CLP200M Datasheet, PDF (5/21 Pages) STMicroelectronics – OVERVOLTAGE AND OVERCURRENT PROTECTION FOR TELECOM LINE

2.3 Ringing mode
Fig. 4 : Switching by voltage during ringing mode.
Fuse
ILG
TIP
R sense
TIPL
TIPS
1
Over current
detector
1/2 CLP200M
Rp
2
OR
SW3 SW1
Overvoltage
VLG
detector
Overvoltage
reference
(+/- 215 V)
FS
GND
CLP200M
ILG
A1
-215
2
1
+215
VLG
3
In ringing mode (Ring relay in position 2), the only
protectiondevice involved is the CLP200M.
In normal conditions, the CLP200M operates in re-
gion 1 of A1 curve, and is idle.
If an overvoltage occuring between TIP (or RING)
and GND reaches the internal overvoltage refe-
rence (+/- 215V), the CLP200M acts and the line is
short-circuited to GND. At this time the operating
point moves to region 2 for positive surges (region
3 for negative surges). Once the surge current dis-
appears, the device returns to its initial state (re-
gion 1).
For surges occuring between TIP and RING, the
CLP200M acts in the same way. This means that
the CLP200M ensures a tripolar protection.
When used alone, the CLP200M acts at the inter-
nal overvoltage reference level (+/- 215V). Further-
more, it is possible to adjust this threshold level to
.a lower voltage by using :
up to 4 fixed external voltage reference (V_Z1 to
VZ4) (see fig.5a).
Fig. 5a : Method to adjust the reference voltage.
Fuse
TIP
R sense
TIPL
TIPS
Overcurrent
detector
OR
SW3 SW1
FS
SW4 SW2
OR
Overvoltage
detector
Overvoltage
reference
(+/- 215 V)
Overvoltage
detector
Overvoltage
reference
(+/- 215 V)
GND
RING
Fuse
Overcurrent
detector
RINGL
R sense
RINGS
®
1
Rp
2
VZ1
VZ2
VZ3
VZ4
1
Rp
2
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