19-1138; Rev 1; 12/97
Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
MAX3080–MAX3089
General Description
The MAX3080–MAX3089 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. This means that
the receiver output will be a logic high if all transmitters
on a terminated bus are disabled (high impedance).
The MAX3080/MAX3081/MAX3082 feature reduced
slew-rate drivers that minimize EMI and reduce reflec-
tions caused by improperly terminated cables, allowing
error-free data transmission up to 115kbps. The
MAX3083/MAX3084/MAX3085 offer higher driver out-
put slew-rate limits, allowing transmit speeds up to
500kbps. The MAX3086/MAX3087/MAX3088’s driver
slew rates are not limited, making transmit speeds up
to 10Mbps possible. The MAX3089’s slew rate is
selectable between 115kbps, 500kbps, and 10Mbps
by driving a selector pin with a single three-state
driver.
These transceivers typically draw 375µA of supply
current when unloaded, or when fully loaded with the
drivers disabled.
All devices have a 1/8-unit-load receiver input imped-
ance that allows up to 256 transceivers on the bus. The
MAX3082/MAX3085/MAX3088 are intended for half-
duplex communications, while the MAX3080/MAX3081/
MAX3083/MAX3084/MAX3086/MAX3087 are intended
for full-duplex communications. The MAX3089 is selec-
table between half-duplex and full-duplex operation. It
also features independently programmable receiver
and transmitter output phase via separate pins.
Features
o
True Fail-Safe Receiver While Maintaining
EIA/TIA-485 Compatibility
o
Enhanced Slew-Rate Limiting Facilitates
Error-Free Data Transmission
(MAX3080–MAX3085/MAX3089)
o
1nA Low-Current Shutdown Mode (except
MAX3081/MAX3084/MAX3087)
o
Pin-Selectable Full/Half-Duplex Operation
(MAX3089)
o
Phase Controls to Correct for Twisted-Pair
Reversal (MAX3089)
o
Allow Up to 256 Transceivers on the Bus
Applications
RS-422/RS-485 Communications
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
Ordering Information
PART
MAX3080CPD
MAX3080CSD
MAX3080EPD
MAX3080ESD
TEMP. RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
14 Plastic DIP
14 SO
14 Plastic DIP
14 SO
Ordering Information continued on last page.
Selection Table
Part
MAX3080
MAX3081
MAX3082
MAX3083
MAX3084
MAX3085
MAX3086
MAX3087
MAX3088
MAX3089
Half/Full
Duplex
Full
Full
Half
Full
Full
Half
Full
Full
Half
Selectable
Data
Rate
(Mbps)
0.115
0.115
0.115
0.5
0.5
0.5
10
10
10
Selectable
Slew
Rate
Limited
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
Selectable
Low-
Power
Shutdown
Yes
No
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Receiver/
Driver
Enable
Yes
No
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Quiescent Transceivers
Current
On
(µA)
Bus
375
375
375
375
375
375
375
375
375
375
256
256
256
256
256
256
256
256
256
256
Pin
Count
14
8
8
14
8
8
14
8
8
14
Industry-
Standard
Pinout
75180
75179
75176
75180
75179
75176
75180
75179
75176
75180*
*Pin-compatible with 75180, with additional features implemented using pins 1, 6, 8, and 13.
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
MAX3080–MAX3089
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
) ............................................................+7V
Control Input Voltage (RE,
DE)...................-0.3V to (V
CC
+ 0.3V)
Special Input Voltage
(H/F, SRL, TXP, RXP)..................................-0.3V to (V
CC
+ 0.3V)
Driver Input Voltage (DI).............................-0.3V to (V
CC
+ 0.3V)
Driver Output Voltage (A, B, Y, Z)........................................±13V
Receiver Input Voltage (A, B) ..............................................±13V
Receiver Input Voltage, Full Duplex (A, B) ..........................±25V
Receiver Output Voltage (RO)....................-0.3V to (V
CC
+ 0.3V)
Continuous Power Dissipation
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ...727mW
8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
14-Pin Plastic DIP (derate 10.0mW/°C above +70°C) ....800mW
14-Pin SO (derate 8.33mW/°C above +70°C)..............667mW
Operating Temperature Ranges
MAX308_C_ _ .....................................................0°C to +70°C
MAX308_E_ _...................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+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
= +5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.) (Note 1)
PARAMETER
DRIVER
Differential Driver Output
(no load)
Differential Driver Output
Change in Magnitude of
Differential Output Voltage
(Note 2)
Driver Common-Mode Output
Voltage
Change In Magnitude of
Common-Mode Voltage (Note 2)
Input High Voltage
Input Low Voltage
DI Input Hysteresis
SRL Input Current
Input High Voltage
Input Middle Voltage
Input Low Voltage
SRL Input Current
Input Current (A and B)
Full Duplex
Output Leakage (Y and Z)
Full Duplex
Driver Short-Circuit Output
Current (Note 4)
2
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
OD1
V
OD2
∆V
OD
V
OC
∆V
OC
V
IH1
V
IL1
V
HYS
I
IN1
I
IN2
V
IH2
V
IM2
V
IL2
I
IN3
I
IN4
I
O
Figure 5
Figure 5, R = 50Ω (RS-422)
Figure 5, R = 27Ω (RS-485)
Figure 5, R = 50Ω or R = 27Ω
Figure 5, R = 50Ω or R = 27Ω
Figure 5, R = 50Ω or R = 27Ω
DE, DI,
RE,
H/F, TXP, RXP
DE, DI,
RE,
H/F, TXP, RXP
MAX3080–MAX3085, and MAX3089 with
SRL = V
CC
or unconnected
DE, DI,
RE
H/F, TXP, RXP, internal pull-down
SRL
SRL (Note 3)
SRL
SRL = V
CC
SRL = GND (Note 3)
DE = GND,
V
CC
= GND or 5.25V
DE = GND,
V
CC
= GND or 5.25V
-7V
≤
V
OUT
≤
V
CC
0V
≤
V
OUT
≤
12V
0V
≤
V
OUT
≤
V
CC
V
IN
= 12V
V
IN
= -7V
V
IN
= 12V
V
IN
= -7V
-100
-250
-75
10
V
CC
- 0.8
0.4V
CC
2.0
2.0
1.5
5
V
V
0.2
3
0.2
V
V
V
V
0.8
100
±2
40
0.6V
CC
0.8
75
125
-75
125
V
mV
µA
V
V
V
µA
µA
µA
V
OD1
250
±25
mA
_______________________________________________________________________________________
Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.) (Note 1)
PARAMETER
RECEIVER
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
Receiver Output High Voltage
Receiver Output Low Voltage
Three-State Output Current at
Receiver
Receiver Input Resistance
Receiver Output Short-Circuit
Current
SUPPLY CURRENT
No load,
RE
= DI = GND
or V
CC
, SRL = V
CC
No load,
RE
= DI = GND
or V
CC
, SRL = GND
DE = GND, V
RE
= V
CC
DE = V
CC
DE = GND
DE = V
CC
DE = GND
430
375
475
420
0.001
900
µA
600
1000
µA
800
10
µA
SYMBOL
CONDITIONS
-7V
≤
V
CM
≤
12V
I
O
= -4mA, V
ID
= -50mV
I
O
= 4mA, V
ID
= -200mV
0.4V
≤
V
O
≤
2.4V
-7V
≤
V
CM
≤
12V
0V
≤
V
RO
≤
V
CC
96
±7
±95
MIN
TYP
MAX
UNITS
MAX3080–MAX3089
V
TH
∆V
TH
V
OH
V
OL
I
OZR
R
IN
I
OSR
-200
V
CC
-1.5
-125
25
-50
mV
mV
V
V
µA
kΩ
mA
0.4
±1
Supply Current
I
CC
Supply Current in Shutdown
Mode
I
SHDN
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
∆V
OC
are the changes in V
OD
and V
OC
, respectively, when the DI input changes state.
Note 3:
The SRL pin is internally biased to V
CC
/ 2 by a 100kΩ/100kΩ resistor divider. It is guaranteed to be V
CC
/ 2 if left
unconnected.
Note 4:
Maximum current level applies to peak current just prior to foldback-current limiting; minimum current level applies during
current limiting.
_______________________________________________________________________________________
3
Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
MAX3080–MAX3089
SWITCHING CHARACTERISTICS—MAX3080–MAX3082, and MAX3089 with
SRL = Unconnected
(V
CC
= +5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
Driver Input to Output
Driver Output Skew
|
t
DPLH
- t
DPHL
|
Driver Rise or Fall Time
Maximum Data Rate
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
Receiver Input to Output
SYMBOL
t
DPLH
t
DPHL
t
DSKEW
t
DR
, t
DF
f
MAX
t
DZH
t
DZL
t
DLZ
t
DHZ
t
RPLH
,
t
RPHL
t
RSKD
t
RZL
t
RZH
t
RLZ
t
RHZ
t
SHDN
t
DZH(SHDN)
t
DZL(SHDN)
t
RZH(SHDN)
t
RZL(SHDN)
Figures 8 and 10, C
L
= 100pF, S2 closed
Figures 8 and 10, C
L
= 100pF, S1 closed
Figures 8 and 10, C
L
= 15pF, S1 closed
Figures 8 and 10, C
L
= 15pF, S2 closed
Figures 11 and 13;
|
V
ID
|
≥
2.0V;
rise and fall time of V
ID
≤
15ns
Figures 11 and 13;
|
V
ID
|
≥
2.0V;
rise and fall time of V
ID
≤
15ns
Figures 6 and 12, C
L
= 100pF, S1 closed
Figures 6 and 12, C
L
= 100pF, S2 closed
Figures 6 and 12, C
L
= 100pF, S1 closed
Figures 6 and 12, C
L
= 100pF, S2 closed
(Note 5)
Figures 8 and 10, C
L
= 15pF, S2 closed
Figures 8 and 10, C
L
= 15pF, S1 closed
Figures 6 and 12, C
L
= 100pF, S2 closed
Figures 6 and 12, C
L
= 100pF, S1 closed
50
127
3
20
20
20
20
200
CONDITIONS
Figures 7 and 9, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 7 and 9, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 7 and 9, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
667
115
3500
3500
100
100
200
±30
50
50
50
50
600
6000
6000
3500
3500
MIN
500
500
TYP
2030
2030
-3
1320
MAX
2600
2600
±200
2500
UNITS
ns
ns
ns
kbps
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
|
t
RPLH
- t
RPHL
|
Differential
Receiver Skew
Receiver Enable to Output Low
Receiver Enable to Output High
Receiver Disable Time from Low
Receiver Disable Time from
High
Time to Shutdown
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Receiver Enable from Shutdown
to Output High
Receiver Enable from Shutdown
to Output Low
4
_______________________________________________________________________________________
Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
SWITCHING CHARACTERISTICS—MAX3083–MAX3085, and MAX3089 with SRL = V
CC
(V
CC
= +5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
Driver Input to Output
Driver Output Skew
|
t
DPLH
- t
DPHL
|
Driver Rise or Fall Time
Maximum Data Rate
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
Receiver Input to Output
SYMBOL
t
DPLH
t
DPHL
t
DSKEW
t
DR,
t
DF
f
MAX
t
DZH
t
DZL
t
DLZ
t
DHZ
t
RPLH
,
t
RPHL
t
RSKD
t
RZL
t
RZH
t
RLZ
t
RHZ
t
SHDN
t
DZH(SHDN)
t
DZL(SHDN)
t
RZH(SHDN)
t
RZL(SHDN)
Figures 8 and 10, C
L
= 100pF, S2 closed
Figures 8 and 10, C
L
= 100pF, S1 closed
Figures 8 and 10, C
L
= 15pF, S1 closed
Figures 8 and 10, C
L
= 15pF, S2 closed
Figures 11 and 13;
|
V
ID
|
≥
2.0V;
rise and fall time of V
ID
≤
15ns
Figures 11 and 13;
|
V
ID
|
≥
2.0V;
rise and fall time of V
ID
≤
15ns
Figures 6 and 12, C
L
= 100pF, S1 closed
Figures 6 and 12, C
L
= 100pF, S2 closed
Figures 6 and 12, C
L
= 100pF, S1 closed
Figures 6 and 12, C
L
= 100pF, S2 closed
(Note 5)
Figures 8 and 10, C
L
= 15pF, S2 closed
Figures 8 and 10, C
L
= 15pF, S1 closed
Figures 6 and 12, C
L
= 100pF, S2 closed
Figures 6 and 12, C
L
= 100pF, S1 closed
50
127
3
20
20
20
20
200
CONDITIONS
Figures 7 and 9, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 7 and 9, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
Figures 7 and 9, R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF
200
500
2500
2500
100
100
200
±30
50
50
50
50
600
4500
4500
3500
3500
MIN
250
250
TYP
720
720
-3
530
MAX
1000
1000
±100
750
UNITS
ns
ns
ns
kbps
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
MAX3080–MAX3089
|
t
RPLH
- t
RPHL
|
Differential
Receiver Skew
Receiver Enable to Output Low
Receiver Enable to Output High
Receiver Disable Time from Low
Receiver Disable Time from
High
Time to Shutdown
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Receiver Enable from Shutdown
to Output High
Receiver Enable from Shutdown
to Output Low
_______________________________________________________________________________________
5
DSP 与 ARM 处理器
