C650-180-WH_15 Datasheet, PDF (6/6 Pages) Bourns Electronic Solutions – TBU High-Speed Protectors

C650 and C850 Series TBU^® High-Speed Protectors
Reference Application
The C-series devices are general protectors that can be used in a variety of applications. The basic operation of the device will be
demonstrated using the single line application shown in the figure below. The test circuit was subjected to a 1000 V, 10/700 µs surge
waveform. The devices used were the TBU-C850-100-WH and a 2031-42T-SM-RPLF GDT (OVP) with a 10 ohm resistor for the load
impedance.
Line
OVP _{TBU® Device}
ZLOAD
General Application Circuit
The graph below shows the waveforms for the voltage across the overvoltage protector (GDT) and the current through the TBU^®
device. As the input line voltage increases, the current through the TBU^® device increases rapidly until the trip current is reached. Due
to finite reaction time for fast transients, the peak level may exceed the low frequency data sheet maximum for a very short period,
typically ~100 ns. After this initial overshoot, the TBU^® device will transition to the protected state, setting the current to the nominal
current limiting level (~150 mA for this example). The TBU^® device will then reduce the current down it to its very low quiescent level
of 1 mA, typically. As the input line voltage increases to about 500 V, the GDT is triggered, reducing the input line voltage to a very low
level which prevents the TBU^® device from being subjected to a voltage level which exceeds its maximum rating (850 V in this
example). The TBU^® High-Speed Orotector and the GDT will remain in these states until the surge ends, which is about 700 µs later
in this example. Only the first 4 µs of the surge are shown in the graph. For surges or AC voltages below the GDT breakover voltage,
the GDT will not activate, and the TBU^® device will stay in the protecting mode, blocking high voltages from the protected equipment.
900
800
700
600
500
400
300
200
100
0
100
0
0.5 1
TBU^® Device Current
GDT Voltage
1.5
2 2.5
3 3.5
1000
800
600
400
200
0
-200
-400
-600
-800
-1000
4
Time (µs)
TBU-C850-100-WH Response to a 1000 V, 10/700 µs Surge
REV. 09/15
“TBU” is a registered trademark of Bourns, Inc. in the United States and other countries.
Specifications are subject to change without notice.
The device characteristics and parameters in this data sheet can and do vary in different applications and actual device performance may vary over time.
Users should verify actual device performance in their specific applications.