Maxim MAX3483C 3.3v-powered, 10mbps and slew-rate-limited true rs-485/rs-422 transceiver Datasheet

MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
LE
AVAILAB
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
_______________General Description
The MAX3483, MAX3485, MAX3486, MAX3488,
MAX3490, and MAX3491 are 3.3V, low-power transceivers for RS-485 and RS-422 communication. Each
part contains one driver and one receiver. The
MAX3483 and MAX3488 feature slew-rate-limited drivers that minimize EMI and reduce reflections caused
by improperly terminated cables, allowing error-free
data transmission at data rates up to 250kbps. The partially slew-rate-limited MAX3486 transmits up to
2.5Mbps. The MAX3485, MAX3490, and MAX3491
transmit at up to 10Mbps.
Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal
shutdown circuitry that places the driver outputs into a
high-impedance state. The receiver input has a fail-safe
feature that guarantees a logic-high output if both
inputs are open circuit.
The MAX3488, MAX3490, and MAX3491 feature fullduplex communication, while the MAX3483, MAX3485,
and MAX3486 are designed for half-duplex communication.
________________________Applications
Low-Power RS-485/RS-422 Transceivers
____________________________Features
♦ Operate from a Single 3.3V Supply—
No Charge Pump!
♦ Interoperable with +5V Logic
♦ 8ns Max Skew (MAX3485/MAX3490/MAX3491)
♦ Slew-Rate Limited for Errorless Data Transmission
(MAX3483/MAX3488)
♦ 2nA Low-Current Shutdown Mode
(MAX3483/MAX3485/MAX3486/MAX3491)
♦ -7V to +12V Common-Mode Input Voltage Range
♦ Allows up to 32 Transceivers on the Bus
♦ Full-Duplex and Half-Duplex Versions Available
♦ Industry Standard 75176 Pinout
(MAX3483/MAX3485/MAX3486)
♦ Current-Limiting and Thermal Shutdown for
Driver Overload Protection
______________Ordering Information
PART
MAX3483CPA
Telecommunications
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
Functional Diagrams
MAX3483CSA
MAX3483C/D
MAX3483EPA
MAX3483ESA
MAX3485CPA
MAX3485CSA
MAX3485C/D
MAX3485EPA
MAX3485ESA
TEMP. RANGE
PIN-PACKAGE
0°C to +70°C
8 Plastic DIP
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
8 SO
Dice*
8 Plastic DIP
8 SO
8 Plastic DIP
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
8 SO
Dice*
8 Plastic DIP
8 SO
Ordering Information continued at end of data sheet.
* Contact factory for for dice specifications.
______________________________________________________________Selection Table
PART
NUMBER
GUARANTEED
DATA RATE
(Mbps)
MAX3483
MAX3485
SUPPLY
VOLTAGE
(V)
HALF/FULL
DUPLEX
SLEW-RATE
LIMITED
DRIVER/
RECEIVER
ENABLE
SHUTDOWN
CURRENT
(nA)
PIN
COUNT
0.25
Half
Yes
Yes
2
8
10
Half
No
Yes
2
8
Half
Yes
Yes
2
8
Full
Yes
No
—
8
Full
No
No
—
8
Full
No
Yes
2
14
MAX3486
2.5
3.0 to 3.6
PinMAX3488
Configurations appear
0.25 at end of data sheet.
Functional
Diagrams continued
at end of data sheet.
MAX3490
10
UCSP is a trademark of Maxim Integrated Products, Inc.
MAX3491
10
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-0333; Rev 0; 12/94
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC) ...............................................................7V
Control Input Voltage (RE, DE) ...................................-0.3V to 7V
Driver Input Voltage (DI) .............................................-0.3V to 7V
Driver Output Voltage (A, B, Y, Z)..........................-7.5V to 12.5V
Receiver Input Voltage (A, B) ................................-7.5V to 12.5V
Receiver Output Voltage (RO)....................-0.3V to (VCC + 0.3V)
Continuous Power Dissipation (TA = +70°C)
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 10mW/°C above +70°C) ......800mW
14-Pin SO (derate 8.33mW/°C above +70°C)................667mW
Operating Temperature Ranges
MAX34_ _C_ _.......................................................0°C to +70°C
MAX34_ _E_ _ ....................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°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
(VCC = 3.3V ±0.3V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C)
PARAMETER
Differential Driver Output
SYMBOL
VOD
CONDITIONS
MIN
RL = 100Ω (RS-422), Figure 4
2.0
RL = 60Ω (RS-485), VCC = 3.3V, Figure 5
1.5
RL = 54Ω (RS-485), Figure 4
TYP
MAX
UNITS
V
1.5
Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States
(Note 1)
∆VOD
RL = 54Ω or 100Ω, Figure 4
0.2
V
Driver Common-Mode Output
Voltage
VOC
RL = 54Ω or 100Ω, Figure 4
3
V
∆VOC
RL = 54Ω or 100Ω, Figure 4
0.2
V
Change in Magnitude of
Common-Mode Output Voltage
(Note 1)
Input High Voltage
Input Low Voltage
VIH
DE, DI, RE
2.0
V
DE, DI, RE
0.8
V
Logic Input Current
VIL
IIN1
DE, DI, RE
±2
µA
Input Current (A, B)
IIN2
DE = 0V,
VCC = 0V or 3.6V
Output Leakage (Y, Z)
IO
Output Leakage (Y, Z)
in Shutdown Mode
IO
Receiver Differential
Threshold Voltage
Receiver Input Hysteresis
Receiver Output High Voltage
Receiver Output Low Voltage
VTH
VIN = 12V
20
-20
VOUT = 12V
DE = 0V, RE = VCC,
VCC = 0V or 3.6V, MAX3491 VOUT = -7V
-7V ≤ VCM ≤ 12V
VCM = 0V
VOL
IOUT = 2.5mA, VID = 200mV, Figure 6
IOUT = -1.5mA, VID = 200mV, Figure 6
Three-State (High Impedance)
Output Current at Receiver
IOZR
VCC = 3.6V, 0V ≤ VOUT ≤ VCC
Receiver Input Resistance
RIN
-7V ≤ VCM ≤ 12V
2
-0.8
VOUT = 12V
DE = 0V, RE = 0V,
VCC = 0V or 3.6V, MAX3491 VOUT = -7V
∆VTH
VOH
1.0
VIN = -7V
1
-1
-0.2
0.2
50
VCC - 0.4
12
mA
µA
µA
V
mV
V
0.4
V
±1
µA
kΩ
Maxim Integrated
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(VCC = 3.3V ±0.3V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C)
PARAMETER
Supply Current
SYMBOL
ICC
Supply Current in Shutdown Mode
ISHDN
Driver Short-Circuit Output
Current
IOSD
Receiver Short-Circuit Output
Current
IOSR
CONDITIONS
No load,
DI = 0V or VCC
MIN
TYP
MAX
DE = VCC,
RE = 0V or VCC
1.1
2.2
DE = 0V,
RE = 0V
0.95
1.9
DE = 0V, RE = VCC, DI = VCC or 0V
0.002
VOUT = -7V
1
-250
VOUT = 12V
250
0V ≤ VRO ≤ VCC
±8
±60
UNITS
mA
µA
mA
mA
DRIVER SWITCHING CHARACTERISTICS—MAX3485, MAX3490, and MAX3491
(VCC = 3.3V, TA = +25°C)
PARAMETER
Driver Differential Output Delay
Driver Differential Output Transition Time
Driver Propagation Delay, Low-to-High Level
Driver Propagation Delay, High-to-Low Level
SYMBOL
CONDITIONS
tDD
RL = 60Ω, Figure 7
tPLH
RL = 27Ω, Figure 8
tTD
tPHL
RL = 60Ω, Figure 7
RL = 27Ω, Figure 8
tPDS
RL = 27Ω, Figure 8
|tPLH - tPHL| Driver Propagation Delay Skew (Note 2)
DRIVER OUTPUT ENABLE/DISABLE TIMES (MAX3485/MAX3491 only)
Driver Output Enable Time to Low Level
8
25
22
35
7
7
22
MAX
35
35
8
UNITS
ns
ns
ns
ns
ns
45
90
ns
tPHZ
RL = 110Ω, Figure 9
40
80
ns
Driver Output Disable Time from Low Level
tPLZ
Driver Output Enable Time from Shutdown to High Level
3
22
RL = 110Ω, Figure 10
tPZH
Driver Output Enable Time from Shutdown to Low Level
TYP
1
tPZL
Driver Output Enable Time to High Level
Driver Output Disable Time from High Level
MIN
tPSL
tPSH
RL = 110Ω, Figure 9
45
RL = 110Ω, Figure 10
40
RL = 110Ω, Figure 10
90
80
650
900
MIN
TYP
MAX
15
35
60
RL = 110Ω, Figure 9
650
900
ns
ns
ns
ns
DRIVER SWITCHING CHARACTERISTICS—MAX3486
(VCC = 3.3V, TA = +25°C)
PARAMETER
Driver Differential Output Delay
SYMBOL
CONDITIONS
tDD
RL = 60Ω, Figure 7
Driver Propagation Delay, Low-to-High Level
tPLH
RL = 27Ω, Figure 8
|tPLH - tPHL| Driver Propagation Delay Skew (Note 2)
tPDS
Driver Output Enable Time to High Level
tPZH
Driver Output Disable Time from Low Level
tPLZ
Driver Differential Output Transition Time
Driver Propagation Delay, High-to-Low Level
Driver Output Enable Time to Low Level
Driver Output Disable Time from High Level
Driver Output Enable Time from Shutdown to Low Level
Driver Output Enable Time from Shutdown to High Level
Maxim Integrated
tTD
tPHL
tPZL
tPHZ
tPSL
tPSH
RL = 60Ω, Figure 7
RL = 27Ω, Figure 8
RL = 27Ω, Figure 8
24
20
20
48
48
48
70
70
70
11
RL = 110Ω, Figure 10
55
100
RL = 110Ω, Figure 9
45
80
RL = 110Ω, Figure 9
RL = 110Ω, Figure 10
RL = 110Ω, Figure 10
RL = 110Ω, Figure 9
55
45
700
700
100
80
1000
1000
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
3
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
DRIVER SWITCHING CHARACTERISTICS—MAX3483 and MAX3488
(VCC = 3.3V, TA = +25°C)
PARAMETER
SYMBOL
Driver Differential Output Delay
Driver Differential Output Transition Time
Driver Propagation Delay, Low-to-High Level
Driver Propagation Delay, High-to-Low Level
RL = 60Ω, Figure 7
tPLH
RL = 27Ω, Figure 8
tTD
tPHL
tPDS
|tPLH - tPHL| Driver Propagation Delay Skew (Note 2)
DRIVER OUTPUT ENABLE/DISABLE TIMES (MAX3483 only)
Driver Output Enable Time to Low Level
RL = 27Ω, Figure 8
RL = 27Ω, Figure 8
TYP
400
700
600
700
700
900
1000
1000
100
MAX
1400
1200
1500
1500
ns
ns
ns
ns
ns
900
1300
ns
tPHZ
RL = 110Ω, Figure 9
50
80
ns
Driver Output Disable Time from Low Level
tPLZ
tPSL
RL = 110Ω, Figure 9
600
RL = 110Ω, Figure 10
50
80
2.7
MIN
TYP
MAX
MAX3483/MAX3485/MAX3486/MAX3491 only
(Note 3)
80
190
300
VID = 0V to 3.0V, CL = 15pF, Figure 11
25
65
VID = 0V to 3.0V, CL = 15pF, Figure 11
25
65
tPSH
RL = 110Ω, Figure 10
800
1.9
Driver Output Enable Time from Shutdown to High Level
UNITS
RL = 110Ω, Figure 10
tPZH
Driver Output Enable Time from Shutdown to Low Level
RL = 60Ω, Figure 7
MIN
tPZL
Driver Output Enable Time to High Level
Driver Output Disable Time from High Level
CONDITIONS
tDD
RL = 110Ω, Figure 9
2.2
3.0
ns
ns
µs
µs
RECEIVER SWITCHING CHARACTERISTICS
(VCC = 3.3V, TA = +25°C)
PARAMETER
SYMBOL
CONDITIONS
UNITS
Time to Shutdown
tSHDN
Receiver Propagation Delay,
Low-to-High Level
tRPLH
Receiver Propagation Delay,
High-to-Low Level
tRPHL
|tPLH - tPHL| Receiver
Propagation Delay Skew
tRPDS
Receiver Output Enable Time
to Low Level
tPRZL
CL = 15pF, Figure 12,
MAX3483/MAX3485/MAX3486/MAX3491 only
25
50
ns
Receiver Output Enable Time
to High Level
tPRZH
CL = 15pF, Figure 12,
MAX3483/MAX3485/MAX3486/MAX3491 only
25
50
ns
Receiver Output Disable
Time from High Level
tPRHZ
CL = 15pF, Figure 12,
MAX3483/MAX3485/MAX3486/MAX3491 only
25
45
ns
Receiver Output Disable
Time from Low Level
tPRLZ
CL = 15pF, Figure 12,
MAX3483/MAX3485/MAX3486/MAX3491 only
25
45
ns
Receiver Output Enable Time
from Shutdown to Low Level
tPRSL
CL = 15pF, Figure 12,
MAX3483/MAX3485/MAX3486/MAX3491 only
720
1400
ns
Receiver Output Enable Time
from Shutdown to High Level
tPRSH
CL = 15pF, Figure 12,
MAX3483/MAX3485/MAX3486/MAX3491 only
720
1400
ns
MAX3483/MAX3488
MAX3483/MAX3488
VID = 0V to 3.0V, CL = 15pF, Figure 11
25
25
90
75
120
75
120
MAX3483/MAX3488
90
10
20
ns
ns
ns
ns
Note 1: ∆VOD and ∆VOC are the changes in VOD and VOC, respectively, when the DI input changes state.
Note 2: Measured on |tPLH (Y) - tPHL (Y)| and |tPLH (Z) - tPHL (Z)|.
Note 3: The transceivers are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 80ns, the
parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 300ns, the parts are guaranteed to
have entered shutdown. See Low-Power Shutdown Mode section.
4
Maxim Integrated
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
__________________________________________Typical Operating Characteristics
(VCC = 3.3V, TA = +25°C, unless otherwise noted.)
-18
10
-14
-12
-10
-8
-6
-4
5
1.0
1.5
2.0
3.0
0
3.5
0
0.5
1.0
1.5
2.0
2.5
3.0
OUTPUT HIGH VOLTAGE (V)
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
DRIVER OUTPUT CURRENT vs.
DIFFERENTIAL OUTPUT VOLTAGE
100
90
OUTPUT CURRENT (mA)
0.7
0.6
0.5
0.4
0.3
0.2
70
60
50
40
30
20
10
0
0
-20
0
20
40
60
80
100
0
0.5
TEMPERATURE (°C)
1.0
1.5
2.0
2.5
3.0
DIFFERENTIAL OUTPUT VOLTAGE (V)
OUTPUT CURRENT vs.
DRIVER OUTPUT LOW VOLTAGE
125
100
75
50
20
40
60
80
100
3.5
2.6
R = 54Ω
2.5
2.4
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
-80
-60
-40
-20
25
0
0
0
2
4
6
8
10
OUTPUT LOW VOLTAGE (V)
Maxim Integrated
0
-100
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
150
-20
OUTPUT CURRENT vs.
DRIVER OUTPUT HIGH VOLTAGE
MAX3483-07
175
-40
MAX3483-08
-40
3.10
DRIVER DIFFERENTIAL OUTPUT
VOLTAGE vs.TEMPERATURE
80
0.1
3.15
3.00
3.5
MAX3483-05
IRO = 2.5mA
3.20
TEMPERATURE (°C)
OUTPUT LOW VOLTAGE (V)
0.8
OUTPUT LOW VOLTAGE (V)
2.5
DIFFERENTIAL OUTPUT VOLTAGE (V)
0.5
MAX3483-04
0
3.25
3.05
-2
0
IRO = 1.5mA
MAX3483-06
15
-16
OUTPUT HIGH VOLTAGE (V)
OUTPUT CURRENT (mA)
20
3.30
MAX3483-02
-20
MAX3483-01
25
OUTPUT CURRENT (mA)
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
OUTPUT CURRENT vs.
RECEIVER OUTPUT HIGH VOLTAGE
MAX3483-03
OUTPUT CURRENT vs.
RECEIVER OUTPUT LOW VOLTAGE
12
-7 -6 -5 -4 -3 -2 -1 0 1 2 3
OUTPUT HIGH VOLTAGE (V)
4
5
5
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
_____________________________Typical Operating Characteristics (continued)
SHUTDOWN CURRENT
vs. TEMPERATURE
SUPPLY CURRENT
vs. TEMPERATURE
90
1.1
DE = VCC, RE = X
1.0
DE = 0, RE = 0
0.9
MAX3483-10
100
MAX3483-09
X = DON’T CARE
SHUTDOWN CURRENT (nA)
SUPPLY CURRENT (mA)
1.2
0.8
80
70
60
50
40
30
20
10
0.7
0
-40
-20
0
20
40
60
80
100
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
TEMPERATURE (°C)
______________________________________________________________Pin Description
PIN
6
MAX3483/
MAX3485/
MAX3486
MAX3488/
MAX3490
MAX3491
1
2
2
—
NAME
FUNCTION
2
RO
Receiver Output. If A > B by 200mV, RO will be high; if A < B by 200mV,
RO will be low.
3
–
RE
Receiver Output Enable. RO is enabled when RE is low; RO is high impedance when RE is high. If RE is high and DE is low, the device will enter a
low-power shutdown mode.
3
—
4
DE
Driver Output Enable. The driver outputs are enabled by bringing DE high.
They are high impedance when DE is low. If RE is high and DE is low, the
device will enter a low-power shutdown mode. If the driver outputs are
enabled, the parts function as line drivers. While they are high impedance,
they function as line receivers if RE is low.
4
3
5
DI
Driver Input. A low on DI forces output Y low and output Z high. Similarly, a
high on DI forces output Y high and output Z low.
5
4
6, 7
GND
—
5
9
Y
Noninverting Driver Output
—
6
10
Z
Inverting Driver Output
6
—
—
A
Noninverting Receiver Input and Noninverting Driver Output
—
8
12
A
Noninverting Receiver Input
7
—
—
B
Inverting Receiver Input and Inverting Driver Output
—
7
11
B
Inverting Receiver Input
8
1
13, 14
VCC
Positive Supply: 3.0V ≤ VCC ≤ 3.6V
—
—
1, 8
N.C.
No Connect—not internally connected
Ground
Maxim Integrated
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
TOP VIEW
RO
1
RE 2
DE 3
DI 4
R
D
1
VCC
RO
7
B
RE 2
6
A
DE 3
5
GND
DI 4
8
R
MAX3483
MAX3485
MAX3486
8 VCC
7 B
Rt
6
A
5 GND
D
DE
D
B
DI
Rt
A
RO
R
DIP/SO
RE
NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM DIAGRAMS REFER TO PINS A AND B WHEN DE IS HIGH.
Figure 1. MAX3483/MAX3485/MAX3486 Pin Configuration and Typical Operating Circuit
VCC
VCC
TOP VIEW
MAX3488
MAX3490
1
8
A
RO 2
7
B
DI 3
6
Z
5
Y
VCC 1
GND 4
R
D
DI
RO
3
5 Y
D
Rt
6 Z
R
RO
8 A
2
R
Rt
7
D
DI
B
DIP/SO
4
GND
GND
Figure 2. MAX3488/MAX3490 Pin Configuration and Typical Operating Circuit
TOP VIEW
DE
4
VCC
13, 14
14 V CC
N.C.
1
RO
2
RE
3
12 A
DE
4
11 B
DI
5
GND
6
GND
7
R
D
13 V CC
10 Z
9 Y
8 N.C.
DIP/SO
9
DI
5
D
VCC RE
MAX3491
Y
Rt
10
R
RO
Z
RO
12
2
R
A
Rt
11
D
DI
B
N.C.
1, 8
3
6, 7
RE GND
GND
DE
Figure 3. MAX3491 Pin Configuration and Typical Operating Circuit
Maxim Integrated
7
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
375Ω
RL
2
VCM =
-7V to +12V
VOD
D
D
RL
2
VCC
VOD
RL
VOC
VCC
Figure 4. Driver VOD and VOC
VID
375Ω
Figure 5. Driver VOD with Varying Common-Mode Voltage
R
0V
VOL
IOL
(+)
VOH
IOH
(-)
Figure 6. Receiver VOH and VOL
3V
IN
1.5V
1.5V
CL
D
GENERATOR
(NOTE 4)
0V
RL =
60Ω
OUT
tDO
50Ω
VCC
OUT
CL
CL = 15pF (NOTE 5)
50%
10%
tTD
tDO
90%
≈
90%
50%
10%
2.0V
≈ -2.0V
tTD
Figure 7. Driver Differential Output Delay and Transition Times
8
Maxim Integrated
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
3V
VOM
IN
1.5V
1.5V
RL = 27Ω
0V
S1
GENERATOR
(NOTE 4)
tPLH
OUT
D
50Ω
CL = 15pF
(NOTE 5)
VCC
VOM =
VOH + VOL
2
tPHL
VOH
Y
OUT
VOM
VOM
VOL
tPHL
≈ 1.5V
tPLH
VOH
Z
OUT
VOM
VOM
VOL
Figure 8. Driver Propagation Times
3V
S1
0V OR 3V
GENERATOR
(NOTE 4)
OUT
D
IN
0V
RL = 110Ω
CL = 50pF
(NOTE 5)
1.5V
1.5V
tPZH
tPHZ
50Ω
0.25V
OUT
VOH + VOL
VOM =
2
VOH
VOM
≈ 1.5V
0V
Figure 9. Driver Enable and Disable Times (tPZH, tPSH, tPHZ)
VCC
S1
0V OR 3V
3V
RL = 110Ω
IN
1.5V
1.5V
0V
OUT
D
tPSL
GENERATOR
(NOTE 4)
CL = 50pF
(NOTE 5)
50Ω
tPLZ
VCC
OUT
VOM
0.25V
VOL
Figure 10. Driver Enable and Disable Times (tPZL, tPSL, tPLZ)
Maxim Integrated
9
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
3.0V
GENERATOR
(NOTE 4)
VID
OUT
R
50Ω
IN
CL = 15pF
(NOTE 5)
1.5V
1.5V
0V
tRPLH
tRPHL
VCC
1.5V
VOM =
0V
VOM
OUT
VCC
2
VOM
0V
Figure 11. Receiver Propagation Delay
S1
S3
1.5V
1k
-1.5V
VID
VCC
R
S2
CL
(NOTE 5)
GENERATOR
(NOTE 4)
50Ω
3V
IN
1.5V
0V
3V
S1 OPEN
S2 CLOSED
S3 = 1.5V
IN
0V
tPRZH
tPRSH
tPRZL
tPRSL
VOH
OUT
VCC
OUT
1.5V
1.5V
0V
VOL
3V
IN
S1 CLOSED
S2 OPEN
S3 = -1.5V
1.5V
1.5V
0V
3V
S1 OPEN
S2 CLOSED
S3 = 1.5V
IN
S1 CLOSED
S2 OPEN
S3 = -1.5V
1.5V
0V
tPRHZ
OUT 0.25V
tPRLZ
VOH
OUT
0V
VCC
0.25V
VOL
Figure 12. Receiver Enable and Disable Times
Note 4: The input pulse is supplied by a generator with the following characteristics: PRR = 250kHz, 50% duty cycle, tr ≤ 6.0ns, ZO = 50Ω.
Note 5: CL includes probe and stray capacitance.
10
Maxim Integrated
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
____________________Function Tables
Devices with Receiver/Driver Enable
(MAX3483/MAX3485/MAX3486/MAX3491)
Table 1. Transmitting
INPUTS
OUTPUTS
RE
DE
DI
B*
A*
X
1
0
1
0
X
1
0
1
0
1
0
X
0
High-Z
X
High-Z
MODE
1
Normal
High-Z
Normal
High-Z
Normal
Shutdown
* B and A outputs are Z and Y, respectively, for full-duplex part
(MAX3491).
X = Don’t care; High-Z = High impedance
Table 2. Receiving
INPUTS
RE
DE
0
0*
0
0
1
OUTPUTS
A, B
RO
≤ -0.2V
0
0*
≥ +0.2V
0*
Inputs Open
0
1
Normal
Normal
1
X
MODE
High-Z
Normal
Shutdown
* DE is a “don’t care” (x) for the full-duplex part (MAX3491).
X = Don’t care; High-Z = High impedance
Devices without Receiver/Driver Enable
(MAX3488/MAX3490)
Table 3. Transmitting
INPUT
DI
1
0
Table 4. Receiving
OUTPUTS
INPUTS
OUTPUT
0
≥ +0.2V
1
Z
Y
1
0
A, B
1
RO
≤ -0.2V
0
Inputs Open
1
10dB/div
0Hz
The MAX3483/MAX3485/MAX3486/MAX3488/MAX3490/
MAX3491 are low-power transceivers for RS-485 and
RS-422 communications. The MAX3483 and MAX3488
can transmit and receive at data rates up to 250kbps,
the MAX3486 at up to 2.5Mbps, and the MAX3485/
MAX3490/MAX3491 at up to 10Mbps. The MAX3488/
MAX3490/MAX3491 are full-duplex transceivers, while
the MAX3483/MAX3485/MAX3486 are half-duplex.
Driver Enable (DE) and Receiver Enable (RE) pins are
included on the MAX3483/MAX3485/MAX3486/
MAX3491. When disabled, the driver and receiver outputs are high impedance.
Reduced EMI and Reflections
(MAX3483/MAX3486/MAX3488)
The MAX3483/MAX3488 are slew-rate limited, minimizing EMI and reducing reflections caused by improperly
terminated cables. Figure 13 shows both the driver
output waveform of a MAX3485/MAX3490/MAX3491
transmitting a 125kHz signal and the Fourier analysis of
that waveform. High-frequency harmonics with large
amplitudes are evident. Figure 14 shows the same information, but for the slew-rate-limited MAX3483/MAX3488
transmitting the same signal. The high-frequency harmonics have much lower amplitudes, and the potential for
EMI is significantly reduced.
Low-Power Shutdown Mode
(MAX3483/MAX3485/MAX3486/MAX3491)
A low-power shutdown mode is initiated by bringing both
RE high and DE low. The devices will not shut down
unless both the driver and receiver are disabled (high
impedance). In shutdown, the devices typically draw
only 2nA of supply current.
For these devices, the t PSH and t PSL enable times
assume the part was in the low-power shutdown mode;
the tPZH and tPZL enable times assume the receiver or
driver was disabled, but the part was not shut down.
10dB/div
500kHz/div
5MHz
Figure 13. Driver Output Waveform and FFT Plot of MAX3485/
MAX3490/MAX3491 Transmitting a 125kHz Signal
Maxim Integrated
__________Applications Information
0Hz
500kHz/div
5MHz
Figure 14. Driver Output Waveform and FFT Plot of MAX3483/
MAX3488 Transmitting a 125kHz Signal
11
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
B
1V/div
DI
2V/div
A
1V/div
Z
1V/div
RO
2V/div
Y
1V/div
20ns/div
20ns/div
Figure 15. MAX3485/MAX3490/MAX3491 Driver Propagation
Delay
Figure 16. MAX3485/MAX3490/MAX3491 Receiver
Propagation Delay Driven by External RS-485 Device
B
1V/div
DI
2V/div
A
1V/div
Z
1V/div
Y
1V/div
RO
2V/div
1µs/div
1µs/div
Figure 17. MAX3483/MAX3488 Driver Propagation Delay
DI
5V/div
DI
5V/div
VY - VZ
2V/div
VY - VZ
2V/div
RO
5V/div
RO
5V/div
2µs/div
Figure 19. MAX3483/MAX3488 System Differential Voltage at
125kHz Driving 4000 ft of Cable
12
Figure 18. MAX3483/MAX3488 Receiver Propagation Delay
2µs/div
Figure 20. MAX3485/MAX3490/MAX3491 System Differential
Voltage at 125kHz Driving 4000 ft of Cable
Maxim Integrated
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
120Ω
120Ω
DI
DE
B
B
D
D
DI
DE
A
B
A
B
A
A
R
R
RO
RE
RO
RE
R
MAX3483
MAX3485
MAX3486
R
D
D
DI
DE
RO RE
DI
DE
RO RE
Figure 21. MAX3483/MAX3485/MAX3486 Typical RS-485 Network
Driver Output Protection
Excessive output current and power dissipation caused
by faults or by bus contention are prevented by two
mechanisms. A foldback current limit on the output stage
provides immediate protection against short circuits over
the whole common-mode voltage range (see Typical
Operating Characteristics). In addition, a thermal shutdown circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively.
Propagation Delay
Figures 15–18 show the typical propagation delays. Skew
time is simply the difference between the low-to-high and
high-to-low propagation delay. Small driver/receiver
skew times help maintain a symmetrical mark-space
ratio (50% duty cycle).
The receiver skew time, |tPRLH - tPRHL|, is under 10ns
(20ns for the MAX3483/MAX3488). The driver skew
times are 8ns for the MAX3485/MAX3490/MAX3491,
11ns for the MAX3486, and typically under 100ns for
the MAX3483/MAX3488.
Maxim Integrated
Line Length vs. Data Rate
The RS-485/RS-422 standard covers line lengths up to
4000 feet. For line lengths greater than 4000 feet, see
Figure 23.
Figures 19 and 20 show the system differential voltage
for parts driving 4000 feet of 26AWG twisted-pair wire
at 125kHz into 120Ω loads.
Typical Applications
The MAX3483, MAX3485, MAX3486, MAX3488,
MAX3490, and MAX3491 transceivers are designed for
bidirectional data communications on multipoint bus
transmission lines. Figures 21 and 22 show typical network applications circuits. These parts can also be
used as line repeaters, with cable lengths longer than
4000 feet, as shown in Figure 23.
To minimize reflections, the line should be terminated at
both ends in its characteristic impedance, and stub
lengths off the main line should be kept as short as
possible. The slew-rate-limited MAX3483/MAX3488
and the partially slew-rate-limited MAX3486 are more
tolerant of imperfect termination.
13
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
A
R
RO
RE
Y
120Ω
120Ω
Z
Z
B
DE
120Ω
D
DI
D
B
Y
120Ω
Z
Y
B
A
Y
Z
R
A
DE RE RO
DE
R
RE
RO
A
R
D
D
DI
B
DI
DI
DE RE RO
MAX3488
MAX3490
MAX3491
NOTE: RE AND DE ON MAX3491 ONLY.
Figure 22. MAX3488/MAX3490/MAX3491 Full-Duplex RS-485 Network
A
RO
RE
R
B
MAX3488
MAX3490
MAX3491
120Ω
DATA IN
DE
DI
Z
D
Y
120Ω
DATA OUT
NOTE: RE AND DE ON MAX3491 ONLY.
Figure 23. Line Repeater for MAX3488/MAX3490/MAX3491
14
Maxim Integrated
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
_Ordering Information (continued)
PART
MAX3486CPA
MAX3486CSA
MAX3486C/D
MAX3486EPA
MAX3486ESA
MAX3488CPA
MAX3488CSA
MAX3488C/D
MAX3488EPA
MAX3488ESA
MAX3490CPA
MAX3490CSA
MAX3490C/D
MAX3490EPA
MAX3490ESA
MAX3491CPD
MAX3491CSD
MAX3491C/D
MAX3491EPD
MAX3491ESD
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
__________________ Chip Topography
V CC
PIN-PACKAGE
8 Plastic DIP
8 SO
Dice*
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
Dice*
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
Dice*
8 Plastic DIP
8 SO
14 Plastic DIP
14 SO
Dice*
14 Plastic DIP
14 SO
RO
A
RE
B
Z/B
0.146"
(3.71mm)
DE
DI
Y/A
GND
* Contact factory for for dice specifications.
GND
0.086"
(2.18mm)
TRANSISTOR COUNT: 810
SUBSTRATE CONNECTED TO GROUND
Maxim Integrated
15
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True RS-485/RS-422 Transceivers
________________________________________________________Package Information
DIM
D
0°-8°
A
0.101mm
0.004in.
e
B
A1
C
E
L
SO
SMALL OUTLINE
PACKAGE
(0.150 in.)
H
D
L A1
B1
B
A
A1
A2
A3
B
B1
C
D1
E
E1
e
eA
eB
L
C
eA
eB
Plastic DIP
PLASTIC
DUAL-IN-LINE
PACKAGE
(0.300 in.)
8
14
16
MILLIMETERS
MIN
MAX
1.35
1.75
0.10
0.25
0.35
0.49
0.19
0.25
3.80
4.00
1.27
5.80
6.20
0.40
1.27
INCHES
MILLIMETERS
MIN MAX
MIN
MAX
0.189 0.197 4.80
5.00
0.337 0.344 8.55
8.75
0.386 0.394 9.80 10.00
21-0041A
E1
D1
16
D
D
D
DIM
0° - 15°
e
DIM PINS
E
A3
A A2
A
A1
B
C
E
e
H
L
INCHES
MAX
MIN
0.069
0.053
0.010
0.004
0.019
0.014
0.010
0.007
0.157
0.150
0.050
0.244
0.228
0.050
0.016
INCHES
MAX
MIN
0.200
–
–
0.015
0.175
0.125
0.080
0.055
0.022
0.016
0.065
0.045
0.012
0.008
0.080
0.005
0.325
0.300
0.310
0.240
–
0.100
–
0.300
0.400
–
0.150
0.115
DIM PINS
D
D
D
D
D
D
8
14
16
18
20
24
INCHES
MIN
MAX
0.348 0.390
0.735 0.765
0.745 0.765
0.885 0.915
1.015 1.045
1.14 1.265
MILLIMETERS
MIN
MAX
–
5.08
0.38
–
3.18
4.45
1.40
2.03
0.41
0.56
1.14
1.65
0.20
0.30
0.13
2.03
7.62
8.26
6.10
7.87
2.54
–
7.62
–
–
10.16
2.92
3.81
MILLIMETERS
MIN
MAX
8.84
9.91
18.67 19.43
18.92 19.43
22.48 23.24
25.78 26.54
28.96 32.13
Maxim Integrated
MAX3483/MAX3485/MAX3486/
MAX3488/MAX3490/MAX3491
3.3V-Powered, 10Mbps and Slew-Rate-Limited
True 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. 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.
Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
©
Maxim Integrated
17
The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.