ISL4489E Datasheet, PDF (6/12 Pages) Intersil Corporation – Low Power, High Speed and Slew Rate Limited, Full Duplex, RS-485/RS-422 Transceivers

Test Circuits and Waveforms
ISL4489E, ISL4491E
V_CC ^DE
DI
Z
D
Y
R
V_OD
R
V_OC
FIGURE 1. DRIVER V_OD AND V_OC
DE
V_CC
DI
SIGNAL
GENERATOR
Z
D
Y
C_L = 100pF
R_DIFF
C_L = 100pF
DI
OUT (Y)
OUT (Z)
1.5V
t_PLH
50%
t_PHL
50%
3V
1.5V
0V
t_PHL
50%
V_OH
V_OL
t_PLH
50%
V_OH
V_OL
DIFF OUT (Y - Z)
90%
10%
t_R
90%
10%
t_F
+V_OD
-V_OD
SKEW = |t_PLH (Y or Z) - t_PHL (Z or Y)|
FIGURE 2A. TEST CIRCUIT
FIGURE 2B. MEASUREMENT POINTS
FIGURE 2. DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES
6
FN6074.2