Datasheet

MAX3157
High CMRR RS-485 Transceiver
with ±50V Isolation
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
All voltages referenced to GND unless otherwise noted.
ELECTRICAL CHARACTERISTICS
(V
CC
= +5V ±5%, YR = ZR = AR = BR = ISOCOM, C1 = C2 = 0.047µF, C3 = C4 = 1µF, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at V
CC
= +5V and T
A
= +25°C.) (Note 1)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Supply Voltage (V
CC
).............................................................+7V
Cable Ground (ISOCOM) ....................................................±75V
Isolated Supply ISOVCC Relative to Cable Ground
(ISOCOM) ............................................................................+7V
Digital Input, Output Voltage
(DI, DE, RE, TXP, RXP, RO)......................-0.3V to (V
CC
+ 0.3V)
Digital Inputs (H/F) Relative to Cable Ground
(ISOCOM) ..........................................-0.3V to (ISOVCC + 0.3V)
Driver Output Voltage (Y, Z), Relative to Cable Ground
(ISOCOM).............................................................-8V to +12.5V
Receiver Input Voltage (A, B), Relative to Cable Ground
(ISOCOM).............................................................-8V to +12.5V
Termination Connections (YR, ZR, AR, BR) Relative to Cable
Ground (ISOCOM)................................................-8V to +12.5V
Charge-Pump Capacitance Low
(C1LO, C2LO) .......................................-0.3V to (V
CC
+ 0.3V)
Charge-Pump Capacitance High (C1HI, C2HI) Relative
to Cable Ground (ISOCOM) ...........-0.3V to (ISOVCC + 0.3V)
Continuous Power Dissipation
28-Pin SSOP (derate 10.8mW/°C above +70°C) ........860mW
28-Pin PDIP (derate 14.3mW/°C above +70°C)........1143mW
Operating Temperature Ranges
MAX3157C_I .....................................................0°C to +70°C
MAX3157E_I ..................................................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range ............................-65°C to +160°C
Lead Temperature (soldering, 10s) ................................+300°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DRIVER
Differential Driver Output,
No Load
V
OD1
Figure 1, R = 10MΩ 6V
Figure 1, R = 50Ω (RS-422) 2.0
Differential Driver Output,
Loaded
V
OD2
Figure 1, R = 27Ω (RS-485) 1.5
V
Change in Magnitude of
Differential Output Voltage
(Note 2)
∆V
OD
Figure 1, R = 50Ω or R = 27Ω 0.2 V
Driver Common-Mode Voltage V
OC
Figure 1, R = 50Ω or R = 27Ω,
V
OC
relative to ISOCOM
3.5 V
Change in Magnitude of
Common-Mode Voltage
(Note 2)
∆V
OC
Figure 1, R = 50Ω or R = 27Ω 0.2 V
Input High Voltage V
IH
DE, DI, RE, TXP, RXP, relative to GND,
H/F relative to ISOCOM
2.0 V
Input Low Voltage V
IL
DE, DI, RE, TXP, RXP, relative to GND,
H/F relative to ISOCOM
0.8 V
DI Input Hysteresis V
HYS
100 mV
I
IN1
DE, DI, RE ±2
Input Current
I
IN2
H/F, TXP, RXP internal pulldown 10 40
µA
DE = GND, V
CC
= GND or 5.25V, -7V ≤ (V
IN
-
V
ISOCOM
) ≤ 12V, AR = BR = ISOCOM
-5.0 8.0
Input Current (A and B) I
IN3
DE = GND, V
CC
= GND or 5.25V, -7V ≤ (V
IN
-
V
ISOCOM
) ≤ 12V, AR open, BR open
-0.58 1.0
mA