Comtech EF Data SDM-2020 - Manual (Page 162)

SDM-2020 Satellite Demodulator Revision 4
ECL/HSSI Data Interface MN/SDM2020D.IOM
10–10
10.1.4.5 Terrestrial Electrical Characteristics
All signals are balanced, differentially driven, and received at standard 10K/100K ECL
levels. Table 10-6 summarizes the electrical properties of the HSSI interface.
Table 10-6. HSSI General Specifications
General Specifications
Connectors 50-pin mini-D female for EIA-613 (HSSI) data.
Electrical Properties Per EIA-612 (10KH ECL).
TTL/TTL open-collector.
Typical Voltages Levels Differential voltage: ≥ 590 mV, 110Ω load
Input voltage range: -0.5 to -2.0V
Referenced to receiver common.
10.1.4.6 Terrestrial Timing
The nominal interface timing is as follows:
• Clock is 50% duty cycle
• Data/control signals transition on the rising (low to high) edge of the clock
• Data/control signals are stable on the falling (high to low) edge of the clock
Figure 10-7 shows the nominal interface timing.
CLOCK
DATA
SYNC
DVALID
Figure 10-7. Nominal Interface Timing