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19-2668; Rev 2; 4/09
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
General Description
The MAX3070E–MAX3079E 3.3V, ±15kV ESD-protected,
RS-485/RS-422 transceivers feature one driver and one
receiver. These devices include fail-safe circuitry, guar-
anteeing a logic-high receiver output when receiver
inputs are open or shorted. The receiver outputs a logic
high if all transmitters on a terminated bus are disabled
(high impedance). The MAX3070E–MAX3079E include a
hot-swap capability to eliminate false transitions on the
bus during power-up or hot insertion.
The MAX3070E/MAX3071E/MAX3072E feature reduced
slew-rate drivers that minimize EMI and reduce reflec-
tions caused by improperly terminated cables, allowing
error-free data transmission up to 250kbps. The
MAX3073E/MAX3074E/MAX3075E also feature slew-
rate-limited drivers but allow transmit speeds up to
500kbps. The MAX3076E/MAX3077E/MAX3078E driver
slew rates are not limited, making transmit speeds up to
16Mbps possible. The MAX3079E slew rate is pin
selectable for 250kbps, 500kbps, and 16Mbps.
The MAX3072E/MAX3075E/MAX3078E are intended for
half-duplex communications, and the MAX3070E/
MAX3071E/MAX3073E/MAX3074E/MAX3076E/MAX307
7E are intended for full-duplex communications. The
MAX3079E is selectable for half-duplex or full-duplex
operation. It also features independently programmable
receiver and transmitter output phase through
separate pins.
The MAX3070E–MAX3079E transceivers draw 800µA
of supply current when unloaded or when fully loaded
with the drivers disabled. All devices have a 1/8-unit
load receiver input impedance, allowing up to 256
transceivers on the bus.
♦
3.3V Operation
♦
Electrostatic Discharge (ESD) Protection for
RS-485 I/O Pins
±15kV Human Body Model
♦
True Fail-Safe Receiver While Maintaining
EIA/TIA-485 Compatibility
♦
Hot-Swap Input Structure on DE and
RE
♦
Enhanced Slew-Rate Limiting Facilitates Error-
Free Data Transmission
(MAX3070E–MAX3075E/MAX3079E)
♦
Low-Current Shutdown Mode (Except
MAX3071E/MAX3074E/MAX3077E)
♦
Pin-Selectable Full-/Half-Duplex Operation
(MAX3079E)
♦
Phase Controls to Correct for Twisted-Pair
Reversal (MAX3079E)
♦
Allow Up to 256 Transceivers on the Bus
♦
Available in Industry-Standard 8-Pin SO Package
Features
MAX3070E–MAX3079E
Ordering Information
PART†
MAX3070EEPD
MAX3070EESD
MAX3070EAPD
MAX3070EASD
MAX3071EEPA
MAX3071EESA
MAX3071EAPA
MAX3071EASA
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +125°C
-40°C to +125°C
-40°C to +85°C
-40°C to +85°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
14 Plastic DIP
14 SO
14 Plastic DIP
14 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
Applications
Lighting Systems
Industrial Control
Telecom
Security Systems
Instrumentation
†Devices are available in both leaded (Pb) and lead(Pb)-free
packaging. Specify lead-free by adding a “+” after the part
number.
Ordering Information continued at end of data sheet.
Selector Guide, Pin Configurations, and Typical Operating
Circuits appear at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
MAX3070E–MAX3079E
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND)
Supply Voltage (V
CC
).............................................................+6V
Control Input Voltage (RE, DE, SLR,
H/F, TXP, RXP)......................................................-0.3V to +6V
Driver Input Voltage (DI)...........................................-0.3V to +6V
Driver Output Voltage (Z, Y, A, B) .............................-8V to +13V
Receiver Input Voltage (A, B)....................................-8V to +13V
Receiver Input Voltage
Full Duplex (A, B) ..................................................-8V to +13V
Receiver Output Voltage (RO)....................-0.3V to (V
CC
+ 0.3V)
Driver Output Current .....................................................±250mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SO (derate 5.88mW/°C above +70°C) .................471mW
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) .....727mW
14-Pin SO (derate 8.33mW/°C above +70°C) ...............667mW
14-Pin Plastic DIP (derate 10.0mW/°C above +70°C) ...800mW
Operating Temperature Ranges
MAX307_EE_ _ ................................................-40°C to +85°C
MAX307_EA_ _ ..............................................-40°C to +125°C
MAX3077EMSA .............................................-55°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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.
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 3.3V ±10%, T
A
=T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= 3.3V and T
A
= +25°C.) (Note 1)
PARAMETER
DRIVER
R
L
= 100
Differential Driver Output
Change in Magnitude of
Differential Output Voltage
Driver Common-Mode Output
Voltage
Change in Magnitude of
Common-Mode Voltage
Input High Voltage
Input Low Voltage
Input Hysteresis
Input Current
Input Impedance First Transition
Input Current
SRL Input High Voltage
SRL Input Middle Voltage
SRL Input Low Voltage
SRL Input Current
Output Leakage (Y and Z)
Full Duplex
I
O
SRL = V
CC
SRL = GND
DE = GND,
V
CC
= GND or 3.6V
V
IN
= +12V
V
IN
= -7V
-100
-75
125
I
IN2
V
OD
R
L
= 54
No load
V
OD
V
OC
V
OC
V
IH
V
IL
V
HYS
I
IN1
R
L
= 100
R
L
= 100
R
L
= 100
or 54 , Figure 1 (Note 2)
or 54 , Figure 1
or 54 , Figure 1 (Note 2)
2
0.8
100
±1
1
10
V
CC
- 0.4
V
CC
x 0.4
V
CC
x 0.6
0.4
75
10
40
V
CC
/ 2
(RS422), Figure 1
(RS485), Figure 1
2
1.5
V
CC
V
CC
V
CC
0.2
3
0.2
V
V
V
V
V
mV
μA
k
μA
V
V
V
μA
μA
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DE, DI,
RE,
TXP, RXP, H/F
DE, DI,
RE,
TXP, RXP, H/F
DE, DI,
RE,
TXP, RXP, H/F
DE, DI,
RE
DE
TXP, RXP, H/F internal pulldown
2
_______________________________________________________________________________________
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 3.3V ±10%, T
A
=T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= 3.3V and T
A
= +25°C.) (Note 1)
PARAMETER
Driver Short-Circuit Output
Current
Driver Short-Circuit Foldback
Output Current
Thermal-Shutdown Threshold
Thermal-Shutdown Hysteresis
Input Current (A and B)
RECEIVER
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
RO Output High Voltage
RO Output Low Voltage
Three-State Output Current at
Receiver
Receiver Input Resistance
Receiver Output Short-Circuit
Current
SUPPLY CURRENT
Supply Current
Supply Current in Shutdown
Mode
ESD PROTECTION
ESD Protection for Y, Z, A, and B
Human Body Model
±15
kV
I
CC
No load,
RE
= 0, DE = V
CC
No load,
RE
= V
CC
, DE = V
CC
No load,
RE
= 0, DE = 0
I
SHDN
RE
= V
CC
, DE = GND
0.8
0.8
0.8
0.05
1.5
1.5
1.5
10
μA
mA
V
TH
V
TH
V
OH
V
OL
I
OZR
R
IN
I
OSR
-7V
V
CM
12V
-200
-125
15
V
CC
- 0.6
0.4
±
1
96
±80
-50
mV
mV
V
V
μA
k
mA
SYMBOL
I
OSD
I
OSDF
T
TS
T
TSH
I
A, B
DE = GND,
V
CC
= GND or 3.6V
V
IN
= +12V
V
IN
= -7V
-100
0
-7V
-7V
V
OUT
V
OUT
V
OUT
CONDITIONS
12V (Note 3)
V
CC
(Note 3)
V
OUT
12V (Note 3)
1V (Note 3)
175
15
125
MIN
40
-250
20
-20
TYP
MAX
250
-40
UNITS
mA
mA
°C
°C
μA
MAX3070E–MAX3079E
(V
CC
- 1V)
V
A
+ V
B
= 0V
I
O
= -1mA
I
O
= 1mA
0
-7V
0V
V
O
V
CC
12V
V
CC
V
CM
V
RO
Note 1:
All currents into the device are positive. All currents out of the device are negative. All voltages are referred to device
ground, unless otherwise noted.
Note 2:
ΔV
OD
and
ΔV
OC
are the changes in V
OD
and V
OC
, respectively, when the DI input changes state.
Note 3:
The short-circuit output current applies to peak current just prior to foldback current limiting. The short-circuit foldback out-
put current applies during current limiting to allow a recovery from bus contention.
_______________________________________________________________________________________
3
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
MAX3070E–MAX3079E
DRIVER SWITCHING CHARACTERISTICS
MAX3070E/MAX3071E/MAX3072E/MAX3079E with SRL = UNCONNECTED (250kbps)
(V
CC
= 3.3V ±10%, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= 3.3V and T
A
= +25°C.)
PARAMETER
Driver Propagation Delay
Driver Differential Output Rise or
Fall Time
Differential Driver Output Skew
|t
DPLH
- t
DPHL
|
Maximum Data Rate
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Time to Shutdown
t
DZH
t
DZL
t
DLZ
t
DHZ
Figure 4
Figure 5
Figure 5
Figure 4
SYMBOL
t
DPLH
t
DPHL
t
DR ,
t
DF
t
DSKEW
CONDITIONS
C
L
= 50pF, R
L
= 54Ω, Figures 2 and 3
C
L
= 50pF, R
L
= 54Ω, Figures 2 and 3
C
L
= 50pF, R
L
= 54Ω, Figures 2 and 3
250
2500
2500
100
100
5500
5500
50
200
600
MIN
250
250
350
TYP
MAX
1500
1500
1600
200
UNITS
ns
ns
ns
kbps
ns
ns
ns
ns
ns
ns
ns
t
DZH(SHDN)
Figure 4
t
DZL(SHDN)
Figure 5
t
SHDN
RECEIVER SWITCHING CHARACTERISTICS
MAX3070E/MAX3071E/MAX3072E/MAX3079E with SRL = UNCONNECTED (250kbps)
(V
CC
= 3.3V ±10%, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= 3.3V and T
A
= +25°C.)
PARAMETER
Receiver Propagation Delay
Receiver Output Skew
|t
RPLH
- t
RPHL
|
Maximum Data Rate
Receiver Enable to Output Low
Receiver Enable to Output High
Receiver Disable Time from Low
Receiver Disable Time from High
Receiver Enable from Shutdown
to Output High
Receiver Enable from Shutdown
to Output Low
Time to Shutdown
t
RZL
t
RZH
t
RLZ
t
RHZ
Figure 8
Figure 8
Figure 8
Figure 8
SYMBOL
t
RPLH
t
RPHL
t
RSKEW
CONDITIONS
C
L
= 15pF, Figures 6 and 7
C
L
= 15pF, Figures 6 and 7
250
50
50
50
50
4000
4000
50
200
600
MIN
TYP
MAX
200
200
30
UNITS
ns
ns
kbps
ns
ns
ns
ns
ns
ns
ns
t
RZH(SHDN)
Figure 8
t
RZL(SHDN)
Figure 8
t
SHDN
4
_______________________________________________________________________________________
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