pef4265 Infineon Technologies Corporation, pef4265 Datasheet - Page 17

• Manufacturer Part Number: pef4265
• Description: Subscriber Line Interface Circuit Enhanced Feature Set
• Manufacturer: Infineon Technologies Corporation

SLIC-E / TSLIC-E
PEF 4265 / PEF 4365
Functional Description
Active Low (ACTL), Active High (ACTH)
These are the regular transmission modes for voiceband. The line-driving section is operated between BGND and
VBATL (ACTL) or VBATH (ACTH).
Active High Resistive (ACTH-R)
The SLIC is operated in Active High state together with the 5 kΩ resistors from TIP to BGND and from RING to
VBATH. This mode is intended to be used for line testing.
Active Ring (ACTR)
V
Utilizing an additional positive battery voltage
, this mode allows balanced ringing of up to 85 Vrms or feeding
HR
of very long telephone lines. In ACTR mode the DC voltage gain is doubled to 60.
High Impedance (HIR, HIT, HIRT)
In these modes each of the line outputs can be programmed to show high impedance. HIT switches off the TIP
buffer, while HIR switches off the RING buffer. The current through the active buffer is still sensed. In the HIRT
mode both buffers show high impedance. The current sensor remains active thus allowing sensor offset calibration
(for test purposes).
2.2
Current Limitation / Overtemperature Protection
In any operating mode the total current delivered by the output drivers is limited to typically 85 mA.
If, however, the junction temperature exceeds 165 °C, the current limit is further reduced to keep the junction
temperature constant.
I
Simultaneously, pin C1 sinks a signalling current
.
therm
Preliminary Data Sheet
17
Revision 2.2, 2008-02-06