ISL32483E Datasheet, PDF (8/17 Pages) Intersil Corporation – Fault Protected, Extended CMR, RS-485/RS-422 Transceivers

ISL32483E, ISL32485E
Test Circuits and Waveforms
V_CC ^DE
DI
Z
D
Y
V_OD
R_L/2
R_L/2 VOC
V_CC ^DE
DI
Z
D
Y
R_L/2
V_OD
V_OC
R_L/2
375Ω
V_CM
375Ω
FIGURE 3A. V_OD AND V_OC
FIGURE 3B. V_OD AND V_OC WITH COMMON MODE LOAD
FIGURE 3. DC DRIVER TEST CIRCUITS
3V
DI
50%
50%
0V
DE
V_CC
DI
SIGNAL
GENERATOR
Z
D
Y
375Ω*
C_D
R_D
375Ω*
V_CM
*ONLY USED FOR COMMON
MODE LOAD TESTS
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
SKEW = |t_PLH - t_PHL|
FIGURE 4A. TEST CIRCUIT
FIGURE 4B. MEASUREMENT POINTS
FIGURE 4. DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES
SIGNAL
GENERATOR
DE
DI
Z
D
Y
110Ω
C_L
V_CC
SW ^GND
PARAMETER
t_HZ
t_LZ
t_ZH
t_ZL
t_ZH(SHDN)
t_ZL(SHDN)
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
Y/Z
1 (Note 12) 0/1 V_CC 100
DE
(Note 11)
t_ZH, t_ZH(SHDN)
(Note 11)
OUT (Y, Z)
t_ZL, t_ZL(SHDN)
(Note 11)
OUT (Y, Z)
50%
3V
50%
0V
t_HZ
OUTPUT HIGH
2.3V
V_OH - 0.5V
V_OH
0V
t_LZ
2.3V
OUTPUT LOW
V_CC
V_OL + 0.5V _VOL
FIGURE 5A. TEST CIRCUIT
FIGURE 5B. MEASUREMENT POINTS
FIGURE 5. DRIVER ENABLE AND DISABLE TIMES
8
FN7785.0
January 18, 2011