ISL4489E Datasheet, PDF (9/12 Pages) Intersil Corporation – Low Power, High Speed and Slew Rate Limited, Full Duplex, RS-485/RS-422 Transceivers

ISL4489E, ISL4491E
ESD Protection
All pins on these devices include class 3 Human Body
Model (HBM) ESD protection structures, but the RS-485
pins (driver outputs and receiver inputs) incorporate
advanced structures allowing them to survive ESD events
in excess of ±15kV HBM. The RS-485 pins are particularly
vulnerable to ESD damage because they typically connect
to an exposed port on the exterior of the finished product.
Simply touching the port pins, or connecting a cable, can
cause an ESD event that might destroy unprotected ICs.
These new ESD structures protect the device whether or
not it is powered up, protect without allowing any latchup
mechanism to activate, and without degrading the RS-485
common mode range of -7V to +12V. This built-in ESD
protection eliminates the need for board level protection
structures (e.g., transient suppression diodes), and the
associated, undesirable capacitive load they present.
Typical Performance Curves V_CC = 5V, T_A = 25°C; Unless Otherwise Specified
90
3.6
80
3.4
70
3.2
R_DIFF = 100Ω
60
3
50
2.8
40
2.6
30
20
2.4
R_DIFF = 54Ω
10
2.2
0
0
1
2
3
4
5
DIFFERENTIAL OUTPUT VOLTAGE (V)
FIGURE 6. DRIVER OUTPUT CURRENT vs DIFFERENTIAL
OUTPUT VOLTAGE
2
-40 -25
0
25
50
TEMPERATURE (°C)
75 85
FIGURE 7. DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs
TEMPERATURE
160
140
120
100
80
60
40
20
0
-20
-40
-60
-80 _ISL4489E
-100
-120
-7 -6 -4
Y OR Z = LOW
ISL4491E
ISL4489E
ISL4491E
Y OR Z = HIGH
-2 0
2
4
6
OUTPUT VOLTAGE (V)
8 10 12
FIGURE 8. DRIVER OUTPUT CURRENT vs SHORT CIRCUIT
VOLTAGE
400
350
ISL4491E, DE = X, RE = X
300
250
200
150
ISL4489E, DE = X, RE = X
100
50
-40 -25
0
25
50
TEMPERATURE (°C)
75 85
FIGURE 9. SUPPLY CURRENT vs TEMPERATURE
9
FN6074.2