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, guaranteeing 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 reflections caused by improperly terminated cables, allowing
error-free data transmission up to 250kbps. The
MAX3073E/MAX3074E/MAX3075E also feature slewrate-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
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-2668; Rev 1; 1/03
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Selector Guide, Pin Configurations, and Typical Operating
Circuits appear at end of data sheet.
Ordering Information continued at end of data sheet.
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
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(VCC= 3.3V ±10%, TA=T
MIN
to T
MAX
, 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 (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
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
DRIVER
Differential Driver Output V
Change in Magnitude of
Differential Output Voltage
Driver Common-Mode Output
Voltage
Change in Magnitude of
Common-Mode Voltage
Input High Voltage V
Input Low Voltage V
Input Hysteresis V
Input Current I
Input Impedance First Transition DE 1 10 kΩ
Input Current I
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 Input Current
Output Leakage (Y and Z)
Full Duplex
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
RL = 100Ω (RS422), Figure 1 2 V
RL = 54Ω (RS485), Figure 1 1.5 V
No load V
RL = 100Ω or 54Ω, Figure 1 (Note 2) 0.2 V
OD
RL = 100Ω or 54Ω, Figure 1 V
RL = 100Ω or 54Ω, Figure 1 (Note 2) 0.2 V
OC
DE, DI, RE, TXP, RXP, H/F 2V
IH
DE, DI, RE, TXP, RXP, H/F 0.8 V
IL
DE, DI, RE, TXP, RXP, H/F 100 mV
DE, DI, RE ±1µA
TXP, RXP, H/F internal pulldown 10 40 µA
SRL = V
SRL = GND -75
DE = GND,
O
V
CC
= GND or 3.6V
CC
VIN = +12V 125
V
= -7V -100
IN
∆V
V
∆V
OD
OC
HYS
IN1
IN2
I
CC
CC
CC
CC
/ 2 3 V
75
V
µA
µA
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
_______________________________________________________________________________________ 3
DC ELECTRICAL CHARACTERISTICS (continued)
(VCC= 3.3V ±10%, TA=T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= 3.3V and TA= +25°C.) (Note 1)
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: ∆V
OD
and ∆VOCare the changes in VODand 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.
Driver Short-Circuit Output
Current
Driver Short-Circuit Foldback
Output Current
Thermal-Shutdown Threshold T
Thermal-Shutdown Hysteresis T
Input Current (A and B) I
RECEIVER
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis ∆V
RO Output High Voltage V
RO Output Low Voltage V
Three-State Output Current at
Receiver
Receiver Input Resistance R
Receiver Output Short-Circuit
Current
SUPPLY CURRENT
Supply Current I
Supply Current in Shutdown
Mode
ESD PROTECTION
ESD Protection for Y, Z, A, and B Human Body Model ±15 kV
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
I
OSD
I
OSDF
TSH
A, B
V
OH
I
OZR
I
OSR
CC
I
SHDN
0 ≤ V
-7V ≤ V
(VCC - 1V) ≤ V
-7V ≤ V
TS
DE = GND,
V
-7V ≤ VCM ≤ 12V -200 -125 -50 mV
TH
VA + VB = 0V 15 mV
TH
IO = -1mA VCC - 0.6 V
IO = 1mA 0.4 V
OL
0 ≤ VO ≤ V
-7V ≤ VCM ≤ 12V 96 kΩ
IN
0V ≤ VRO ≤ V
No load, RE = 0, DE = V
No load, RE = VCC, DE = V
No load, RE = 0, DE = 0 0.8 1.5
RE = VCC, DE = GND 0.05 10 µA
≤ 12V (Note 3) 40 250
OUT
≤ VCC (Note 3) -250 -40
OUT
≤ 12V (Note 3) 20
OUT
≤ 1V (Note 3) -20
OUT
VIN = +12V 125
= GND or 3.6
CC
CC
CC
CC
CC
V
= -7V -100
IN
175 °C
15 °C
± 1µA
±80 mA
0.8 1.5
0.8 1.5
mA
mA
µA
mA
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
4 _______________________________________________________________________________________
DRIVER SWITCHING CHARACTERISTICS
MAX3070E/MAX3071E/MAX3072E/MAX3079E with SRL = UNCONNECTED (250kbps)
(VCC= 3.3V ±10%, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= 3.3V and TA= +25°C.)
)
)
RECEIVER SWITCHING CHARACTERISTICS
MAX3070E/MAX3071E/MAX3072E/MAX3079E with SRL = UNCONNECTED (250kbps)
(VCC= 3.3V ±10%, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= 3.3V and TA= +25°C.)
)
)
Driver Propagation Delay
Driver Differential Output Rise or
Fall Time
Differential Driver Output Skew
|t
DPLH
Maximum Data Rate 250 kbps
Driver Enable to Output High t
Driver Enable to Output Low t
Driver Disable Time from Low t
Driver Disable Time from High t
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Time to Shutdown t
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
- t
|
DPHL
t
DPLH
t
DPHL
t
DR , tDFCL
t
DSKEW
DZH
DZL
DLZ
DHZ
t
DZH(SHDN
t
DZL(SHDN
SHDN
CL= 50pF, RL= 54Ω, Figures 2 and 3
= 50pF, RL= 54Ω, Figures 2 and 3 350 1600 ns
CL= 50pF, RL= 54Ω, Figures 2 and 3 200 ns
Figure 4 2500 ns
Figure 5 2500 ns
Figure 5 100 ns
Figure 4 100 ns
Figure 4 5500 ns
Figure 5 5500 ns
250 1500
250 1500
50 200 600 ns
ns
Receiver Propagation Delay
Receiver Output Skew
|t
RPLH
Maximum Data Rate 250 kbps
Receiver Enable to Output Low t
Receiver Enable to Output High t
Receiver Disable Time from Low t
Receiver Disable Time from High t
Receiver Enable from Shutdown
to Output High
Receiver Enable from Shutdown
to Output Low
Time to Shutdown t
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
- t
|
RPHL
t
RPLH
t
RPHL
t
RSKEW
RZL
RZH
RLZ
RHZ
t
RZH(SHDN
t
RZL(SHDN
SHDN
CL = 15pF, Figures 6 and 7
CL = 15pF, Figures 6 and 7 30 ns
Figure 8 50 ns
Figure 8 50 ns
Figure 8 50 ns
Figure 8 50 ns
Figure 8 4000 ns
Figure 8 4000 ns
200
200
50 200 600 ns
ns
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
_______________________________________________________________________________________ 5
DRIVER SWITCHING CHARACTERISTICS
MAX3073E/MAX3074E/MAX3075E/MAX3079E with SRL = VCC(500kbps)
(VCC= 3.3V ±10%, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= 3.3V and TA= +25°C.)
)
)
RECEIVER SWITCHING CHARACTERISTICS
MAX3073E/MAX3074E/MAX3075E/MAX3079E with SRL = VCC(500kbps)
(VCC= 3.3V ±10%, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= 3.3V and TA= +25°C.)
)
)
Driver Propagation Delay
Driver Differential Output Rise or
Fall Time
Differential Driver Output Skew
|t
DPLH
Maximum Data Rate 500 kbps
Driver Enable to Output High t
Driver Enable to Output Low t
Driver Disable Time from Low t
Driver Disable Time from High t
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Time to Shutdown t
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
- t
|
DPHL
t
DPLH
t
DPHL
t
DR , tDFCL
t
DSKEW
DZH
DZL
DLZ
DHZ
t
DZH(SHDN
t
DZL(SHDN
SHDN
CL = 50pF, RL = 54Ω, Figures 2 and 3
= 50pF, RL = 54Ω, Figures 2 and 3 200 800 ns
CL = 50pF, RL = 54Ω, Figures 2 and 3 100 ns
Figure 4 2500 ns
Figure 5 2500 ns
Figure 5 100 ns
Figure 4 100 ns
Figure 4 4500 ns
Figure 5 4500 ns
180 800
180 800
50 200 600 ns
ns
Receiver Propagation Delay
Receiver Output Skew
|t
RPLH
Maximum Data Rate 500 kbps
Receiver Enable to Output Low t
Receiver Enable to Output High t
Receiver Disable Time from Low t
Receiver Disable Time from High t
Receiver Enable from Shutdown
to Output High
Receiver Enable from Shutdown
to Output Low
Time to Shutdown t
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
- t
|
RPHL
t
RPLH
t
RPHL
t
RSKEWCL
RZL
RZH
RLZ
RHZ
t
RZH(SHDN
t
RZL(SHDN
SHDN
CL = 15pF, Figures 6 and 7
= 15pF, Figures 6 and 7 30 ns
Figure 8 50 ns
Figure 8 50 ns
Figure 8 50 ns
Figure 8 50 ns
Figure 8 4000 ns
Figure 8 4000 ns
200
200
50 200 600 ns
ns
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
6 _______________________________________________________________________________________
DRIVER SWITCHING CHARACTERISTICS
MAX3076E/MAX3077E/MAX3078E/MAX3079E with SRL = GND (16Mbps)
(VCC= 3.3V ±10%, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= 3.3V and TA= +25°C.)
)
)
RECEIVER SWITCHING CHARACTERISTICS
MAX3076E/MAX3077E/MAX3078E/MAX3079E with SRL = GND (16Mbps)
(VCC= 3.3V ±10%, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at VCC= 3.3V and TA= +25°C.)
)
)
Driver Propagation Delay
Driver Differential Output Rise or
Fall Time
Differential Driver Output Skew
|t
DPLH
Maximum Data Rate 16 Mbps
Driver Enable to Output High t
Driver Enable to Output Low t
Driver Disable Time from Low t
Driver Disable Time from High t
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Time to Shutdown t
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
- t
|
DPHL
t
DPLH
t
DPHL
t
DR , tDFCL
t
DSKEW
DZH
DZL
DLZ
DHZ
t
DZH(SHDN
t
DZL(SHDN
SHDN
CL = 50pF, RL= 54Ω, Figures 2 and 3
= 50pF, RL= 54Ω, Figures 2 and 3 15 ns
CL = 50pF, RL= 54Ω, Figures 2 and 3 8 ns
Figure 4 150 ns
Figure 5 150 ns
Figure 5 100 ns
Figure 4 100 ns
Figure 4 1250 1800 ns
Figure 5 1250 1800 ns
50
50
50 200 600 ns
ns
Receiver Propagation Delay
Receiver Output Skew
|t
RPLH
Maximum Data Rate 16 Mbps
Receiver Enable to Output Low t
Receiver Enable to Output High t
Receiver Disable Time from Low t
Receiver Disable Time from High t
Receiver Enable from Shutdown
to Output High
Receiver Enable from Shutdown
to Output Low
Time to Shutdown t
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
- t
|
RPHL
t
RPLH
t
RPHL
t
RSKEWCL
RZL
RZH
RLZ
RHZ
t
RZH(SHDN
t
RZL(SHDN
SHDN
CL = 15pF, Figures 6 and 7
= 15pF, Figures 6 and 7 8 ns
Figure 8 50 ns
Figure 8 50 ns
Figure 8 50 ns
Figure 8 50 ns
Figure 8 1800 ns
Figure 8 1800 ns
40 75
40 75
50 200 600 ns
ns
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
_______________________________________________________________________________________ 7
Typical Operating Characteristics
(VCC= 3.3V, TA = +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
1.0
0.9
DE = V
0.8
0.7
SUPPLY CURRENT (mA)
0.6
0.5
-50 125
CC
DE = 0
TEMPERATURE (°C)
MAX3070E toc01
OUTPUT CURRENT (mA)
1007550250-25
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
3.30
3.25
3.20
3.15
3.10
OUTPUT HIGH VOLTAGE (V)
3.05
3.00
-50 125
TEMPERATURE (°C)
IO = -1mA
MAX3070E toc04
OUTPUT LOW VOLTAGE (V)
1007550250-25
vs. RECEIVER OUTPUT HIGH VOLTAGE
30
25
20
15
10
5
0
0 3.5
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-50 125
OUTPUT CURRENT
3.02.52.01.51.00.5
OUTPUT HIGH VOLTAGE (V)
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
IO = -1mA
10075-25 0 25 50
TEMPERATURE (°C)
35
30
MAX3070E toc02
25
20
15
OUTPUT CURRENT (mA)
10
5
0
100
90
80
MAX3070E toc05
70
60
50
40
30
OUTPUT CURRENT (mA)
20
10
0
vs. RECEIVER OUTPUT LOW VOLTAGE
OUTPUT CURRENT
0 3.5
OUTPUT HIGH VOLTAGE (V)
3.02.52.01.51.00.5
DRIVER OUTPUT CURRENT
vs. DIFFERENTIAL OUTPUT VOLTAGE
0 3.5
DIFFERENTIAL OUTPUT VOLTAGE (V)
3.02.51.5 2.01.00.5
MAX3070E toc03
MAX3070E toc06
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
2.60
2.50
2.40
2.30
2.20
2.10
2.00
1.90
1.80
DIFFERENTIAL OUTPUT VOLTAGE (V)
1.70
1.60
-50 125
TEMPERATURE (°C)
RL = 54Ω
1007525 500-25
160
140
XMAX3070E toc07
120
100
80
60
OUTPUT CURRENT (mA)
40
20
vs. TRANSMITTER OUTPUT HIGH VOLTAGE
OUTPUT CURRENT
0
-7 4
OUTPUT HIGH VOLTAGE (V)
32-6 -5 -4 -2 -1 0-3 1
180
160
MAX3070E toc08
140
120
100
80
60
OUTPUT CURRENT (mA)
40
20
0
vs. TRANSMITTER OUTPUT LOW VOLTAGE
OUTPUT CURRENT
MAX3070E toc09
012
OUTPUT LOW VOLTAGE (V)
108642
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
8 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VCC= 3.3V, TA = +25°C, unless otherwise noted.)
SHUTDOWN CURRENT
vs. TEMPERATURE
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
SHUTDOWN CURRENT (µA)
0.4
0.2
0
-50 125
TEMPERATURE (°C)
DRIVER PROPAGATION DELAY
vs. TEMPERATURE (250kbps)
1000
900
MAX3070E toc10
800
700
600
DRIVER PROPAGATION DELAY (ns)
500
1007525 500-25
-50 125
t
DPLH
t
DPHL
TEMPERATURE (°C)
MAX3070E toc11
DRIVER PROPAGATION DELAY (ns)
1007550250-25
DRIVER PROPAGATION DELAY
vs. TEMPERATURE (500kbps)
500
450
400
350
300
250
200
-50 125
t
DPLH
t
DPHL
TEMPERATURE (°C)
MAX3070E toc12
1007550250-25
DRIVER PROPAGATION DELAY
DRIVER PROPAGATION DELAY (ns)
vs. TEMPERATURE (16Mbps)
30
25
20
t
15
10
5
0
-50 125
DPLH
t
DPHL
TEMPERATURE (°C)
1007550250-25
MAX3070E toc13
DRIVER PROPAGATION DELAY (250kbps)
vs. TEMPERATURE (250kbps AND 500kbps)
150
120
90
60
30
DRIVER PROPAGATION DELAY (ns)
0
-50 125
MAX3070E toc16
RECEIVER PROPAGATION DELAY
t
DPLH
t
DPHL
1007550250-25
TEMPERATURE (°C)
RECEIVER PROPAGATION DELAY
DI
2V/div
V
- V
Y
Z
2V/div
RECEIVER PROPAGATION DELAY
vs. TEMPERATURE (16Mbps)
70
60
MAX3070E toc14
50
40
30
20
RECEIVER PROPAGATION DELAY (ns)
10
0
-50 125
(250kbps AND 500kbps)
t
DPLH
TEMPERATURE (°C)
MAX3070E toc17
- V
V
A
1V/div
RO
2V/div
t
DPHL
B
MAX3070E toc15
1007550250-25
1µs/div
200ns/div
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
_______________________________________________________________________________________ 9
Test Circuits and Waveforms
DRIVER PROPAGATION DELAY (500kbps)
MAX3070E toc18
400ns/div
V
Y
- V
Z
2V/div
DI
2V/div
DRIVER PROPAGATION DELAY (16Mbps)
MAX3070E toc19
10ns/div
V
Z
1V/div
V
Y
1V/div
DI
2V/div
RECEIVER PROPAGATION DELAY (16Mbps)
MAX3070E toc20
20ns/div
V
A
1V/div
V
B
1V/div
RO
2V/div
Typical Operating Characteristics (continued)
(VCC= 3.3V, TA = +25°C, unless otherwise noted.)
Figure 1. Driver DC Test Load
Figure 2. Driver Timing Test Circuit
Figure 3. Driver Propagation Delays
Y
RL/2
V
OD
RL/2
V
OC
3V
DE
DI
Y
R
V
OD
Z
C
L
L
Z
V
CC
DI
VCC/2
0
Z
V
O
Y
1/2 V
O
V
O
V
0
DIFF
10%
t
DR
-V
O
t
DPLH
V
= V (Y) - V (Z)
DIFF
90%
t
SKEW = | tDPLH - tDPHL
t
|
DPHL
1/2 V
O
90%
t
DF
10%
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
10 ______________________________________________________________________________________
Test Circuits and Waveforms (continued)
Figure 4. Driver Enable and Disable Times (t
DHZ
, t
DZH
, t
DZH(SHDN)
)
Figure 5. Driver Enable and Disable Times (t
DZL
, t
DLZ
, t
DLZ(SHDN)
)
S1
0 OR 3V
D
C
L
50pF
R
= 500Ω
L
OUT
OUT
GENERATOR
DE
t
, t
DZH
DZH(SHDN)
VOM = (0 + VOH) / 2
50Ω
0 OR 3V
D
V
CC
V
/ 2
CC
0
0.25V
t
DHZ
V
OH
0
V
CC
= 500Ω
R
S1
C
L
50pF
L
OUT
GENERATOR
DE
, t
t
DZL
DZL(SHDN)
V
CC
OUT
V
OL
VOM = (VOL + VCC) / 2
50Ω
V
/ 2
CC
t
DLZ
V
CC
0
0.25V
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
______________________________________________________________________________________ 11
Test Circuits and Waveforms (continued)
Figure 6. Receiver Propagation Delay Test Circuit
Figure 7. Receiver Propagation Delays
Figure 8. Receiver Enable and Disable Times
B
ATE
V
ID
R
A
+1.5V
-1.5V
S1 OPEN
S2 CLOSED
S3 = +1.5V
RE
RO
S3
GENERATOR
t
RZH
RECEIVER
OUTPUT
, t
RZH(SHDN)
A
B
t
S1
S2
S1 CLOSED
S2 OPEN
S3 = -1.5V
RPLH
t
RZL
V
CC
, t
RZL(SHDN)
1.5V
(VOL + VCC) / 2
3V
0
V
CC
V
OL
V
ID
VOH / 2
V
OH
1.5V
V
RO
OL
THE RISE TIME AND FALL TIME OF INPUTS A AND B < 4ns
C
15pF
1kΩ
L
RE
RO
R
50Ω
3V
0
V
OH
0
t
RPHL
+1V
-1V
S1 OPEN
S2 CLOSED
S3 = +1.5V
RE
0.25V
RO
1.5V
t
RHZ
S1 CLOSED
S2 OPEN
3V
0
V
OH
0
RE
t
RLZ
RO
S3 = -1.5V
1.5V
0.25V
3V
0
V
CC
V
OL
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
12 ______________________________________________________________________________________
Pin Description
PIN
MAX3070E
MAX3073E
MAX3076E
FULL-DUPLEX
MAX3071E
MAX3074E
MAX3077E
DEVICES
———11H/F
22122RO
3 — 233RE
MAX3072E
MAX3075E
MAX3078E
HALF-
DUPLEX
DEVICES
MAX3079E
FULL-
DUPLEX
MODE
HALF-
DUPLEX
MODE
4 — 344DE
53455DI
———6 6 SRL
6, 7 4 5 7 7 GND Ground
———8 8 TXP
95— 9 — Y Noninverting Driver Output
— ———9Y
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
NAME FUNCTION
Half-/Full-Duplex Select Pin. Connect H/F to V
duplex mode; connect to GND or leave unconnected for
full-duplex mode.
Receiver Output. When RE is low and if (A - B) ≥ -50mV,
RO is high; if (A - B) ≤ -200mV, RO is low.
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).
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).
D r i ver Inp ut. W i th D E hi g h, a l ow on D I for ces noni nver ti ng
outp ut l ow and i nver ti ng outp ut hi g h. S i m i l ar l y, a hi g h on D I
for ces noni nver ti ng outp ut hi g h and i nver ti ng outp ut l ow .
Slew-Rate Limit Selector Pin. Connect SRL to ground for
16Mbps communication rate; connect to V
communication rate. Leave unconnected for 250kbps
communication rate.
Transmitter Phase. Connect TXP to ground or leave
floating for normal transmitter phase/polarity. Connect to
to invert the transmitter phase/polarity.
V
CC
Noninverting Driver Output and Noninverting Receiver
Input*
for half-
CC
for 500kbps
CC
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
______________________________________________________________________________________ 13
MAX3070E/MAX3073E/MAX3076E
Pin Description (continued)
*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.
MAX3071E/MAX3074E/MAX30767E
Function Tables
PIN
MAX3070E
MAX3073E
MAX3076E
FULL-DUPLEX
12 8 — 12 — A Noninverting Receiver Input
14 1 8 14 14 V
1, 8, 13 ————N.C.
MAX3071E
MAX3074E
MAX3077E
DEVICES
— ———12 A Receiver Input Resistors*
——6 ——A
———13 13 RXP
MAX3072E
MAX3075E
MAX3078E
HALF-
DUPLEX
DEVICES
MAX3079E
FULL-
DUPLEX
MODE
HALF-
DUPLEX
MODE
NAME FUNCTION
Noninverting Receiver Input and Noninverting Driver
Output
Receiver Phase. Connect RXP to GND or leave
unconnected for normal transmitter phase/polarity.
Connect to V
Positive Supply V
CC
with a 0.1µF capacitor.
No Connect. Not internally connected. Can be connected
to GND.
to invert receiver phase/polarity.
CC
= 3.3V ±10%. Bypass VCC to GND
CC
INPUTS OUTPUTS
RE DE DI Z Y
X1101
X1010
0 0 X High-Z High-Z
1 0 X Shutdown
INPUTS OUTPUT
RE DE A, B RO
0X≥ -50mV 1
0X≤ -200mV 0
0X
1 1 X High-Z
1 0 X Shutdown
TRANSMITTING
RECEIVING
Open/
shorted
1
INPUT OUTPUTS
DI Z Y
101
010
INPUTS OUTPUT
A, B RO
≥ -50mV 1
≤ -200mV 0
Open/shorted 1
TRANSMITTING
RECEIVING
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
14 ______________________________________________________________________________________
MAX3072E/MAX3075E/MAX3078E
Function Tables (continued)
MAX3079E
X = Don’t care; shutdown mode, driver and receiver outputs are high impedance.
INPUTS OUTPUTS
RE DE DI B/Z A/Y
X1101
X1010
0 0 X High-Z High-Z
1 0 X Shutdown
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
INPUTS OUTPUTS
H/F RXP 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
TRANSMITTING
RECEIVING
RECEIVING
INPUTS OUTPUTS
RE DE A-B RO
0X≥ -50mV 1
0X≤ -200mV 0
0X
1 1 X High-Z
1 0 X Shutdown
Open/
shorted
1
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 drivers disabled (see the Fail-Safe section). The
MAX3070E/MAX3072E/MAX3073E/MAX3075E/
MAX3076E/MAX3078E/MAX3079E also feature a hotswap capability allowing line insertion without erroneous 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’ driver 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 fullduplex 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 circuitry protects drivers against excessive power dissipation. 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 powered, backplane, differential disturbances to the data
bus can lead to data errors. Upon initial circuit board
insertion, the data communication processor undergoes its own power-up sequence. During this period,
the processor’s logic-output drivers are high impedance and are unable to drive the DE and RE inputs of
these devices to a defined logic level. Leakage currents 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 capacitance could cause coupling of V
CC
or GND to the
enable inputs. Without the hot-swap capability, these
factors could improperly enable the transceiver’s driver
or receiver.
When VCCrises, 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 V
CC
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
5kΩ resistor. 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 V
CC
drops below 1V, the hot-swap input is reset.
For RE there is a complementary circuit employing two
PMOS devices pulling RE to V
CC
.
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
______________________________________________________________________________________ 15
MAX3070E–MAX3079E
MAX3079E Programming
The MAX3079E has several programmable operating
modes. Transmitter rise and fall times are programmable, 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 highimpedance 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 unconnected (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/F pin low, leave it unconnected
(internal pulldown), or connect it to GND for full-duplex
operation. Drive H/F high 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 halfduplex 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 electrostatic 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 developed state-of-the-art structures to protect these pins
against ESD of ±15kV without damage. The ESD structures 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 discharged 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
1.5kΩ resistor.
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 equipment to meet IEC 1000-4-2, without the need for additional 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
16 ______________________________________________________________________________________
Figure 9. Simplified Structure of the Driver Enable Pin (DE)
V
CC
10µs
TIMER
SR LATCH
TIMER
DE
5kΩ
100µA
500µA
M2M1
DE
(HOT SWAP)
current in IEC 1000-4-2, because series resistance is
lower in the IEC 1000-4-2 model. Hence, the ESD withstand 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 resistance. 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 32unit 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 32unit 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 reflections 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 = V
CC
or unconnected, are slew-rate limited. With SRL unconnected,
the MAX3079E error-free data transmission is up to
250kbps; with SRL connected to V
CC
the data transmit
speeds up to 500kbps.
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
______________________________________________________________________________________ 17
HIGH-
Figure 10a. Human Body ESD Test Model
Figure 10b. Human Body Current Waveform
Figure 10c. IEC 1000-4-2 ESD Test Model
Figure 10d. IEC 1000-4-2 ESD Generator Current Waveform
VOLTAGE
DC
SOURCE
R
C
1MΩ
CHARGE-CURRENT-
LIMIT RESISTOR
C
100pF
R
D
s
1500Ω
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
AMPS
IP 100%
90%
36.8%
10%
0
0
t
RL
TIME
t
CURRENT WAVEFORM
I
r
DL
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
HIGH-
VOLTAGE
DC
SOURCE
R
C
50MΩ TO 100MΩ
CHARGE-CURRENT-
LIMIT RESISTOR
C
s
150pF
R
D
330Ω
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
I
100%
90%
PEAK
I
10%
tr = 0.7ns TO 1ns
30ns
60ns
t
MAX3070E–MAX3079E
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 tZHand tZL(see the Switching
Characteristics section) assume the part was not in a
low-power shutdown state. Enable times t
ZH(SHDN)
and
t
ZL(SHDN)
assume the parts were shut down. It takes
drivers and receivers longer to become enabled from
low-power shutdown mode (t
ZH(SHDN)
, t
ZL(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-shutdown circuit, forces the driver outputs into a high-impedance 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 communications 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-limited 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
18 ______________________________________________________________________________________
Figure 11. Line Repeater for MAX3070E/MAX3071E/MAX3073E/
MAX3074E/MAX3076E/MAX3077E/MAX3079E in Full-Duplex
Mode
Figure 12. Typical Half-Duplex RS-485 Network
MAX3070E/MAX3071E/MAX3073E/
MAX3074E/MAX3076E/MAX3077E/
RO
RE
DE
DI
R
D
MAX3079E (FULL-DUPLEX)
A
B
120Ω
Z
Y
120Ω
DATA IN
DATA OUT
120Ω 120Ω
DI
D
DE
RO
RE
MAX3079E (HALF-DUPLEX)
R
MAX3072E
MAX3075E
MAX3078E
B
BB
R
D
DI RO DE
DE
AAA
R
D
DI
RO
B
A
RERE
DE
D
DI
R
RO
RE
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
______________________________________________________________________________________ 19
Figure 13. Typical Full-Duplex RS-485 Network
Selector Guide
A
RO
RE
DE
DI
R
D
B
Z
Y
120Ω
120Ω
YZBA
D
YZBA
R
D
R
120Ω
120Ω
MAX3070E
MAX3071E
MAX3073E
Y
D
Z
B
R
A
MAX3074E
MAX3076E
DI
DE
RO
RE
NOTE: RE AND DE ON MAX3070E/MAX3073E/MAX3076E/MAX3079E ONLY.
DI
DE
RO
RE
MAX3079E (FULL-DUPLEX)
MAX3077E
TRANSCEIVERS
ON BUS
PART
HALF/FULL
DUPLEX
DATA RATE
(Mbps)
SLEW-RATE
LIMITED
LOW-POWER
SHUTDOWN
RECEIVER/
DRIVER
ENABLE
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
DI
DE
RE
RO
PINS
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
20 ______________________________________________________________________________________
Pin Configurations and Typical Operating Circuits
MAX3071E
MAX3074E
MAX3077E
Rt
Rt
V
CC
GND
V
CC
GND
RO
DI
5
6
8
7
B
A
Z
Y
0.1µF
3
RO
DI
2
4
1
R
D
D
R
D
R
TYPICAL FULL-DUPLEX OPERATING CIRCUIT
V
CC
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
V
CC
B
A
GND
8
7
6
5
1
2
3
4
DIP/SO
RE
DE
R
D
RO
DI
V
CC
GND
8
7
6
5
1
2
3
4
RE
DE
D
R
DI
RO
V
N.C.
RO
GND
GND
CC
DE
14
4
V
1
2
R
RE
3
DE
4
DI
5
6
7
D
14
CC
N.C.
13
A
12
B
11
Z
10
Y
9
N.C.
8
N.C.
DI
RO
1, 8, 13
5
D
2
R
GND
3
RE
0.1µF
Y
9
10
Z
12
A
11
B
6, 7
TYPICAL FULL-DUPLEX OPERATING CIRCUIT
DIP/SO
MAX3070E
MAX3073E
MAX3076E
Rt
V
CC RE
Rt
R
GND DE
RO
DI
D
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
______________________________________________________________________________________ 21
Pin Configurations and Typical Operating Circuits (continued)
TOP VIEW
H/F
1
RO
2
RE
3
DE
4
MAX3079E
DI
5
SRL
6
GND
7
DIP/SO
NOTE: SWITCH POSITIONS
INDICATED FOR H/F = GND.
V
RE
CC
MAX3079E
RO
14
V
CC
13
RXP
12
A
11
B
Z
10
Y
9
TXP
8
RXP
H/F
TXP
DI
GND DE SRL
A
B
Z
Y
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
22 ______________________________________________________________________________________
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
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
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
______________________________________________________________________________________ 23
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages
.)
9LUCSP, 3x3.EPS
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
24 ______________________________________________________________________________________
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages
.)
PDIPN.EPS
MAX3070E–MAX3079E
+3.3V, ±15kV ESD-Protected, Fail-Safe,
Hot-Swap, RS-485/RS-422 Transceivers
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 25
© 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages
.)
N
1
TOP VIEW
D
e
FRONT VIEW
INCHES
DIM
MIN
0.053A
0.004
A1
0.014
B
0.007
C
e 0.050 BSC 1.27 BSC
0.150
HE
A
B
A1
C
L
E
H 0.2440.228 5.80 6.20
0.016L
VARIATIONS:
INCHES
MINDIM
D
0.189 0.197 AA5.004.80 8
0.337 0.344 AB8.758.55 14
D
0-8
SIDE VIEW
MAX
0.069
0.010
0.019
0.010
0.157
0.050
MAX
0.3940.386D
MILLIMETERS
MAX
MIN
1.35
1.75
0.10
0.25
0.35
0.49
0.19
0.25
3.80 4.00
0.40 1.27
MILLIMETERS
MAX
MIN
9.80 10.00
N MS012
16
AC
SOICN .EPS
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
REV.DOCUMENT CONTROL NO.APPROVAL
21-0041
1
B
1
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