Sidactor Protection Thyristor Products Page 45 SIDACtor Protection Thyristor Products

SIDACtor Protection Thyristors 2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 02/23/17 Another important aspect of TIA-968-B is on-hook impedance, which is affected by transient protection. On-hook impedance is analogous to the leakage current between tip to ring, tip to ground, and ring to ground during various on-hook conditions. "On-hook Impedance Measurements" (next paragraph) outlines criteria for on-hook impedance and is listed as part of the Ringer Equivalent Number (REN). The REN is the largest of the unitless quotients not greater than five; the rating is specified as the actual quotient followed by the letter of the ringer classification (for example, 2B). On-hook Impedance Limitations On-hook impedance measurements are made between tip to ring, tip to ground, and ring to ground. For all DC voltages up to and including 100 V, the DC resistance measured must be greater than 5 M. For all DC voltages between 100 V and 200 V, the DC resistance must be greater than 30 k. The REN values are then determined by dividing 25 M by the minimum measured resistance up to 100 V and by dividing 150 k by the minimum measured resistance between 100V and 200V. On-hook impedance is also measured during the application of a simulated ringing signal. This consists of a 40 V rms through 150 V rms ringer signal at frequencies ranging from 15.3 Hz to 68 Hz superimposed on a 56.5 V dc for a class "B" ringer. During this test, the total DC current may not exceed 3 mA. In addition, the minimum DC resistance measured between tip to ring must be greater than 1600, while the DC resistance measured between the Tip and Ring conductors and Ground must be greater than 100 k. The REN values for the simulated ringing test are determined by dividing the maximum DC current flowing between tip to ring by 0.6 mA, and by dividing 8000 by the minimum impedance value measured. On-hook Impedance Measurements Regulatory Requirements (continued) Part 1: Introduction, definitions, & terminology Part 2: Description & classification of the environment Part 3: Emission & immunity limits Part 4: Testing & measurement techniques Part 5: Installation & mitigation guidelines A summary of Part 4 from IEC 61000-4-2, 61000-4-4, & 61000-4-5 follows. This standard defines test procedures to evaluate equipment ESD resistibility performance. IEC 61000-4-2 Testing and measurement techniques - Electrostatic Discharge (ESD) Immunity test Table 3.30 Test Levels Table 3.31 Test waveform values Figure 3.8 ESD generator schematic Level Contact discharge Air discharge Voltage 1 2 kV 2 4 kV 3 6 kV 8 kV 4 8 kV 15 kV X Special Level Voltage Initial current peak value Rise time Current at 30 nS Current at 60 nS 1 2 kV 7.5A 0.7 to 1 4 A 2A 2 4 kV 15 A 8A 4A 3 6 kV 22.5A 12A 6A 4 8 kV 30A 16A 8A "x" is an open level, to be specified in dedicated equipment specification 50-100 M 330 150 pF dc HV supply Table 3.32 Guidelines for test level selection The test level chosen for a particular application should consider its installation and environmental conditions. Class Relative Humidity as low as Anti-static material Synthetic material Maximum voltage 1 35% * 2 kV 2 10% * 4 kV 3 50% * 8 kV 4 10% * 15 kV IEC 61000-4-2, 4-4 and 4-5 Summary

Previous Page
Next Page