ISL32470E Datasheet, PDF (10/19 Pages) Intersil Corporation – Fault Protected, Extended Common Mode Range, RS-485/RS-422 Transceivers

ISL32470E, ISL32472E, ISL32475E, ISL32478E
Test Circuits and Waveforms (Continued)
3V
DI
1.5V
1.5V
0V
DE
V_CC
DI
SIGNAL
GENERATOR
Z
D
Y
C_D
R_D
OUT (Z)
OUT (Y)
t_PLH
90%
DIFF OUT (Y - Z)
10%
t_R
t_PHL
V_OH
V_OL
90%
10%
t_F
+V_OD
-V_OD
FIGURE 4A. TEST CIRCUIT
SKEW = |t_PLH - t_PHL|
FIGURE 4B. MEASUREMENT POINTS
FIGURE 4. DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES
SIGNAL
GENERATOR
PARAMETER
t_HZ
t_LZ
t_ZH
t_ZL
t_ZH(SHDN)
t_ZL(SHDN)
DE
DI
Z
D
Y
110Ω
C_L
V_CC
SW ^GND
OUTPUT
RE
DI SW C_L (pF)
Y/Z
X
1/0 GND 50
Y/Z
X
0/1 V_CC
50
Y/Z
0 (Note 9) 1/0 GND 100
Y/Z
0 (Note 9) 0/1 V_CC 100
Y/Z
1 (Note 12) 1/0 GND 100
DE
(Note 11)
t_ZH, t_ZH(SHDN)
(Note 11)
OUT (Y, Z)
t_ZL, t_ZL(SHDN)
(Note 11)
OUT (Y, Z)
1.5V
3V
1.5V
0V
t_HZ
OUTPUT HIGH
2.3V
V_OH - 0.5V ^VOH
0V
t_LZ
2.3V
OUTPUT LOW
V_CC
V_OL + 0.5V _VOL
Y/Z
1 (Note 12) 0/1 V_CC 100
FIGURE 5A. TEST CIRCUIT
FIGURE 5B. MEASUREMENT POINTS
FIGURE 5. DRIVER ENABLE AND DISABLE TIMES
DE
V_CC
DI
SIGNAL
GENERATOR
Z
D
Y
54Ω
C_D
+
V_OD
-
DI
DIFF OUT (Y - Z)
-V_OD
3V
0V
+V_OD
0V
FIGURE 6A. TEST CIRCUIT
FIGURE 6B. MEASUREMENT POINTS
FIGURE 6. DRIVER DATA RATE
10
FN7784.0
January 21, 2011