PEB3086 Infineon Technologies, PEB3086 Datasheet - Page 59

• Manufacturer Part Number: PEB3086
• Description: ISDN Subscriber Access Controller
• Manufacturer: Infineon Technologies

3.3.6
The receiver consists of a differential input stage, a peak detector and a set of
comparators. Additional noise immunity is achieved by digital oversampling after the
comparators. A simplified equivalent circuit of the receiver is shown in
Figure 27
The input stage works together with external 10 k W resistors to match the input voltage
to the internal thresholds. The data detection threshold Vref is continuously adapted
between a maximal (Vrefmax) and a minimal (Vrefmin) reference level related to the line
level. The peak detector requires maximum 2 m s to reach the peak value while storing
the peak level for at least 250 m s (RC > 1 ms).
The additional level detector for power up/down control works with a fixed thresholds
VrefLD. The level detector monitors the line input signals to detect whether an INFO is
present. When closing an analog loop it is therefore possible to indicate an incoming
signal during activated loop.
Data Sheet
10 kW
10 kW
SR2
SR1
Receiver Characteristics
Equivalent Internal Circuit of the Receiver Stage
40 kW
40 kW
100 kW
VCM
59
Vrefmin
Description of Functional Blocks
Peak
Detector
Vref+
Vref-
VrefLD
Figure
Negative detected
Positive detected
Level detected
PEB 3086
2003-01-30
ISAC-SX
27.
reccirc