LMH0202 Datasheet, PDF (5/6 Pages) National Semiconductor (TI) – Dual SMPTE 202M / 259M Serial Digital Cable Driver

Device Operation (Continued)
DVB-ASI APPLICATIONS
The dual differential inputs of the LMH0202 may be exter-
nally routed to a single differential input as shown in Figure
2. This provides a solution for DVB-ASI applications where
two non-inverted outputs are needed.
OUTPUT INTERFACING
The LMH0202 uses current mode outputs. Single-ended
output levels are 800 mV_P-P into 75Ω AC-coupled coaxial
cable (with R_REF = 750Ω). Output level is controlled by the
value of the resistor connected between the R_REF pin and
V_CC.
The R_REF resistor should be placed as close as possible to
the R_REF pin. In addition, the copper in the plane layers
below the R_REF network should be removed to minimize
parasitic capacitance.
OUTPUT SLEW RATE CONTROL
The LMH0202 output rise and fall times are selectable for
either SMPTE 259M or SMPTE 292M compliance via the
SD/HD pin. For slower rise and fall times, or SMPTE 259M
compliance, SD/HD is set high. For faster rise and fall times,
or SMPTE 292M compliance, SD/HD is set low.
20173103
FIGURE 2. Single Differential Input for DVB-ASI
5
www.national.com