61089B View Datasheet(PDF) - Bourns, Inc
Part Name
Description
Manufacturer
61089B Datasheet PDF : 20 Pages
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TISP61089B High Voltage Ringing SLIC Protector
APPLICATIONS INFORMATION
Operation of Ringing SLICs using Multiple Negative Voltage Supply Rails
Figure 4 shows a typical powering arrangement for a multi-supply rail SLIC. VBATL is a lower (smaller) voltage supply than VBATH. With supply
switch S1 in the position shown, the line driver amplifiers are powered between 0 V and VBATL. This mode minimizes the power consumption
for short loop transmission. For long loops and to generate ringing, the driver voltage is increased by operating S1 to connect VBATH. These
conditions are shown in Figure 5.
SLIC
0V
LINE
S1
VBATL
VBATH
0V
VBATL
LINE
DRIVERS
SUPPLY
SWITCH
AI6XCC
Figure 4. SLIC with Voltage Supply Switching
0V
VSLICG
VPKRING /2
VDCRING
VPKRING /2
VPKRING/2
VPKRING/2
0V
VBATH
SHORT LOOP
VSLICH
LONG LOOP
VBATH
RINGING
Figure 5. Driver Supply Voltage Levels
AI6XCD
VBATH
Conventional ringing is typically unbalanced ground or battery backed. To minimize the supply voltage required, most multi-rail SLICs use
balanced ringing as shown in Figure 5. The ringing has d.c., VDCRING, and a.c., VPKRING, components. A 70 V r.m.s. a.c. sinusoidal ring signal
has a peak value, VPKRING, of 99 V. If the d.c. component was 20 V, then the total voltage swing needed would be 99 + 20 = 119 V. There are
internal losses in the SLIC from ground, VSLICG, and the negative supply, VSLICH. The sum of these two losses generally amounts to a total of
10 V. This makes a total, VBATH, supply rail value of 119 + 10 = 129 V.
In some cases a trapezoidal a.c. ring signal is used. This would have a peak to r.m.s ratio (crest factor) of about 1.25, increasing the r.m.s. a.c.
ring level by 13 %. The d.c. ring voltage may be lowered for short loop applications.
OCTOBER 2000 - REVISED JULY 2008
Specifications are subject to change without notice.
Customers should verify actual device performance in their specific applications.
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