PEB3265 Infineon Technologies Corporation, PEB3265 Datasheet - Page 123

• Manufacturer Part Number: PEB3265
• Description: (PEB326x / PEB426x) Dual Channel Slicofi-2 / Slic Duslic
• Manufacturer: Infineon Technologies Corporation

Preliminary
4.8.2.9
The DC loop resistance can be determined by supplying a constant DC voltage V
to the Ring- and Tip line and measuring the DC loop current via IT pin. The following
steps are necessary to accomplish this:
• Program a certain ring offset voltage RO1, RO2, RO3 (see DuSLICOS DC Control
• Select ring offset voltage RNG-OFFSET[1:0] in register LMCR3 either to 01, 10 or 11.
• Choose an operation mode, either Active High (ACTH) or Ring Pause.
• Select the DC path for levelmeter by setting the bits LM-SEL[3:0] in register LMCR2
• The transversal current can be determined by reading the levelmeter result registers
• Based on the known constant output voltage V
In order to increase the accuracy of the result, either the current offset can be
compensated or the measurement can be done differentially. The latter one eliminates
the current- and voltage offsets.
Figure 49
Figure 49
Data Sheet
Parameter 2/3).
If 00 is selected, the DC regulation would be still active and would not allow resistance
measurement.
to 0101 (DC current on IT).
LMRES1, LMRES2.
RNG-OFFSET[1:0]) and the measured I
calculated. It should be noted, that the calculated resistance includes also the onboard
resistors R
R
I
LINE
LINE
shows an example circuit for resistance measurement:
Loop Resistance Measurements
PROT
Example Resistance Measurement
R
R
LINECARD
PROT
PROT
* DC Offset Voltage
according to
RNG-OFFSET[1:0]
+ R
and R
+ R
V
STAB
STAB
TR,DC
*
STAB
SLIC-E/-E2/-P
.
123
TRANS
line current sense signal to
be measured
DCP
DCN
IT
IL
TR,DC
current, the resistance can be
duslic_0011_measurement_tip_ring.emf
(DC voltage according to
Operational Description
SLICOFI-2
2000-07-14
DuSLIC
TR,DC