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ISL32490E Datasheet, PDF (10/21 Pages) Intersil Corporation – ±60V Fault Protected, 5V, RS-485/RS-422 Transceivers with ±25V CMR | |||
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ISL32490E, ISL32492E, ISL32493E, ISL32495E, ISL32496E, ISL32498E
Test Circuits and Waveforms
VCC DE
DI
Z
D
Y
VOD
RL/2
RL/2 VOC
VCC DE
DI
Z
D
Y
RL/2
VOD
VOC
RL/2
375â¦
VCM
375â¦
FIGURE 3A. VOD AND VOC
FIGURE 3B. VOD AND VOC WITH COMMON MODE LOAD
FIGURE 3. DC DRIVER TEST CIRCUITS
3V
DI
1.5V
1.5V
0V
DE
VCC
DI
SIGNAL
GENERATOR
Z
D
Y
375â¦*
CD
RD
375â¦*
VCM
*USED ONLY FOR COMMON
MODE LOAD TESTS
OUT (Z)
OUT (Y)
tPLH
90%
DIFF OUT (Y - Z)
10%
tR
tPHL
VOH
VOL
90%
10%
tF
+VOD
-VOD
SKEW = |tPLH - tPHL|
FIGURE 4A. TEST CIRCUIT
FIGURE 4B. MEASUREMENT POINTS
FIGURE 4. DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES
SIGNAL
GENERATOR
PARAMETER
tHZ
tLZ
tZH
tZL
tZH(SHDN)
tZL(SHDN)
DE
DI
Z
D
Y
110â¦
VCC
SW GND
CL
OUTPUT
RE
DI SW CL (pF)
Y/Z
X
1/0 GND 50
Y/Z
X
0/1 VCC
50
Y/Z
0 (Note 9) 1/0 GND 100
Y/Z
0 (Note 9) 0/1 VCC 100
Y/Z
1 (Note 12) 1/0 GND 100
DE
(Note 11)
tZH, tZH(SHDN)
(Note 11)
OUT (Y, Z)
tZL, tZL(SHDN)
(Note 11)
OUT (Y, Z)
1.5V
3V
1.5V
0V
tHZ
OUTPUT HIGH
2.3V
VOH - 0.5V VOH
0V
tLZ
2.3V
OUTPUT LOW
VCC
VOL + 0.5V VOL
Y/Z
1 (Note 12) 0/1 VCC 100
FIGURE 5A. TEST CIRCUIT
FIGURE 5B. MEASUREMENT POINTS
FIGURE 5. DRIVER ENABLE AND DISABLE TIMES
10
FN7786.0
January 18, 2011
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