peb2025 ETC-unknow, peb2025 Datasheet - Page 9

• Manufacturer Part Number: peb2025
• Description: Isdn Exchange Power Controller
• Manufacturer: ETC-unknow

PEB 2025
If overload is once detected, every exceeding of the current limits will turn off the line driver until
t
is reached. The time dependent current limiting circuit will not be reseted if once overload is
OFF4
detected, even if the feeding current drops below
I
until
t
is reached.
max
OFF4
If pin CLC is connected to GND the time and current dependent turn off characteristic is disabled
and the IEPC limits the driver current.
Automatic Restart
In connection with the time-dependent-current-limitation, the IEPC offers a programmable
automatic restart mode (see digital part).
I
I
t
C
If overload is detected (
) at
, the IEPC starts charging the external capacitor
.
aFi
max
0
Ti
Automatic restart enabled: If the line driver has been switched off due to the time dependent turn off
C
t
characteristic,
will not be discharged by the IEPC. If
is reached the line driver restarts
Ti
OFF4
automatically. So the time difference between turn off and automatic restart is variable and depends
on the moment of turn off.
t
Autorestart disabled: If
is reached or if the line driver has been switched off due to the time
OFF4
C
dependent turn off characteristic,
will be discharged by the IEPC. During the discharge time of
Ti
C
, every restart of line i via microprocessor interface will be ignored by the IEPC.
Ti
(With
C
= 10 F the maximum discharge time is 10 ms.)
Ti
Temperature Shut-Off
The temperature of each line driver is monitored separately. If the temperature of one line driver
exceeds the shut-off temperature (approx. 120 ˚C), the transmission line will turn off. The shut-off
temperature of the other three line drivers will be increased by approx. 25 ˚C.
Open Loop Detection
The IEPC offers an easy method to detect open loops. If the line driver aFi is in the OFF state a
constant current source (approx. 100 A) feeds the output aFi. In case of open loop (figure 5) the
voltage at output aFi rises up to 3 V.
Semiconductor Group
9