MAX3157
High CMRR RS-485 Transceiver
with ±50V Isolation
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
All voltages referenced to GND unless otherwise noted.
ELECTRICAL CHARACTERISTICS
(VCC = +5V ±5%, YR = ZR = AR = BR = ISOCOM, C1 = C2 = 0.047F, C3 = C4 = 1F, TA = TMIN to TMAX, unless otherwise noted.
Typical values are at VCC = +5V and TA = +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 (VCC).............................................................+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 (VCC + 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 (VCC + 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
VOD1
Figure 1, R = 10M
6V
Figure 1, R = 50
(RS-422)
2.0
Differential Driver Output,
Loaded
VOD2
Figure 1, R = 27
(RS-485)
1.5
V
Change in Magnitude of
Differential Output Voltage
(Note 2)
VOD
Figure 1, R = 50
or R = 27
0.2
V
Driver Common-Mode Voltage
VOC
Figure 1, R = 50
or R = 27,
VOC relative to ISOCOM
3.5
V
Change in Magnitude of
Common-Mode Voltage
(Note 2)
VOC
Figure 1, R = 50
or R = 27
0.2
V
Input High Voltage
VIH
DE, DI, RE, TXP, RXP, relative to GND,
H/F relative to ISOCOM
2.0
V
Input Low Voltage
VIL
DE, DI, RE, TXP, RXP, relative to GND,
H/F relative to ISOCOM
0.8
V
DI Input Hysteresis
VHYS
100
mV
IIN1
DE, DI, RE
±2
Input Current
IIN2
H/F, TXP, RXP internal pulldown
10
40
A
DE = GND, VCC = GND or 5.25V, -7V
≤ (VIN -
VISOCOM)
≤ 12V, AR = BR = ISOCOM
-5.0
8.0
Input Current (A and B)
IIN3
DE = GND, VCC = GND or 5.25V, -7V
≤ (VIN -
VISOCOM)
≤ 12V, AR open, BR open
-0.58
1.0
mA