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ISL32490E Datasheet, PDF (10/21 Pages) Intersil Corporation – ±60V Fault Protected, 5V, RS-485/RS-422 Transceivers with ±25V CMR
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
375Ω
VCM
375Ω
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
375Ω*
CD
RD
375Ω*
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
110Ω
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