ISL8488E, ISL8489E, ISL8490E, ISL8491E
Test Circuits and Waveforms
VCC DE
DI
Z
D
Y
R
VOD
R
VOC
FIGURE 1. DRIVER VOD AND VOC
DE
VCC
DI
SIGNAL
GENERATOR
Z
D
Y
CL = 100pF
RDIFF
CL = 100pF
DI
OUT (Y)
OUT (Z)
1.5V
tPLH
50%
tPHL
50%
3V
1.5V
0V
tPHL
50%
VOH
VOL
tPLH
50%
VOH
VOL
DIFF OUT (Y - Z)
90%
10%
tR
90%
10%
tF
SKEW = |tPLH (Y or Z) - tPHL (Z or Y)|
FIGURE 2A. TEST CIRCUIT
FIGURE 2B. MEASUREMENT POINTS
FIGURE 2. DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES
+VOD
-VOD
6
FN6073.4
July 26, 2007