TISP61089A
DUAL FORWARD-CONDUCTING P-GATE THYRISTORS
PROGRAMMABLE OVERVOLTAGE PROTECTORS
JUNE 1999
OVER-
CURRENT
PROTECTION
TIP
WIRE
R1a
RING/TEST
PROTECTION
Th1
TEST
RELAY
RING
RELAY
SLIC
RELAY
S3a
SLIC
PROTECTOR
Th4
SLIC
S1a
Th3
S2a
RING
WIRE
R1b
Th2
TISP
3xxxF3
OR
7xxxF3
S3b
S1b
S2b
Th5
TISP
61089A
C1
220 nF
V
BAT
TEST
EQUIP-
MENT
RING
GENERATOR
AI6XAJA
Figure 7. TYPICAL APPLICATION CIRCUIT
Relay contacts 3a and 3b connect the line conductors to the SLIC via the TISP61089A protector. The
protector gate reference voltage comes from the SLIC negative supply (V
BAT
). A 220 nF gate capacitor
sources the high gate current pulses caused by fast rising impulses.
LSSGR 1089
GR-1089-CORE, “1089”, covers electromagnetic compatibility and electrical safety generic criteria for US
network telecommunication equipment. It is a module in Volume 3 of LSSGR (LATA (Local Access Transport
Area) Switching Systems Generic Requirements, FR-NWT-000064). In 1089 surge and power fault immunity
tests are done at two levels. After first-level testing the equipment shall not be damaged and shall continue to
operate correctly. Under second level testing the equipment shall not become a safety hazard. The equipment
is permitted to fail as a result of second-level testing. When the equipment is to be located on customer
premises, second-level testing includes a wiring simulator test, which requires the equipment to reduce the
power fault current below certain values.
The following clauses reference the 1089 section and calculate the protector stress levels. The TISP61089A
is specified for use with a 40
Ω
series resistor. This resistor value will ensure that the TISP61089A survives
second level surge testing. Values down to 25
Ω
may be used if some second level surge failure is
acceptable. All the tabulated values are for a series resistance of 40
Ω.
Peak current values for a 25
Ω
series
resistor are covered in the clause text.
The values of protector current are calculated from the open circuit generator voltage divided by the sum of
the total circuit resistance. The total circuit resistance is the sum of the generator fictive source resistance and
the TISP61089A series resistor value. Most generators have multiple outputs and each output connects to an
individual line conductor. For those generators that have a single output, each conductor will have an effective
generator fictive source resistance of n times the generator fictive source resistance, where n is the number of
conductors simultaneously tested.
PRODUCT
8
INFORMATION
POINN [ POWER INNOVATIONS LTD ]
