TISP7125F3, TISP7150F3, TISP7180F3, TISP7240F3, TISP7260F3,
TISP7290F3, TISP7320F3, TISP7350F3, TISP7380F3
TRIPLE BIDIRECTIONAL THYRISTOR OVERVOLTAGE PROTECTORS
MARCH 1994 - REVISED MARCH 2000
longitudinal balance
®
Figure 35 shows a three terminal TISP with its equivalent “delta” capacitance. Each capacitance, C
, C
RG
TG
and C , is the true terminal pair capacitance measured with a three terminal or guarded capacitance bridge.
TR
If wire R is biased at a larger potential than wire T then C > C . Capacitance C is equivalent to a
TG
RG
TG
capacitance of C
in parallel with the capacitive difference of (C - C ). The line capacitive unbalance is
RG
TG RG
due to (C - C ) and the capacitance shunting the line is C + C /2 .
TG
RG
TR
RG
Figure 35.
All capacitance measurements in this data sheet are three terminal guarded to allow the designer to
accurately assess capacitive unbalance effects. Simple two terminal capacitance meters (unguarded third
terminal) give false readings as the shunt capacitance via the third terminal is included.
P R O D U C T
I N F O R M A T I O N
19
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