TISP4219H3BJ 查看數據表（PDF） - Bourns, Inc
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产品描述 (功能)
生产厂家
TISP4219H3BJ
Bourns, Inc
TISP4219H3BJ Datasheet PDF : 15 Pages
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TISP4xxxH3/M3BJ Series for LCAS Protection
LCAS Switch Ratings
When a switch is in the off state, the maximum withstand voltage may be set by the switch itself or by the control line to the switch. At 25°C,
the switch terminal to ground voltage rating for all the switches is ±320 V. Switches SW1 to SW3 are bidirectional MOS types and can
withstand ±320 V between terminals. Switch SW4 is a bidirectional thyristor which is rated at ±465 V between terminals.
Overcurrents as well as overvoltages occur on telephone lines. In the on state, the thyristor switch, SW4, is capable of withstanding high levels
of current overload. For currents above about 200 mA, the MOS switches, SW1 to SW3, will go into a current limited condition. This will cause
the voltage to rise across the switch and large amounts of power to be developed. In the longer term, this power loss increases the overall chip
temperature. When the temperature exceeds about 125 °C, thermal shutdown occurs and the switches are set to the off state. Without power
loss, the LCAS will cool. Eventually, the thermal trip will reset, setting the switches back in the high power loss condition again. The cycle of
temperature increase, thermal shutdown, temperature decrease and switch re-activation will continue until the overcurrent ceases.
TISP4125M3
OR
R1 TISP4125H3
TIP
RING
RELAY
SLIC
RELAY
SLIC
Th1
SW3
SW1
Th3
RING
Th2
R2 TISP4219M3
OR
TISP4219H3
SW4
Th4
SW2
Vbat
AI4XAR
GROUND-BACKED RINGING
SW5 AS SHOWN
+√2xV RING
TIP
WIRE
0
VBAT
RING
WIRE
-√2xV RING
R2
R1
± √2xV RING
VBAT
SW5b SW5a
RING
GENERAT OR
BATTERY-BACKED RINGING
SW5 OPERATED
VBAT + √2xV RING
TIP
WIRE
0
VBAT
RING
WIRE
VBAT - √2xV RING
Figure 13. LCAS Shown with Switch Breakdown Limits
Equivalent Circuit
Figure 13 shows the LCAS switch voltage ratings as breakdown diodes, which must not be allowed to conduct. Each switch has three diodes;
one between poles and the other two from each pole to ground. At 25 °C, switches SW1 through to SW3 have breakdown diode voltages of
±320 V. Switch SW4 has breakdown diode voltage values of ±465 V for the one between poles and ±320 V for the two diodes connected to
ground. Note that only protection to ground is required, as in the limit, the inter-switch voltage limitation of ±640 V is the same as the switch to
ground limitation of +320 V and -320 V in both polarities.
JUNE 2001 – REVISED FEBRUARY 2005
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
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