LIGHTNING PROTECTION
DINn inputs are designed to survive lightning induced transients as defined by RTCA DO160E, Section 22 Cat A3 and B3,
Waveforms 3, 4, and 5A. They can withstand Level 3 stress (see waveforms below) with only the external 3 kΩ series resistor
for current limiting. Protection for higher stress levels can be achieved with the addition of transient voltage suppressor (TVS)
devices at the DINn pins. Select TVS clamp voltage <450 V. The 3 kΩ series resistors limit the TVS surge current.
V
V/I
Peak
25% to 75%
of Largest Peak
T1 = 6.4 us
T2 = 70 us
50%
0
t
50%
F = 1 MHZ and 10 MHZ
0
t
T1
T2
Figure 8 Voltage / Current Waveform 3
Figure 9 Voltage Waveform 4
V/I
Peak
T1 = 40 us
T2 = 120 us
Level 3 Waveform Source Impedance characteristics:
·
·
·
·
Waveform 3 Voc/Isc = 600 V / 24A => 25 Ω
Waveform 4 Voc/Isc = 300 V / 60 A => 5 Ω
Waveform 5A Voc / Isc = 300 V / 300 A => 1 Ω
Waveform 5A Voc / Isc = 500 V / 500 A => 1 Ω
50%
0
t
T1
T2
Figure 10 Current/Voltage Waveform 5A
©2018 Device Engineering Inc.
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DS-MW-01184-01 Rev. E
06/25/2018
DEIAZ [ Device Engineering Incorporated ]
