HD26C31 Datasheet, PDF (12/15 Pages) Hitachi Semiconductor – Quadruple Differential Line Drivers With 3 State Outputs

HD26C31
I_OH
Y "H"
R_T
"L"
Z
I_OL I_IN (Receiver)
Figure 3 Example of Driver Use-1
I_OH
Y "H"
R_T
"L" ^RT
Z
I_IN (Receiver)
Figure 4 Example of Driver Use-2
Output Voltage vs. Termination Resistance
10
V_OH(Y)
1
0.1
"H"
0.01
0.001
10 20
V_OL(Z)
50 100 200 500 1k 2k 5k 10k 20k 50k
Termination Resistance R_T (Ω)
Y
R_T
R_T
V_OH
Z
V_OL
GND
Figure 5 Termination Resistance vs. Output Voltage Characteristics
A feature of termination implemented as shown in figure 7 is that power dissipation is low when the duty of
the transmitted signal is high.
However, care is required, since if R_T is sufficiently small, when the output on the pulled-up side goes high,
a large current will flow and the output low level will rise.
Figure 8 shows the output characteristics when termination resistance R_T is varied.
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