DURATION CURRENT PULSE GENERATOR 1 2 3 4 8 7 6 5 V+ IN V- SP721 CURRENT SENSE 0.001 0.01 0.1 1 10 7 6 5 4 3 2 1 0 100 1000 CAUTION: SAFE OPERATING CONDITIONS LIMIT THE MAXIMUM PEAK CURRENT FOR A GIVEN PULSE WIDTH TO BE NO GREATER THAN 75% OF THE VALUES SHOWN ON EACH CURVE. V+ TO V-SUPPLY = 15V T A = 25C T A = 105C PULSE WIDTH TIME (ms) PEAK CURRENT (A) Showing the Measured Point of Overstress in Amperes vs pulse width time in milliseconds Figure 5: SP721 Typical Single Peak Current Pulse Capability Figure 4: Typical SP721 Peak Current Test Circuit with a Variable Pulse Width Input

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