RPT-86

The RPT-86 has the following features including Low Power Consumption (56mW);Single-Supply Operation;Wide Data Rate Range <100kbit/s to >3Mbit/s;Dual ALBO Diodes; Dynamic Range >50dB.

The RPT-86 is monolithic repeater circuits containing all the active functions required in regenerative PCM repeaters. These devices automatically adjust gain to optimize signal levels, determine if a pulse is present, and re-transmit the reconstructed pulses. The RPT-86 operate at data rates from under 100kbit/s to over 3Mbit/s and are compatible with T1 (1.544MbiVS), CEPT/E1(2.048MbiVs), and T1 C (3.152MbiUs) systems.A key feature of the RPT-86 repeater is the ability to operate on a single supply of 5.6V with a typical quiescent supply current of only 10mA. In addition, the RPT-86 has two Automatic Line Build-Out (ALBO) diodes coupled with a high-gain preamplifier that allows for a dynamic input signal range exceeding 50dB.The preamplifier has typically 5MHz,-3dB bandwidth.  Its open-loop gain-phase frequency response is shown in Figure 1 .In order to operate the preamplifier under a stable condition, some amount of external feedback is necessary to control the frequency response.  The open-loop frequency response suggests that the feedback network must have 40d8 attenuation or more at 20MHz and above to ensure stability.

The data Detector thresholds RPT-86 are set at 50% of the Peak levels for maximum noise immunity. The outputs of these comparators contain the digital data and are presented to the output R-S flip-flops. The Clock Detector thresholds are set at 70% of the Peak levels. When the Clock thresholds are reached, the comparators send a synchronization pulse to the on-board oscillator to lock its frequency and phase to that of the incoming signal.The peak detectors trip when the signal exceeds the peak thresholds. Peak Detector outputs are used to perform an AGC function to maintain a constant preamp peak output level.The incremental impedance of the diode-connected NPN transistor used as the ALSO diode is dependent on the DC bias current flowing through it.