AVAILABLE
Functional Diagrams
Pin Configurations appear at end of data sheet.
Functional Diagrams continued at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
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.
Applications
Lighting Systems
Industrial Control
Telecom
Security Systems
Instrumentation
Features
♦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
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
Ordering Information
19-2668; Rev 2; 4/09
PART† TEMP RANGE PIN-PACKAGE
MAX3070EEPD -40°C to +85°C 14 Plastic DIP
MAX3070EESD -40°C to +85°C 14 SO
MAX3070EAPD -40°C to +125°C 14 Plastic DIP
MAX3070EASD -40°C to +125°C 14 SO
MAX3071EEPA -40°C to +85°C 8 Plastic DIP
MAX3071EESA -40°C to +85°C 8 SO
MAX3071EAPA -40°C to +125°C 8 Plastic DIP
MAX3071EASA -40°C to +125°C 8 SO
Selector Guide, Pin Configurations, and Typical Operating
Circuits appear at end of data sheet.
Ordering Information continued at end of data sheet.
†Devices are available in both leaded (Pb) and lead(Pb)-free
packaging. Specify lead-free by adding a “+” after the part
number.
MAX3070E–MAX3079E
Ordering Information
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(VCC = 3.3V ±10%, TA=TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.3V 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.
(All voltages referenced to GND)
Supply Voltage (VCC).............................................................+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 (VCC + 0.3V)
Driver Output Current .....................................................±250mA
Continuous Power Dissipation (TA= +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
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DRIVER
RL = 100 (RS422), Figure 1 2 VCC
RL = 54 (RS485), Figure 1 1.5 VCC
Differential Driver Output VOD
No load VCC
V
Change in Magnitude of
Differential Output Voltage VOD RL = 100 or 54, Figure 1 (Note 2) 0.2 V
Driver Common-Mode Output
Voltage VOC R
L = 100 or 54, Figure 1 VCC / 2 3 V
Change in Magnitude of
Common-Mode Voltage VOC RL = 100 or 54, Figure 1 (Note 2) 0.2 V
Input High Voltage VIH DE, DI, RE, TXP, RXP, H/F 2 V
Input Low Voltage VIL DE, DI, RE, TXP, RXP, H/F 0.8 V
Input Hysteresis VHYS DE, DI, RE, TXP, RXP, H/F 100 mV
Input Current IIN1 DE, DI, RE ±1 μA
Input Impedance First Transition DE 1 10 k
Input Current IIN2 TXP, RXP, H/F internal pulldown 10 40 μA
SRL Input High Voltage VCC - 0.4 V
SRL Input Middle Voltage VCC x 0.4 VCC x 0.6 V
SRL Input Low Voltage 0.4 V
SRL = VCC 75
SRL Input Current SRL = GND -75 μA
VIN = +12V 125
Output Leakage (Y and Z)
Full Duplex IODE = GND,
VCC = GND or 3.6V VIN = -7V -100 μA
MAX3070E–MAX3079E
2
Maxim Integrated
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(VCC = 3.3V ±10%, TA=TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.3V and TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
0 VOUT 12V (Note 3) 40 250
Driver Short-Circuit Output
Current IOSD -7V VOUT VCC (Note 3) -250 -40 mA
(VCC - 1V) VOUT 12V (Note 3) 20
Driver Short-Circuit Foldback
Output Current IOSDF -7V VOUT 1V (Note 3) -20 mA
Thermal-Shutdown Threshold TTS 175 °C
Thermal-Shutdown Hysteresis TTSH 15 °C
VIN = +12V 125
Input Current (A and B) IA, B DE = GND,
VCC = GND or 3.6V VIN = -7V -100 μA
RECEIVER
Receiver Differential Threshold
Voltage VTH -7V VCM 12V -200 -125 -50 mV
Receiver Input Hysteresis VTH V
A + VB = 0V 15 mV
RO Output High Voltage VOH IO = -1mA VCC - 0.6 V
RO Output Low Voltage VOL IO = 1mA 0.4 V
Three-State Output Current at
Receiver IOZR 0 VO VCC ± 1 μA
Receiver Input Resistance RIN -7V VCM 12V 96 k
Receiver Output Short-Circuit
Current IOSR 0V VRO VCC ±80 mA
SUPPLY CURRENT
No load, RE = 0, DE = VCC 0.8 1.5
No load, RE = VCC, DE = VCC 0.8 1.5
Supply Current ICC
No load, RE = 0, DE = 0 0.8 1.5
mA
Supply Current in Shutdown
Mode ISHDN RE = VCC, DE = GND 0.05 10 μA
ESD PROTECTION
ESD Protection for Y, Z, A, and B Human Body Model ±15 kV
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: ΔVOD and ΔVOC are the changes in VOD and VOC, 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.
MAX3070E–MAX3079E
Maxim Integrated
3
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
DRIVER SWITCHING CHARACTERISTICS
MAX3070E/MAX3071E/MAX3072E/MAX3079E with SRL = UNCONNECTED (250kbps)
(VCC = 3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
tDPLH 250 1500
Driver Propagation Delay tDPHL
CL= 50pF, RL= 54Ω, Figures 2 and 3 250 1500 ns
Driver Differential Output Rise or
Fall Time tDR
tDF CL= 50pF, RL= 54Ω, Figures 2 and 3 350 1600 ns
Differential Driver Output Skew
|tDPLH - tDPHL|tDSKEW CL= 50pF, RL= 54Ω, Figures 2 and 3 200 ns
Maximum Data Rate 250 kbps
Driver Enable to Output High tDZH Figure 4 2500 ns
Driver Enable to Output Low tDZL Figure 5 2500 ns
Driver Disable Time from Low tDLZ Figure 5 100 ns
Driver Disable Time from High tDHZ Figure 4 100 ns
Driver Enable from Shutdown to
Output High tDZH
SHDN
Figure 4 5500 ns
Driver Enable from Shutdown to
Output Low tDZL
SHDN
Figure 5 5500 ns
Time to Shutdown tSHDN 50 200 600 ns
RECEIVER SWITCHING CHARACTERISTICS
MAX3070E/MAX3071E/MAX3072E/MAX3079E with SRL = UNCONNECTED (250kbps)
(VCC = 3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
tRPLH 200
Receiver Propagation Delay tRPHL
CL = 15pF, Figures 6 and 7 200 ns
Receiver Output Skew
|tRPLH - tRPHL|tRSKEW CL = 15pF, Figures 6 and 7 30 ns
Maximum Data Rate 250 kbps
Receiver Enable to Output Low tRZL Figure 8 50 ns
Receiver Enable to Output High tRZH Figure 8 50 ns
Receiver Disable Time from Low tRLZ Figure 8 50 ns
Receiver Disable Time from High tRHZ Figure 8 50 ns
Receiver Enable from Shutdown
to Output High tRZH
SHDN
Figure 8 4000 ns
Receiver Enable from Shutdown
to Output Low tRZL
SHDN
Figure 8 4000 ns
Time to Shutdown tSHDN 50 200 600 ns
MAX3070E–MAX3079E
4
Maxim Integrated
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
DRIVER SWITCHING CHARACTERISTICS
MAX3073E/MAX3074E/MAX3075E/MAX3079E with SRL = VCC (500kbps)
(VCC = 3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
tDPLH 180 800
Driver Propagation Delay tDPHL
CL = 50pF, RL = 54Ω, Figures 2 and 3 180 800 ns
Driver Differential Output Rise or
Fall Time tDR
tDF CL = 50pF, RL = 54Ω, Figures 2 and 3 200 800 ns
Differential Driver Output Skew
|tDPLH - tDPHL|tDSKEW CL = 50pF, RL = 54Ω, Figures 2 and 3 100 ns
Maximum Data Rate 500 kbps
Driver Enable to Output High tDZH Figure 4 2500 ns
Driver Enable to Output Low tDZL Figure 5 2500 ns
Driver Disable Time from Low tDLZ Figure 5 100 ns
Driver Disable Time from High tDHZ Figure 4 100 ns
Driver Enable from Shutdown to
Output High tDZH
SHDN
Figure 4 4500 ns
Driver Enable from Shutdown to
Output Low tDZL
SHDN
Figure 5 4500 ns
Time to Shutdown tSHDN 50 200 600 ns
RECEIVER SWITCHING CHARACTERISTICS
MAX3073E/MAX3074E/MAX3075E/MAX3079E with SRL = VCC (500kbps)
(VCC = 3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
tRPLH 200
Receiver Propagation Delay tRPHL
CL = 15pF, Figures 6 and 7 200 ns
Receiver Output Skew
|tRPLH - tRPHL|tRSKEW CL = 15pF, Figures 6 and 7 30 ns
Maximum Data Rate 500 kbps
Receiver Enable to Output Low tRZL Figure 8 50 ns
Receiver Enable to Output High tRZH Figure 8 50 ns
Receiver Disable Time from Low tRLZ Figure 8 50 ns
Receiver Disable Time from High tRHZ Figure 8 50 ns
Receiver Enable from Shutdown
to Output High tRZH
(
SHDN
)
Figure 8 4000 ns
Receiver Enable from Shutdown
to Output Low tRZL
(
SHDN
)
Figure 8 4000 ns
Time to Shutdown tSHDN 50 200 600 ns
MAX3070E–MAX3079E
Maxim Integrated
5
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
DRIVER SWITCHING CHARACTERISTICS
MAX3076E/MAX3077E/MAX3078E/MAX3079E with SRL = GND (16Mbps)
(VCC = 3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
tDPLH 50
Driver Propagation Delay tDPHL
CL = 50pF, RL= 54Ω, Figures 2 and 3 50 ns
Driver Differential Output Rise or
Fall Time tDR
tDF CL = 50pF, RL= 54Ω, Figures 2 and 3 15 ns
Differential Driver Output Skew
|tDPLH - tDPHL|tDSKEW CL = 50pF, RL= 54Ω, Figures 2 and 3 8 ns
Maximum Data Rate 16 Mbps
Driver Enable to Output High tDZH Figure 4 150 ns
Driver Enable to Output Low tDZL Figure 5 150 ns
Driver Disable Time from Low tDLZ Figure 5 100 ns
Driver Disable Time from High tDHZ Figure 4 100 ns
Driver Enable from Shutdown to
Output High tDZH
SHDN
Figure 4 1250 1800 ns
Driver Enable from Shutdown to
Output Low tDZL
SHDN
Figure 5 1250 1800 ns
Time to Shutdown tSHDN 50 200 600 ns
RECEIVER SWITCHING CHARACTERISTICS
MAX3076E/MAX3077E/MAX3078E/MAX3079E with SRL = GND (16Mbps)
(VCC = 3.3V ±10%, TA= TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.3V and TA= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
tRPLH 40 75
Receiver Propagation Delay tRPHL
CL = 15pF, Figures 6 and 7 40 75 ns
Receiver Output Skew
|tRPLH - tRPHL|tRSKEW CL = 15pF, Figures 6 and 7 8 ns
Maximum Data Rate 16 Mbps
Receiver Enable to Output Low tRZL Figure 8 50 ns
Receiver Enable to Output High tRZH Figure 8 50 ns
Receiver Disable Time from Low tRLZ Figure 8 50 ns
Receiver Disable Time from High tRHZ Figure 8 50 ns
Receiver Enable from Shutdown
to Output High tRZH
(
SHDN
)
Figure 8 1800 ns
Receiver Enable from Shutdown
to Output Low tRZL
(
SHDN
)
Figure 8 1800 ns
Time to Shutdown tSHDN 50 200 600 ns
MAX3070E–MAX3079E
6
Maxim Integrated
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
SUPPLY CURRENT vs. TEMPERATURE
MAX3070E toc01
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
1007550250-25
0.6
0.7
0.8
0.9
1.0
0.5
-50 125
DE = VCC
DE = 0
OUTPUT CURRENT
vs. RECEIVER OUTPUT HIGH VOLTAGE
MAX3070E toc02
OUTPUT HIGH VOLTAGE (V)
OUTPUT CURRENT (mA)
3.02.52.01.51.00.5
5
10
15
20
25
30
0
0 3.5
OUTPUT CURRENT
vs. RECEIVER OUTPUT LOW VOLTAGE
MAX3070E toc03
OUTPUT HIGH VOLTAGE (V)
OUTPUT CURRENT (mA)
3.02.52.01.51.00.5
5
10
15
20
25
30
35
0
0 3.5
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
MAX3070E toc04
TEMPERATURE (°C)
OUTPUT HIGH VOLTAGE (V)
1007550250-25
3.05
3.10
3.15
3.20
3.25
3.30
3.00
-50 125
IO = -1mA
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
MAX3070E toc05
TEMPERATURE (°C)
OUTPUT LOW VOLTAGE (V)
10075-25 0 25 50
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0
-50 125
IO = -1mA
DRIVER OUTPUT CURRENT
vs. DIFFERENTIAL OUTPUT VOLTAGE
MAX3070E toc06
DIFFERENTIAL OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
3.02.51.5 2.01.00.5
10
20
30
40
50
60
70
80
90
100
0
0 3.5
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
XMAX3070E toc07
TEMPERATURE (°C)
DIFFERENTIAL OUTPUT VOLTAGE (V)
1007525 500-25
1.70
1.80
1.90
2.00
2.10
2.20
2.30
2.40
2.50
2.60
1.60
-50 125
RL = 54Ω
OUTPUT CURRENT
vs. TRANSMITTER OUTPUT HIGH VOLTAGE
MAX3070E toc08
OUTPUT HIGH VOLTAGE (V)
OUTPUT CURRENT (mA)
32-6 -5 -4 -2 -1 0-3 1
20
40
60
80
100
120
140
160
0
-7 4
OUTPUT CURRENT
vs. TRANSMITTER OUTPUT LOW VOLTAGE
MAX3070E toc09
OUTPUT LOW VOLTAGE (V)
OUTPUT CURRENT (mA)
108642
20
40
60
80
100
120
140
160
180
0
012
Typical Operating Characteristics
(VCC = 3.3V, TA = +25°C, unless otherwise noted. Note: The MAX3077EMSA/PR meets specification over temperature.)
MAX3070E–MAX3079E
Maxim Integrated
7
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
SHUTDOWN CURRENT
vs. TEMPERATURE
MAX3070E toc10
TEMPERATURE (°C)
SHUTDOWN CURRENT (μA)
1007525 500-25
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0
-50 125
DRIVER PROPAGATION DELAY
vs. TEMPERATURE (250kbps)
MAX3070E toc11
TEMPERATURE (°C)
DRIVER PROPAGATION DELAY (ns)
1007550250-25
600
700
800
900
1000
500
-50 125
tDPLH
tDPHL
DRIVER PROPAGATION DELAY
vs. TEMPERATURE (500kbps)
MAX3070E toc12
TEMPERATURE (°C)
DRIVER PROPAGATION DELAY (ns)
1007550250-25
250
300
350
400
450
500
200
-50 125
tDPLH
tDPHL
DRIVER PROPAGATION DELAY
vs. TEMPERATURE (16Mbps)
MAX3070E toc13
TEMPERATURE (°C)
DRIVER PROPAGATION DELAY (ns)
1007550250-25
5
10
15
20
25
30
0
-50 125
tDPLH
tDPHL
RECEIVER PROPAGATION DELAY
vs. TEMPERATURE (250kbps AND 500kbps)
MAX3070E toc14
TEMPERATURE (°C)
DRIVER PROPAGATION DELAY (ns)
1007550250-25
30
60
90
120
150
0
-50 125
tDPLH
tDPHL
RECEIVER PROPAGATION DELAY
vs. TEMPERATURE (16Mbps)
MAX3070E toc15
TEMPERATURE (°C)
RECEIVER PROPAGATION DELAY (ns)
1007550250-25
10
20
30
40
50
60
70
0
-50 125
tDPLH
tDPHL
DRIVER PROPAGATION DELAY (250kbps)
MAX3070E toc16
1μs/div
VY - VZ
2V/div
DI
2V/div
RECEIVER PROPAGATION DELAY
(250kbps AND 500kbps)
MAX3070E toc17
200ns/div
VA - VB
1V/div
RO
2V/div
Typical Operating Characteristics (continued)
(VCC = 3.3V, TA = +25°C, unless otherwise noted. Note: The MAX3077EMSA/PR meets specification over temperature.)
MAX3070E–MAX3079E
8
Maxim Integrated
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
Test Circuits and Waveforms
DRIVER PROPAGATION DELAY (500kbps)
MAX3070E toc18
400ns/div
VY - VZ
2V/div
DI
2V/div
DRIVER PROPAGATION DELAY (16Mbps)
MAX3070E toc19
10ns/div
VZ
1V/div
VY
1V/div
DI
2V/div
RECEIVER PROPAGATION DELAY (16Mbps)
MAX3070E toc20
20ns/div
VA
1V/div
VB
1V/div
RO
2V/div
Typical Operating Characteristics (continued)
(VCC = 3.3V, TA = +25°C, unless otherwise noted. Note: The MAX3077EMSA/PR meets specification over temperature.)
Y
Z
VOD
VOC
RL/2
RL/2
Figure 1. Driver DC Test Load
DI
DE
3V
Z
Y
VOD RLCL
Figure 2. Driver Timing Test Circuit
DI
VCC
0
Z
Y
VO
0
-VO
VO
VCC/2
tDPLH tDPHL
1/2 VO
10%
tDR
90% 90%
1/2 VO
10%
tDF
VDIFF = V (Y) - V (Z)
VDIFF
tSKEW = | tDPLH - tDPHL |
Figure 3. Driver Propagation Delays
MAX3070E–MAX3079E
Maxim Integrated
9
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
Test Circuits and Waveforms (continued)
DE
OUT
tDHZ
0
VCC
VCC / 2
0.25V
0
VOH
GENERATOR
0 OR 3V
S1
50Ω
DOUT
tDZH, tDZH(SHDN)
VOM = (0 + VOH) / 2
RL = 500Ω
CL
50pF
Figure 4. Driver Enable and Disable Times (tDHZ, tDZH, tDZH(SHDN))
DE
VCC
OUT
tDLZ
0
VCC
VCC / 2
GENERATOR
0 OR 3V
S1
50Ω
DOUT
tDZL, tDZL(SHDN)
VOM = (VOL + VCC) / 2
RL = 500Ω
CL
50pF
VOL 0.25V
VCC
Figure 5. Driver Enable and Disable Times (tDZL, tDLZ, tDLZ(SHDN))
MAX3070E–MAX3079E
10
Maxim Integrated
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
Test Circuits and Waveforms (continued)
VID R
B
A
RECEIVER
OUTPUT
ATE
Figure 6. Receiver Propagation Delay Test Circuit
A
B
RO
VOH
1.5V
tRPLH
tRPHL
VOL
+1V
-1V
THE RISE TIME AND FALL TIME OF INPUTS A AND B < 4ns
Figure 7. Receiver Propagation Delays
S1 OPEN
S2 CLOSED
S3 = +1.5V
RO
3V
0
0
VOH
VOH / 2
S1 OPEN
S2 CLOSED
S3 = +1.5V
tRHZ
3V
0
0
VOH
0.25V
1.5V
S1 CLOSED
S2 OPEN
S3 = -1.5V
3V
0
VOL
VCC
1.5V
S1 CLOSED
S2 OPEN
S3 = -1.5V
tRLZ
3V
0
VOL
VCC
1.5V
0.25V
GENERATOR
VCC
+1.5V
1kΩ
CL
15pF S2
S1
50Ω
S3
-1.5V R
VID
RE
RO
RE
RO
RE
RO
RE
tRZH, tRZH(SHDN) tRZL, tRZL(SHDN)
(VOL + VCC) / 2
Figure 8. Receiver Enable and Disable Times
MAX3070E–MAX3079E
Maxim Integrated
11
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
Pin Description
PIN
MAX3070E
MAX3073E
MAX3076E
MAX3071E
MAX3074E
MAX3077E
MAX3072E
MAX3075E
MAX3078E
MAX3079E
FULL-DUPLEX
DEVICES
HALF-
DUPLEX
DEVICES
FULL-
DUPLE
X MODE
HALF-
DUPLE
X MODE
NAME FUNCTION
— — — 1 1 H/F
Half-/Full-Duplex Select Pin. Connect H/F to VCC for half-
duplex mode; connect to GND or leave unconnected for
full-duplex mode.
2 2 1 2 2 RO
Receiver Output. When RE is low and if (A - B) -50mV,
RO is high; if (A - B) -200mV, RO is low.
3 — 2 3 3 RE
Receiver Output Enable. Drive RE low to enable RO; RO
is high impedance when RE is high. Drive RE high and
DE low to enter low-power shutdown mode. RE is a hot-
swap input (see the Hot-Swap Capability section for
details).
4 — 3 4 4 DE
Driver Output Enable. Drive DE high to enable driver
outputs. These outputs are high impedance when DE is
low. Drive RE high and DE low to enter low-power
shutdown mode. DE is a hot-swap input (see the Hot-
Swap Capability section for details).
5 3 4 5 5 DI
Driver Input. With DE high, a low on DI forces noninverting
output low and inverting output high. Similarly, a high on
DI forces noninverting output high and inverting output
low.
— — — 6 6 SRL
Slew-Rate Limit Selector Pin. Connect SRL to ground for
16Mbps communication rate; connect to VCC for
500kbps communication rate. Leave unconnected for
250kbps communication rate.
6, 7 4 5 7 7 GND Ground
— — — 8 8 TXP
Transmitter Phase. Connect TXP to ground or leave
unconnected for normal transmitter phase/polarity.
Connect to VCC to invert the transmitter phase/polarity.
9 5 — 9 — Y Noninverting Driver Output
— — — — 9 Y
Noninverting Driver Output and Noninverting Receiver
Input*
10 6 — 10 — Z Inverting Driver Output
— — — — 10 Z Inverting Driver Output and Inverting Receiver Input*
11 7 — 11 — B Inverting Receiver Input
— — — — 11 B Receiver Input Resistors*
— — 7 — — B Inverting Receiver Input and Inverting Driver Output
MAX3070E–MAX3079E
12
Maxim Integrated
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
MAX3070E/MAX3073E/MAX3076E
Pin Description (continued)
PIN
MAX3070E
MAX3073E
MAX3076E
MAX3071E
MAX3074E
MAX3077E
MAX3072E
MAX3075E
MAX3078E
MAX3079E
FULL-DUPLEX
DEVICES
HALF-
DUPLEX
DEVICES
FULL-
DUPLE
X MODE
HALF-
DUPLE
X MODE
NAME FUNCTION
12 8 — 12 — A Noninverting Receiver Input
— — — — 12 A Receiver Input Resistors*
— — 6 — — A
Noninverting Receiver Input and Noninverting Driver
Output
— — — 13 13 RXP
Receiver Phase. Connect RXP to GND or leave
unconnected for normal transmitter phase/polarity.
Connect to VCC to invert receiver phase/polarity.
14 1 8 14 14 VCC Positive Supply VCC = 3.3V ±10%. Bypass VCC to GND
with a 0.1μF capacitor.
1, 8, 13 — — — — N.C. No Connect. Not internally connected. Can be
connected to GND.
*
MAX3079E only. In half-duplex mode, the driver outputs serve as receiver inputs. The full-duplex receiver inputs (A and B) still have a
1/8-unit load, but are not connected to the receiver.
TRANSMITTING
INPUTS OUTPUTS
RE DE DI Z Y
X1101
X1010
0 0 X High-Z High-Z
1 0 X Shutdown
RECEIVING
INPUTS OUTPUT
RE DE A, B RO
0X≥ -50mV 1
0X≤ -200mV 0
0X
Open/
shorted 1
1 1 X High-Z
1 0 X Shutdown
MAX3071E/MAX3074E/MAX3077E
TRANSMITTING
INPUT OUTPUTS
DI Z Y
101
010
RECEIVING
INPUTS OUTPUT
A, B RO
≥ -50mV 1
≤ -200mV 0
Open/shorted 1
Function Tables
MAX3070E–MAX3079E
Maxim Integrated
13
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
MAX3072E/MAX3075E/MAX3078E
TRANSMITTING
INPUTS OUTPUTS
RE DE DI B/Z A/Y
X1101
X1010
0 0 X High-Z High-Z
1 0 X Shutdown
Function Tables (continued)
MAX3079E
TRANSMITTING
INPUTS OUTPUTS
TXP RE DE DI Z Y
0X1101
0X1010
1X1110
1X1001
X 0 0 X High-Z High-Z
X 1 0 X Shutdown
RECEIVING
INPUTS OUTPUTS
H/FRXP RE DE A, B Y, Z RO
0 0 0 X > -50mV X 1
0 0 0 X < -200mV X 0
0 1 0 X > -50mV X 0
0 1 0 X < -200mV X 1
1000X> -50mV 1
1000X< -200mV 0
1100X> -50mV 0
1100X< -200mV 1
0 0 0 X Open/shorted X 1
1000XOpen/shorted 1
0 1 0 X Open/shorted X 0
1100XOpen/shorted 0
X X 1 1 X X High-Z
X X 1 0 X X Shutdown
RECEIVING
INPUTS OUTPUTS
RE DE A-B RO
0X≥ -50mV 1
0X≤ -200mV 0
0X
Open/
shorted 1
1 1 X High-Z
1 0 X Shutdown
X = Don’t care; shutdown mode, driver and receiver outputs are high impedance.
MAX3070E–MAX3079E
14
Maxim Integrated
Detailed Description
The MAX3070E–MAX3079E high-speed transceivers for
RS-485/RS-422 communication contain one driver and
one receiver. These devices feature fail-safe circuitry,
which guarantees a logic-high receiver output when the
receiver inputs are open or shorted, or when they are
connected to a terminated transmission line with all dri-
vers disabled (see the
Fail-Safe
section). The
MAX3070E/MAX3072E/MAX3073E/MAX3075E/
MAX3076E/MAX3078E/MAX3079E also feature a hot-
swap capability allowing line insertion without erro-
neous data transfer (see the
Hot Swap Capability
section). The MAX3070E/MAX3071E/MAX3072E feature
reduced slew-rate drivers that minimize EMI and
reduce reflections caused by improperly terminated
cables, allowing error-free data transmission up to
250kbps. The MAX3073E/MAX3074E/MAX3075E also
offer slew-rate limits allowing transmit speeds up to
500kbps. The MAX3076E/MAX3077E/MAX3078Es’ dri-
ver slew rates are not limited, making transmit speeds
up to 16Mbps possible. The MAX3079E’s slew rate is
selectable between 250kbps, 500kbps, and 16Mbps
by driving a selector pin with a three-state driver.
The MAX3072E/MAX3075E/MAX3078E are half-duplex
transceivers, while the MAX3070E/MAX3071E/
MAX3073E/MAX3074E/MAX3076E/MAX3077E are full-
duplex transceivers. The MAX3079E is selectable
between half- and full-duplex communication by driving
a selector pin (SRL) high or low, respectively.
All devices operate from a single 3.3V supply. Drivers are
output short-circuit current limited. Thermal-shutdown cir-
cuitry protects drivers against excessive power dissipa-
tion. When activated, the thermal-shutdown circuitry
places the driver outputs into a high-impedance state.
Receiver Input Filtering
The receivers of the MAX3070E–MAX3075E, and the
MAX3079E when operating in 250kbps or 500kbps
mode, incorporate input filtering in addition to input
hysteresis. This filtering enhances noise immunity with
differential signals that have very slow rise and fall
times. Receiver propagation delay increases by 25%
due to this filtering.
Fail-Safe
The MAX3070E family guarantees a logic-high receiver
output when the receiver inputs are shorted or open, or
when they are connected to a terminated transmission
line with all drivers disabled. This is done by setting the
receiver input threshold between -50mV and -200mV. If
the differential receiver input voltage (A - B) is greater
than or equal to -50mV, RO is logic high. If A - B is less
than or equal to -200mV, RO is logic low. In the case of
a terminated bus with all transmitters disabled, the
receiver’s differential input voltage is pulled to 0V by
the termination. With the receiver thresholds of the
MAX3070E family, this results in a logic high with a
50mV minimum noise margin. Unlike previous fail-safe
devices, the -50mV to -200mV threshold complies with
the ±200mV EIA/TIA-485 standard.
Hot-Swap Capability
(Except MAX3071E/MAX3074E/MAX3077E)
Hot-Swap Inputs
When circuit boards are inserted into a hot, or pow-
ered, backplane, differential disturbances to the data
bus can lead to data errors. Upon initial circuit board
insertion, the data communication processor under-
goes its own power-up sequence. During this period,
the processor’s logic-output drivers are high imped-
ance and are unable to drive the DE and RE inputs of
these devices to a defined logic level. Leakage cur-
rents up to ±10µA from the high-impedance state of the
processor’s logic drivers could cause standard CMOS
enable inputs of a transceiver to drift to an incorrect
logic level. Additionally, parasitic circuit board capaci-
tance could cause coupling of VCC or GND to the
enable inputs. Without the hot-swap capability, these
factors could improperly enable the transceiver’s driver
or receiver.
When VCC rises, an internal pulldown circuit holds DE
low and RE high. After the initial power-up sequence,
the pulldown circuit becomes transparent, resetting the
hot-swap tolerable input.
Hot-Swap Input Circuitry
The enable inputs feature hot-swap capability. At the
input there are two NMOS devices, M1 and M2
(Figure 9). When VCC ramps from zero, an internal 10µs
timer turns on M2 and sets the SR latch, which also
turns on M1. Transistors M2, a 500µA current sink, and
M1, a 100µA current sink, pull DE to GND through a
5kΩresistor. M2 is designed to pull DE to the disabled
state against an external parasitic capacitance up to
100pF that can drive DE high. After 10µs, the timer
deactivates M2 while M1 remains on, holding DE low
against three-state leakages that can drive DE high. M1
remains on until an external source overcomes the
required input current. At this time, the SR latch resets
and M1 turns off. When M1 turns off, DE reverts to a
standard, high-impedance CMOS input. Whenever VCC
drops below 1V, the hot-swap input is reset.
For RE there is a complementary circuit employing two
PMOS devices pulling RE to VCC.
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
MAX3070E–MAX3079E
Maxim Integrated
15
MAX3079E Programming
The MAX3079E has several programmable operating
modes. Transmitter rise and fall times are programma-
ble, resulting in maximum data rates of 250kbps,
500kbps, and 16Mbps. To select the desired data rate,
drive SRL to one of three possible states by using a
three-state driver: VCC, GND, or unconnected. For
250kbps operation, set the three-state device in high-
impedance mode or leave SRL unconnected. For
500kbps operation, drive SRL high or connect it to VCC.
For 16Mbps operation, drive SRL low or connect it to
GND. SRL can be changed during operation without
interrupting data communications.
Occasionally, twisted-pair lines are connected backward
from normal orientation. The MAX3079E has two pins that
invert the phase of the driver and the receiver to correct
this problem. For normal operation, drive TXP and RXP
low, connect them to ground, or leave them unconnect-
ed (internal pulldown). To invert the driver phase, drive
TXP high or connect it to VCC. To invert the receiver
phase, drive RXP high or connect it to VCC. Note that the
receiver threshold is positive when RXP is high.
The MAX3079E can operate in full- or half-duplex
mode. Drive the H/Fpin low, leave it unconnected
(internal pulldown), or connect it to GND for full-duplex
operation. Drive H/Fhigh for half-duplex operation. In
full-duplex mode, the pin configuration of the driver and
receiver is the same as that of a MAX3070E. In half-
duplex mode, the receiver inputs are switched to the
driver outputs, connecting outputs Y and Z to inputs A
and B, respectively. In half-duplex mode, the internal
full-duplex receiver input resistors are still connected to
pins 11 and 12.
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electro-
static discharges encountered during handling and
assembly. The driver outputs and receiver inputs of the
MAX3070E family of devices have extra protection
against static electricity. Maxim’s engineers have devel-
oped state-of-the-art structures to protect these pins
against ESD of ±15kV without damage. The ESD struc-
tures withstand high ESD in all states: normal operation,
shutdown, and powered down. After an ESD event, the
MAX3070E–MAX3079E keep working without latchup or
damage.
ESD protection can be tested in various ways. The
transmitter outputs and receiver inputs of the
MAX3070E–MAX3079E are characterized for protection
to the following limits:
•±15kV using the Human Body Model
•±6kV using the Contact Discharge method specified
in IEC 1000-4-2
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Human Body Model
Figure 10a shows the Human Body Model, and Figure
10b shows the current waveform it generates when dis-
charged into a low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
which is then discharged into the test device through a
1.5kΩresistor.
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and
performance of finished equipment. However, it does
not specifically refer to integrated circuits. The
MAX3070E family of devices helps you design equip-
ment to meet IEC 1000-4-2, without the need for addi-
tional ESD-protection components.
The major difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
DE DE
(HOT SWAP)
5kΩ
TIMER
TIMER
VCC
10μs
M2M1
500μA
100μA
SR LATCH
Figure 9. Simplified Structure of the Driver Enable Pin (DE)
MAX3070E–MAX3079E
16
Maxim Integrated
current in IEC 1000-4-2, because series resistance is
lower in the IEC 1000-4-2 model. Hence, the ESD with-
stand voltage measured to IEC 1000-4-2 is generally
lower than that measured using the Human Body Model.
Figure 10c shows the IEC 1000-4-2 model, and Figure
10d shows the current waveform for IEC 1000-4-2 ESD
Contact Discharge test.
The air-gap test involves approaching the device with a
charged probe. The contact-discharge method connects
the probe to the device before the probe is energized.
Machine Model
The machine model for ESD tests all pins using a
200pF storage capacitor and zero discharge resis-
tance. The objective is to emulate the stress caused
when I/O pins are contacted by handling equipment
during test and assembly. Of course, all pins require
this protection, not just RS-485 inputs and outputs.
Applications Information
256 Transceivers on the Bus
The standard RS-485 receiver input impedance is 12kΩ
(1-unit load), and the standard driver can drive up to 32-
unit loads. The MAX3070E family of transceivers has a
1/8-unit load receiver input impedance (96kΩ), allowing
up to 256 transceivers to be connected in parallel on one
communication line. Any combination of these devices
as well as other RS-485 transceivers with a total of 32-
unit loads or fewer can be connected to the line.
Reduced EMI and Reflections
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 offer higher driver
output slew-rate limits, allowing transmit speeds up to
500kbps. The MAX3079E with SRL = VCC or uncon-
nected, are slew-rate limited. With SRL unconnected,
the MAX3079E error-free data transmission is up to
250kbps; with SRL connected to VCC the data transmit
speeds up to 500kbps.
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
RC
1MΩ
RD
1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 10a. Human Body ESD Test Model
IP 100%
90%
36.8%
tRL TIME
tDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPS
Figure 10b. Human Body Current Waveform
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
150pF
RC
50MΩ TO 100MΩ
RD
330Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 10c. IEC 1000-4-2 ESD Test Model
tr = 0.7ns TO 1ns 30ns
60ns
t
100%
90%
10%
I
PEAK
I
Figure 10d. IEC 1000-4-2 ESD Generator Current Waveform
MAX3070E–MAX3079E
Maxim Integrated
17
Low-Power Shutdown Mode (Except
MAX3071E/MAX3074E/MAX3077E)
Low-power shutdown mode is initiated by bringing both
RE high and DE low. In shutdown, the devices typically
draw only 50nA of supply current.
RE and DE can be driven simultaneously; the parts are
guaranteed not to enter shutdown if RE is high and DE
is low for less than 50ns. If the inputs are in this state
for at least 600ns, the parts are guaranteed to enter
shutdown.
Enable times tZH and tZL (see the
Switching
Characteristics
section) assume the part was not in a
low-power shutdown state. Enable times tZH(SHDN) and
tZL(SHDN) assume the parts were shut down. It takes
drivers and receivers longer to become enabled from
low-power shutdown mode (tZH(SHDN), tZL(SHDN)) than
from driver/receiver-disable mode (tZH, tZL).
Driver Output Protection
Two mechanisms prevent excessive output current and
power dissipation caused by faults or by bus contention.
The first, a foldback current limit on the output stage,
provides immediate protection against short circuits over
the whole common-mode voltage range (see the
Typical
Operating Characteristics
). The second, a thermal-shut-
down circuit, forces the driver outputs into a high-imped-
ance state if the die temperature becomes excessive.
Line Length
The RS-485/RS-422 standard covers line lengths up to
4000ft. For line lengths greater than 4000ft, use the
repeater application shown in Figure 11.
Typical Applications
The MAX3072E/MAX3075E/MAX3078E/MAX3079E
transceivers are designed for bidirectional data commu-
nications on multipoint bus transmission lines. Figures
12 and 13 show typical network applications circuits.
To minimize reflections, terminate the line at both ends
in its characteristic impedance, and keep stub lengths
off the main line as short as possible. The slew-rate-lim-
ited MAX3072E/MAX3075E and the two modes of the
MAX3079E are more tolerant of imperfect termination.
Chip Information
TRANSISTOR COUNT: 1228
PROCESS: BiCMOS
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
RO
DI
DE
R
D
MAX3070E/MAX3071E/MAX3073E/
MAX3074E/MAX3076E/MAX3077E/
MAX3079E (FULL-DUPLEX)
RE 120Ω
120Ω
A
B
Z
Y
DATA IN
DATA OUT
Figure 11. Line Repeater for MAX3070E/MAX3071E/MAX3073E/
MAX3074E/MAX3076E/MAX3077E/MAX3079E in Full-Duplex
Mode
DI RO DE
A
B
RE
RO
RO
RO
DI
DI
DI
DE
DE
DE
DD
D
R
R
R
BB
B
AAA
120Ω120Ω
D
R
MAX3072E
MAX3075E
MAX3078E
MAX3079E (HALF-DUPLEX) RERE
RE
Figure 12. Typical Half-Duplex RS-485 Network
MAX3070E–MAX3079E
18
Maxim Integrated
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
RO
DI
DE
R120Ω
120Ω
D
MAX3070E
MAX3073E
MAX3076E
MAX3079E (FULL-DUPLEX)
RE
RO
DI
DE
R
D
RE
120Ω
120Ω
A
B
Z
Y
A
B
Z
Y
RO
DI DE
R
D
RE
YZBA
RO
DI DE
R
D
RE
YZBA
Figure 13. Typical Full-Duplex RS-485 Network
Selector Guide
PART HALF/FULL-
DUPLEX
DATA RATE
(Mbps)
SLEW-RATE
LIMITED
LOW-POWER
SHUTDOWN
RECEIVER/
DRIVER
ENABLE
TRANSCEIVERS
ON BUS PINS
MAX3070E Full 0.250 Yes Yes Yes 256 14
MAX3071E Full 0.250 Yes No No 256 8
MAX3072E Half 0.250 Yes Yes Yes 256 8
MAX3073E Full 0.5 Yes Yes Yes 256 14
MAX3074E Full 0.5 Yes No No 256 8
MAX3075E Half 0.5 Yes Yes Yes 256 8
MAX3076E Full 16 No Yes Yes 256 14
MAX3077E Full 16 No No No 256 8
MAX3078E Half 16 No Yes Yes 256 8
MAX3079E Selectable Selectable Selectable Yes Yes 256 14
MAX3070E–MAX3079E
Maxim Integrated
19
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
MAX3070E
MAX3073E
MAX3076E
Rt
Rt
DE VCC
RE
GND
VCC RE
GND DE
RO
DI
9
10
12
11
B
A
Z
Y
0.1μF
5
RO
N.C.
DI
2
1, 8, 13
36, 7
14
4
VCC
N.C.
N.C.
A
B
Z
Y
N.C.
RO
RE
DE
DI
GND
GND
D
D
RD
R
TYPICAL FULL-DUPLEX OPERATING CIRCUIT
14
13
12
11
10
9
8
1
2
3
4
5
6
7
DIP/SO
R
Pin Configurations and Typical Operating Circuits
MAX3071E
MAX3074E
MAX3077E
Rt
Rt
VCC
GND
VCC
GND
RO
DI
5
6
8
7
B
A
Z
Y
0.1μF
3
RO
DI
2
4
1
R
D
D
RD
R
TYPICAL FULL-DUPLEX OPERATING CIRCUIT
VCC
RO
DI
GND
A
B
Z
Y
8
7
6
5
1
2
3
4
DIP/SO
MAX3072E
MAX3075E
MAX3078E
Rt
Rt
DE
RE
B
A
B
A
0.1μF
TYPICAL HALF-DUPLEX OPERATING CIRCUIT
NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORMS DIAGRAMS.
REFER TO PINS A AND B WHEN DE IS HIGH.
R
D
RO
DI
VCC
B
A
GND
8
7
6
5
1
2
3
4
DIP/SO
RE
DE
R
D
RO
DI
VCC
GND
8
7
6
5
1
2
3
4
RE
DE
D
R
DI
RO
MAX3070E–MAX3079E
20
Maxim Integrated
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
14
13
12
11
10
9
8
1
2
3
4
5
6
7
MAX3079E
MAX3079E
DIP/SO
TOP VIEW
VCC
VCC
RXP
TXP
A
B
Z
Y
RO
DE
DI
SRL
GND
RE
H/F
RO
TXP
A
B
Z
Y
GND DE SRL
DI
H/F
RXP
NOTE: SWITCH POSITIONS
INDICATED FOR H/F = GND.
RE
Pin Configurations and Typical Operating Circuits (continued)
MAX3070E–MAX3079E
Maxim Integrated
21
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
Ordering Information (continued)
PART† TEMP RANGE PIN-PACKAGE
MAX3072EEPA -40°C to +85°C 8 Plastic DIP
MAX3072EESA -40°C to +85°C 8 SO
MAX3072EAPA -40°C to +125°C 8 Plastic DIP
MAX3072EASA -40°C to +125°C 8 SO
MAX3073EEPD -40°C to +85°C 14 Plastic DIP
MAX3073EESD -40°C to +85°C 14 SO
MAX3073EAPD -40°C to +125°C 14 Plastic DIP
MAX3073EASD -40°C to +125°C 14 SO
MAX3074EEPA -40°C to +85°C 8 Plastic DIP
MAX3074EESA -40°C to +85°C 8 SO
MAX3074EAPA -40°C to +125°C 8 Plastic DIP
MAX3074EASA -40°C to +125°C 8 SO
MAX3075EEPA -40°C to +85°C 8 Plastic DIP
MAX3075EESA -40°C to +85°C 8 SO
MAX3075EAPA -40°C to +125°C 8 Plastic DIP
MAX3075EASA -40°C to +125°C 8 SO
PART† TEMP RANGE PIN-PACKAGE
MAX3076EEPD -40°C to +85°C 14 Plastic DIP
MAX3076EESD -40°C to +85°C 14 SO
MAX3076EAPD -40°C to +125°C 14 Plastic DIP
MAX3076EASD -40°C to +125°C 14 SO
MAX3077EEPA -40°C to +85°C 8 Plastic DIP
MAX3077EESA -40°C to +85°C 8 SO
MAX3077EAPA -40°C to +125°C 8 Plastic DIP
MAX3077EASA -40°C to +125°C 8 SO
MAX3077EMSA/PR -55°C to +125°C 8 SO
MAX3078EEPA -40°C to +85°C 8 Plastic DIP
MAX3078EESA -40°C to +85°C 8 SO
MAX3078EAPA -40°C to +125°C 8 Plastic DIP
MAX3078EASA -40°C to +125°C 8 SO
MAX3079EEPD -40°C to +85°C 14 Plastic DIP
MAX3079EESD -40°C to +85°C 14 SO
MAX3079EAPD -40°C to +125°C 14 Plastic DIP
MAX3079EASD -40°C to +125°C 14 SO
†Devices are available in both leaded (Pb) and lead(Pb)-free
packaging. Specify lead-free by adding a “+” after the part
number.
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
8 Plastic DIP P8-2 21-0043
14 Plastic DIP P14-3
8 SO S8-4 21-0041
14 SO S14-1
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the
package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the
package regardless of RoHS status.
MAX3070E–MAX3079E
22
Maxim Integrated
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
Package Information (continued)
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the
package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the
package regardless of RoHS status.
SOICN .EPS
PACKAGE OUTLINE, .150" SOIC
1
1
21-0041 B
REV.DOCUMENT CONTROL NO.APPROVAL
PROPRIETARY INFORMATION
TITLE:
TOP VIEW
FRONT VIEW
MAX
0.010
0.069
0.019
0.157
0.010
INCHES
0.150
0.007
E
C
DIM
0.014
0.004
B
A1
MIN
0.053A
0.19
3.80 4.00
0.25
MILLIMETERS
0.10
0.35
1.35
MIN
0.49
0.25
MAX
1.75
0.050
0.016L0.40 1.27
0.3940.386D
D
MINDIM
D
INCHES
MAX
9.80 10.00
MILLIMETERS
MIN MAX
16 AC
0.337 0.344 AB8.758.55 14
0.189 0.197 AA5.004.80 8
N MS012
N
SIDE VIEW
H 0.2440.228 5.80 6.20
e 0.050 BSC 1.27 BSC
C
HE
eBA1
A
D
0\-8\
L
1
VARIATIONS:
MAX3070E–MAX3079E
Maxim Integrated
23
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 10/02 Initial release. —
2 4/09
Added /PR information to reflect new characterization information for military
temperature version.
2, 3, 7, 8, 12, 13, 19,
22–25
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
MAX3070E–MAX3079E
24 Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
© 2009 Maxim Integrated The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.