ISL32492EIBZ-T Intersil, ISL32492EIBZ-T Datasheet - Page 11

• Manufacturer Part Number: ISL32492EIBZ-T
• Description: IC TXRX RS485 FAULT PROT 8SOIC
• Manufacturer: Intersil
• Type: Transceiverr

Specifications of ISL32492EIBZ-T

• Number Of Drivers/receivers: 1/1
• Protocol: RS422, RS485
• Voltage - Supply: 4.5 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Test Circuits and Waveforms
Application Information
RS-485 and RS-422 are differential (balanced) data
transmission standards used for long haul or noisy environments.
RS-422 is a subset of RS-485, so RS-485 transceivers are also
RS-422 compliant. RS-422 is a point-to-multipoint (multidrop)
standard, which allows only one driver and up to 10 (assuming
one-unit load devices) receivers on each bus. RS-485 is a true
multipoint standard, which allows up to 32 one-unit load devices
(any combination of drivers and receivers) on each bus. To allow
for multipoint operation, the RS-485 specification requires that
SIGNAL
GENERATOR
SIGNAL
GENERATOR
t
ISL32490E, ISL32492E, ISL32493E, ISL32495E, ISL32496E, ISL32498E
t
ZH
ZL
(SHDN) (Note 13)
(SHDN) (Note 13)
t
t
PARAMETER
ZH
ZL
SIGNAL
GENERATOR
V
(Note 10)
(Note 10)
CC
t
t
HZ
LZ
V
DE
DI
CM
FIGURE 6A. TEST CIRCUIT
FIGURE 7A. TEST CIRCUIT
FIGURE 8A. TEST CIRCUIT
RE
D
B
A
Y
Z
11
B
A
DE
R
0
0
0
0
0
0
RE
SIGNAL
GENERATOR
RO
54Ω
R
FIGURE 7. RECEIVER PROPAGATION DELAY AND DATA RATE
+1.5V
+1.5V
+1.5V
RO
-1.5V
-1.5V
-1.5V
FIGURE 8. RECEIVER ENABLE AND DISABLE TIMES
A
15pF
C
1kΩ
D
15pF
FIGURE 6. DRIVER DATA RATE
SW
GND
GND
GND
(Continued)
SW
V
V
V
CC
CC
CC
V
GND
V
OD
+
-
CC
drivers must handle bus contention without sustaining any
damage.
Another important advantage of RS-485 is the extended
common mode range (CMR), which specifies that the driver
outputs and receiver inputs withstand signals that range from
+12V to -7V. RS-422 and RS-485 are intended for runs as long as
4000 feet; thus, the wide CMR is necessary to handle ground
potential differences, as well as voltages induced in the cable by
external fields.
The ISL3249xE is a family of ruggedized RS-485 transceivers
that improves on the RS-485 basic requirements and thereby
t
(Note 11)
(Note 11)
RO
ZH
B
A
t
ZL
DIFF OUT (Y - Z)
, t
RE
RO
RO
, t
ZH(SHDN)
ZL(SHDN)
DI
(Note 11)
FIGURE 6B. MEASUREMENT POINTS
FIGURE 7B. MEASUREMENT POINTS
FIGURE 8B. MEASUREMENT POINTS
t
PLH
V
CM
-V
1.5V
OD
50%
OUTPUT HIGH
1.5V
1.5V
OUTPUT LOW
t
PHL
V
t
t
CM
HZ
LZ
1.5V
50%
V
V
OH
OL
+V
V
V
- 0.5V
+ 0.5V
CM
CM
January 18, 2011
OD
3V
0V
+ 750mV
- 750mV
V
0V
CC
3V
0V
0V
FN7786.0
V
V
V
0V
OH
CC
OL