MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
General Description
Benefits and Features
The MAX3483AE and MAX3485AE are half-duplex transceivers.
The MAX3488AE, MAX3490AE, and MAX3491AE are
full-duplex transceivers. The MAX3483AE/85AE have a
1-unit load receiver input impedance, allowing up to 32
transceivers on the bus. The MAX3488AE/90AE/91AE
have a 1/4-unit load receiver input impedance, allowing up
to 128 transceivers on the bus. Each transceiver includes
a fail-safe receiver, ensuring that the receiver output (RO)
is high when inputs are shorted, open, or connected to a
three-state bus.
• Short-Circuit Protected Outputs
• True Fail-Safe Receiver Prevents False Transition
on Receiver Input Short or Open Events
• Hot-Swap Capability Eliminates False Transitions
During Power-Up or Hot Insertion
Devices in the MAX3483AE family (MAX3483AE/
MAX3485AE/MAX3488AE/MAX3490AE/MAX3491AE)
are ±20kV ESD-protected RS-485/422 transceivers,
optimized for extended cable runs in noisy environments.
All devices operate from a single 3.3V supply.
All devices feature enhanced electrostatic discharge (ESD)
protection. All transmitter outputs and receiver inputs are
protected to ±20kV HBM ESD, ±15kV Air-Gap ESD and
±8kV Contact ESD in accordance to IEC 61000-4-2.
The MAX3483AE, MAX3485AE, MAX3488AE, and
MAX3490AE are available in industry standard 8-pin SO
package, while the MAX3491AE is available in a 14-pin
SO package.
Functional Diagram
19-8506; Rev 1; 9/17
● Integrated Protection Increases Robustness
• High ESD Protection
±20kV HBM ESD per JEDEC JS-001-2012
±15kV Air Gap per IEC 61000-4-2
±8kV Contact ESD per IEC 61000-4-2
● High-Speed Data Rates up to 20Mbps
● Up to -40°C to +125°C Operating Temperature
● Allows Up to 128 Transceivers on the Bus
Applications
● Industrial-Control Local Area Networks
● Transceivers for EMI-Sensitive Applications
● Telecommuncations
Ordering Information appears at end of data sheet.
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Absolute Maximum Ratings
(Voltages referenced to GND.)
VCC ......................................................................-0.3V to +4.0V
RO............................................................. -0.3V to (VCC + 0.3V)
RE, DE, DI.............................................................-0.3V to +4.0V
A, B, Y, Z.............................................................-9.0V to +13.0V
Short-Circuit Duration (RO, A, B, Y, Z) to GND..........Continuous
Operating Temperature Range
MAX3483AE/85AE/88AE/90AE/91AE........... -40°C to +125°C
MAX3488AE/90AE........................................ -40°C to +105°C
Junction Temperature.......................................................+150°C
Storage Temperature Range............................. -65°C to +150°C
Continuous Power Dissipation (TA = +70°C)
8 SO (derate at 7.6mW/°C above +70°C)....................606mW
14 SO (derate at 11.9mW/°C above +70°C)................952mW
Lead Temperature (soldering, 10s).................................. +300°C
Soldering Temperature (reflow)....................................... +260°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.
Package Thermal Characteristics (Note 1)
Junction-to-Case Thermal Resistance (θJC)
8-pin SO.......................................................................38°C/W
14-pin SO.....................................................................34°C/W
Junction-to-Ambient Thermal Resistance (θJA)
8-pin SO.....................................................................132°C/W
14-pin SO.....................................................................84°C/W
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Electrical Characteristics
(VCC = +3.0V to +3.6V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +3.3V and TA = +25°C.) (Notes 2, 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
3.6
V
POWER SUPPLY
Supply Voltage
Supply Current
Shutdown Supply Current
3.0
VCC
ICC
ISHDN
DE = VCC, RE = GND, no load
DE = 0, RE = 0, no load, DI = 0 or VCC
1.9
1.2
4
4.0
DE = GND, RE = VCC, MAX3483AE/85AE/91AE
10
mA
µA
DRIVER
Differential Driver Output
VOD
Change in Magnitude of Differential
Output Voltage
∆VOD
Driver Common-Mode Output Voltage
VOC
Change in Magnitude of CommonMode Voltage
ΔVOC
VCC = 3V, RL = 100Ω, Figure 1
2.0
VCC = 3V, RL = 54Ω, Figure 1
1.5
RL = 54Ω or 100Ω, Figure 1 (Note 4)
-0.2
RL = 54Ω or 100Ω, Figure 1
-0.2
2.2
VOH
A or B output, IA or B = -20mA
Single-Ended Driver Output Low
VOL
A or B output, IA or B = 20mA
Driver Short-Circuit Output Current
IOSD
www.maximintegrated.com
VCC/2
RL = 54Ω or 100Ω, Figure 1 (Note 4)
Single-Ended Driver Output High
VOUT = -7V
VOUT = +12V
V
+0.2
V
3
V
+0.2
V
V
0.8
-250
V
mA
250
mA
Maxim Integrated │ 2
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Electrical Characteristics (continued)
(VCC = +3.0V to +3.6V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +3.3V and TA = +25°C.) (Notes 2, 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
430
1000
UNITS
RECEIVER
Input Current
IA, B
DE = GND, VCC = GND VIN = +12V
or +3.6V
VIN = -7V
Differential Input Capacitance
CA, B
Between A and B, DE = GND, f = 4MHz
Receiver Differential Threshold Voltage
VTH
-7V ≤ VCM ≤ +12V
Receiver Input Hysteresis
ΔVTH
Receiver Input Resistance
RIN
-7V ≤ VCM ≤ +12V
Input Voltage High
VIH
DE, DI, RE
Input Voltage Low
VIL
DE, DI, RE
VHYS
DE, DI, RE
IIN
DE, DI, RE
Input Current
Input Impedance on First Transition
-300
12
-200
VCM = 0V
LOGIC INTERFACE (DI, DE, RE, RO)
Input Hysteresis
-450
-105
pF
-10
10
MAX3483AE/85AE
12
MAX3488AE/90AE/91AE
48
DE, RE
µA
mV
mV
kΩ
2.0
V
0.8
50
1
V
mV
±2
µA
10
kΩ
RO Output Voltage High
VOHRO
RE = GND, IRO = -2mA,
(VA - VB) > 200mV
RO Output Voltage Low
VOLRO
RE = GND, IRO = 2mA,
(VA - VB) < -200mV
0.4
V
RE = VCC, 0 ≤ VRO ≤ VCC
±1
µA
Receiver Three-State Output
Current
IOZR
RE Pulldown and DE Pullup
Resistance
RIN
Receiver Output Short-Circuit
Current
IOSR
VCC - 1.5
V
1
0 ≤ VRO ≤ VCC
MΩ
±110
mA
PROTECTION
Thermal Shutdown Threshold
TSHDN
Temperature rising
+160
°C
15
°C
IEC 61000-4-2 Air Gap Discharge to GND
±15
IEC 61000-4-2 Contact Discharge to GND
±8
Human Body Model to GND
±20
Human Body Model
±2
Thermal Shutdown Hysteresis
ESD Protection on A, B, Z, and Y
Pins
ESD Protection, All Other Pins
www.maximintegrated.com
kV
kV
Maxim Integrated │ 3
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Switching Characteristics MAX3485AE/MAX3490AE/MAX3491AE
(VCC = +3V to +3.6V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +3.3V and TA = +25°C.) (Notes 2, 3, 5)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DRIVER
Driver Propagation Delay
tDPLH
tDPHL
30
RL = 54Ω, CL = 50pF,
Figures 2 and 3
30
ns
Driver Differential Output Rise or
Fall Time
tHL, tLH
RL = 54Ω, CL = 50pF,
Figures 2 and 3
7
ns
Differential Driver Output Skew
|tDPLH - tDPHL|
tDSKEW
RL = 54Ω, CL = 50pF,
Figures 2 and 3 (Note 6)
3
ns
Maximum Data Rate
DRMAX
20
Mbps
Driver Enable to Output High
tDZH
RL = 110Ω, CL = 50pF,
MAX3485AE, MAX3491AE
Figures 4 and 5 (Note 7)
Driver Enable to Output Low
tDZL
RL = 110Ω, CL = 50pF,
MAX3485AE, MAX3491AE
Figures 4 and 5 (Note 7)
40
ns
Driver Disable Time from Low
tDLZ
RL = 110Ω, CL = 50pF,
MAX3485AE, MAX3491AE
Figures 4 and 5
40
ns
Driver Disable Time from High
tDHZ
RL = 110Ω, CL = 50pF,
MAX3485AE, MAX3491AE
Figures 4 and 5
40
ns
RL = 110Ω, CL = 15pF, MAX3485AE,
Figures 4 and 5 (Note 7)
6
µs
100
µs
6
µs
800
ns
Driver Enable from Shutdown to
Output High
tDLZ(SHDN)
Driver Enable from Shutdown to
Output Low
tDHZ(SHDN)
Time to Shutdown
tSHDN
RL = 1kΩ, CL = 15pF,
MAX3491AE, Figure 8
RL = 110Ω, CL = 15pF, MAX3485AE
Figures 4 and 5 (Note 7)
(Note 8)
50
40
ns
RECEIVER
Receiver Propagation Delay
tRPLH
tRPHL
Receiver Output Skew
tRSKEW
Maximum Data Rate
DRMAX
35
CL = 15pF, Figures 6 and 7
35
CL = 15pF, Figures 6 and 7
(Note 6)
2
20
ns
ns
Mbps
Receiver Enable to Output High
tRZH
RL = 1kΩ, CL = 15pF, MAX3485AE,
MAX3491AE, Figure 8 (Note 7)
40
ns
Receiver Enable to Output Low
tRZL
RL = 1kΩ, CL = 15pF, MAX3485AE,
MAX3491AE, Figure 8 (Note 7)
40
ns
Receiver Disable Time from Low
tRLZ
RL = 1kΩ, CL = 15pF, MAX3485AE,
MAX3491AE, Figure 8
40
ns
www.maximintegrated.com
Maxim Integrated │ 4
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Switching Characteristics MAX3485AE/MAX3490AE/MAX3491AE (continued)
(VCC = +3V to +3.6V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +3.3V and TA = +25°C.) (Notes 2, 3, 5)
PARAMETER
Receiver Disable Time from High
SYMBOL
CONDITIONS
tRHZ
RL = 1kΩ, CL = 15pF, MAX3485AE,
MAX3491AE, Figure 8
Receiver Enable from Shutdown to
Output High
tRLZ(SHDN)
Receiver Enable from Shutdown to
Output Low
tRHZ(SHDN)
Time to Shutdown
tSHDN
MIN
TYP
RL = 1kΩ, CL = 15pF,
MAX3485AE, Figure 8 (Note 7)
RL = 1kΩ, CL = 15pF,
MAX3491AE, Figure 8
RL = 1kΩ, CL = 15pF,
MAX3485AE, Figure 8 (Note 7)
RL = 1kΩ, CL = 15pF,
MAX3491AE, Figure 8
(Note 8)
50
MAX
UNITS
40
ns
6
µs
100
µs
6
µs
100
µs
800
ns
Switching Characteristics (MAX3483AE/MAX3488AE)
(VCC = +3V to +3.6V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +3.3V and TA = +25°C.) (Notes 2, 3, 5)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DRIVER
Driver Propagation Delay
tDPLH
tDPHL
1000
RL = 54Ω, CL = 50pF,
Figures 2 and 3
Driver Differential Output Rise or
Fall Time
tHL, tLH
RL = 54Ω, CL = 50pF,
Figures 2 and 3
Differential Driver Output Skew
|tDPLH - tDPHL|
tDSKEW
RL = 54Ω, CL = 50pF,
Figures 2 and 3
Maximum Data Rate
DRMAX
1000
200
ns
900
ns
140
ns
250
kbps
Driver Enable to Output High
tDZH
RL = 110Ω, CL = 50pF,
MAX3483AE
Figures 4 and 5 (Note 6)
2500
ns
Driver Enable to Output Low
tDZL
RL = 110Ω, CL = 50pF,
MAX3483AE
Figures 4 and 5 (Note 6)
2500
ns
Driver Disable Time from Low
tDLZ
RL = 110Ω, CL = 50pF,
MAX3483AE
Figures 4 and 5
100
ns
Driver Disable Time from High
tDHZ
RL = 110Ω, CL = 50pF,
MAX3483AE
Figures 4 and 5
100
ns
RL = 110Ω, CL = 15pF,
MAX3483AE
Figures 4 and 5 (Note 6)
10
µs
Driver Enable from Shutdown to
Output High
www.maximintegrated.com
tDLZ(SHDN)
Maxim Integrated │ 5
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Switching Characteristics (MAX3483AE/MAX3488AE) (continued)
(VCC = +3V to +3.6V, TA = TMIN to TMAX, unless otherwise specified. Typical values are at VCC = +3.3V and TA = +25°C.) (Notes 2, 3, 5)
PARAMETER
Driver Enable from Shutdown to
Output Low
Time to Shutdown
SYMBOL
CONDITIONS
tDHZ(SHDN)
RL = 110Ω, CL = 15pF, MAX3483AE
Figures 4 and 5 (Note 6)
tSHDN
(Note 8) MAX3483AE
MIN
50
TYP
340
MAX
UNITS
5.5
µs
700
ns
RECEIVER
Receiver Propagation Delay
tRPLH
tRPHL
Receiver Output Skew
tRSKEW
Maximum Data Rate
DRMAX
200
CL = 15pF, Figures 6 and 7
200
CL = 15pF, Figures 6 and 7
(Note 6)
30
250
ns
ns
kbps
Receiver Enable to Output High
tRZH
RL = 1kΩ, CL = 15pF,
MAX3483AE
Figure 8 (Note 6)
50
ns
Receiver Enable to Output Low
tRZL
RL = 1kΩ, CL = 15pF,
MAX3483AE
Figure 8 (Note 6)
50
ns
Receiver Disable Time from Low
tRLZ
RL = 1kΩ, CL = 15pF,
MAX3483AE
Figure 8
50
ns
Receiver Disable Time from High
tRHZ
RL = 1kΩ, CL = 15pF,
MAX3483AE
Figure 8
50
ns
Receiver Enable from Shutdown to
Output High
tRLZ(SHDN)
RL = 1kΩ, CL = 15pF,
MAX3483AE
Figure 8 (Note 6)
10
µs
Receiver Enable from Shutdown to
Output Low
tRHZ(SHDN)
RL = 1kΩ, CL = 15pF,
MAX3483AE
Figure 8 (Note 6)
10
µs
tSHDN
(Note 8) MAX3483AE
800
ns
Time to Shutdown
50
340
Note 2: All devices 100% production tested at TA = +25°C. Specifications over temperature are guaranteed by design.
Note 3: All currents into the device are positive; all currents out of the device are negative. All voltages are referenced to ground,
unless otherwise noted.
Note 4: ΔVOD and ΔVOC are the changes in VOD and VOC, respectively, when the DI input changes state.
Note 5: Capacitive load includes test probe and fixture capacitance.
Note 6: Guaranteed by design; not production tested.
Note 7: The timing parameter refers to the driver or receiver enable delay, when the device has exited the initial hot-swap protect
state and is in normal operating mode.
Note 8: Shutdown is enabled by driving RE high and DE low. The device is guaranteed to have entered shutdown after tSHDN has
elapsed.
www.maximintegrated.com
Maxim Integrated │ 6
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Test and Timing Diagrams
A
VCC
DE
RL
2
DI
A
VOD
B
VOD
RL
2
RL
CL
VOC
B
Figure 1. Driver DC Test Load
Figure 2. Driver Timing Test Circuit
tLH = 3ns, tHL = 3ns
VCC
DI
1.5V
1.5V
0
tDPHL
tDPLH
B
A
VOD
VOD = [VA - VB]
VO
VOD
90%
0
-VO
90%
10%
10%
tLH
tHL
tDSKEW = |tDPLH - tDPHL|
Figure 3. Driver Propagation Delays
www.maximintegrated.com
Maxim Integrated │ 7
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
GND OR VCC DI D
A
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
S1
B
VCC
OUT
CL
RL = 110Ω
DE
1.5V
tDZH, tDZH(SHDN)
DE
GENERATOR
0
0.25V
OUT
50Ω
VOH
1.5V
0
tDHZ
Figure 4. Driver Enable and Disable Times (tDZH, tDHZ)
VCC
0 OR VCC DI D
A
B
RL = 110Ω
S1
VCC
OUT
CL
VCC
OUT
DE
GENERATOR
DE
50Ω
1.5V
tDZL, tDZL(SHDN)
0
tDLZ
1.5V
VOL
0.25V
Figure 5. Driver Enable and Disable Times (tDZL, tDLZ)
A
ATE
R
VID
RO
B
Figure 6. Receiver Propagation Delay Test Circuit
www.maximintegrated.com
Maxim Integrated │ 8
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
A
1V
B
-1V
tRPHL
VOH
RO
tRPLH
1.5V
1.5V
VOL
tRSKEW = |tRPHL - tRPLH|
Figure 7. Receiver Propagation Delays
+1.5V
S3
-1.5V
VID
R
RO
RE
GENERATOR
1.5V
tRZH, tRZH(SHDN)
RO
0
S1 OPEN
S2 CLOSED
S3 = +1.5V
VCC
1.5V
tRHZ
RO
0.25V
VCC
S2
CL
15pF
VCC
1.5V
RE
0
S1 CLOSED
S2 OPEN
S3 = -1.5V
tRZL, tRZL(SHDN)
VOH
VCC
2
0
RE
S1
50Ω
VCC
RE
R
1kΩ
0
VCC
2
VOL
RO
VCC
S1 OPEN
S2 CLOSED
S3 = +1.5V
1.5V
RE
tRLZ
0
S1 CLOSED
S2 OPEN
S3 = -1.5V
VCC
VOH
0
VCC
RO
0.25V
VOL
Figure 8. Receiver Enable and Disable Times
www.maximintegrated.com
Maxim Integrated │ 9
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Typical Operating Characteristics
(VCC = +3.3V, TA = +25°C, unless otherwise specified.)
DE = VCC
RE = GND
30
MAX3483AE
2
1.5
MAX3488AE/90AE/91AE
MAX3485AE
1
0
MAX3488AE/90AE/91AE
15
0.5
MAX3483AE
MAX3485AE
5
-40 -25 -10 5
0
20 35 50 65 80 95 110 125
-40 -25 -10 5
TEMPERATURE (°C)
TOC04
60
DE = VCC
RE = GND
TOC05
MAX3483AE/85AE
2.0
MAX3485AE, NO LOAD
1.5
20
MAX3488AE/90AE/91AE
1.0
10
10
15
20
DATA RATE (Mbps)
0.0
0
10
20
30
40
200
250
TOC06
4
MAX3488AE/90AE/91AE
3
2
MAX3483AE/85AE
1
0
0
10
20
30
40
50
60
OUTPUT CURRENT (mA)
DIFFERENTIAL DRIVER OUTPUT VOLTAGE
vs. TEMPERATURE
TOC07
380
4.5
MAX3483AE/88AE - 250Kbps
DRIVER PROPAGATION DELAY
vs. TEMPERATURE
TOC8
375
4
3.5
MAX3488AE/90AE91AE
3
2.5
2
1.5
MAX3483AE/85AE
1
370
365
tDPHL, MAX3488AE
tDPLH, MAX3488AE
360
355
350
tDPLH , MAX3483AE
tDPHL , MAX3483AE
345
0.5
0
150
OUTPUT SINKING CURRENT
OUTPUT CURRENT (mA)
PROPAGATION DELAY (ns)
DIFFERENTIAL DRIVER OUTPUT VOLTAGE (V)
5
100
0.5
MAX3490AE/91AE, NO LOAD
5
50
RECEIVER OUTPUT LOW VOLTAGE
vs. OUTPUT CURRENT
5
OUTPUT SOURCING CURRENT
2.5
MAX3490AE/91AE, 54Ω load
0
0
3.5
40
0
MAX3488AE, NO LOAD
MAX3483AE NO LOAD
DATA RATE (kbps)
3.0
30
20
0
20 35 50 65 80 95 110 125
VOH (V)
SUPPLY CURRENT (mA)
50
MAX3488AE, 54Ω LOAD
30
10
RECEIVER OUTPUT HIGH
VOLTAGE vs. OUTPUT CURRENT
4.0
MAX3485AE, 54Ω LOAD
MAX3483AE, 54Ω LOAD
40
TEMPERATURE (°C)
MAX3485AE/90AE/91AE – 20Mbps
SUPPLY CURRENT vs. DATA RATE
DE = VCC
50
20
10
MAX3483AE/88AE - 250Kbps
SUPPLY CURRENT vs. DATA RATE TOC03
60
DE = GND
RE = VCC
25
SUPPLY CURENT (mA)
SUPPLY CURENT (mA)
2.5
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
TOC02
OUTPUT LOW VOLTAGE (V)
3
TOC01
SUPPLY CURENT (mA)
NO LOAD SUPPLY CURRENT
vs. TEMPERATURE
-40 -25 -10 5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
www.maximintegrated.com
340
RL = 54Ω
CL = 50pF
-40 -25 -10 5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Maxim Integrated │ 10
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Typical Operating Characteristics (continued)
(VCC = +3.3V, TA = +25°C, unless otherwise specified.)
tDPHL, MAX3490AE/91AE
14
tDPLH, MAX3485AE
RL = 54Ω
CL = 50pF
tDPHL, MAX3485AE
10
-40 -25 -10 5
12
10
8
6
MAX3483AE
4
2
0
TOC12
tLH, MAX3488AE
tLH, MAX3483AE
tHL, MAX3488AE
100
RL = 54Ω
CL = 50pF
50
-40 -25 -10 5
DRIVER OUTPUT RISE/FALL TIME (ns)
DIFFERENTIAL OUTPUT RISE/FALL TIME (ns)
250
150
5
4
6
2
-40 -25 -10 5
4
3
1
0
20 35 50 65 80 95 110 125
tLH, MAX3485A
5
2
tLH, MAX3490AE/91AE
RL = 54Ω
tHL, MAX3490AE/91AE
CL = 50pF
-40 -25 -10 5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
DRIVER OUTPUT TRANSITION SKEW (ns)
4
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
MAX3485AE/90AE/91AE
DRIVER OUTPUT RISE/FALL TIME
vs. TEMPERATURE
TOC13
tHL, MAX3485AE
MAX3490AE/91AE
MAX3485AE
3
20 35 50 65 80 95 110 125
7
300
0
8
tHL, MAX3483AE
350
200
6
TEMPERATURE (°C)
MAX3483AE/88AE
DRIVER OUTPUT RISE AND FALL TIME
vs. TEMPERATURE
TOC11
RL = 54Ω
CL = 50pF
7
0
-40 -25 -10 5
TEMPERATURE (°C)
400
8
MAX3485AE/90AE/91AE
DIFFERENTIAL DRIVER SKEW
vs. TEMPERATURE
1
MAX3488AE
-2
-4
10
9
14
20 35 50 65 80 95 110 125
450
TOC10
RL = 54Ω
CL = 50pF
60
DRIVER OUTPUT TRANSITION SKEW (ns)
12
16
MAX3483AE/88AE – 250Kbps
DIFFERENTIAL DRIVER SKEW
vs. TEMPERATURE
DIFFERENTIAL DRIVER SKEW (ns)
18
18
16
20
tDPLH, MAX3490AE/91AE
20
PROPAGATION DELAY (ns)
TOC9
DIFFERENTIAL DRIVER SKEW (ns)
22
MAX3485AE/90AE/91AE - 20Mbps
DRIVER PROPOGATION DELAY
vs. TEMPERATURE
MAX3483AE/88AE
DRIVER OUTPUT TRANSITION SKEW
vs. TEMPERATURE
TOC14
RL = 54Ω
CL = 50pF
55
50
45
40
35
30
MAX3488AE
25
20
MAX3483AE
15
10
5
0
-40 -25 -10 5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
MAX3485AE/90AE/91AE
DRIVER OUTPUT TRANSITION SKEW
vs. TEMPERATURE
TOC15
RL = 54Ω
CL = 50pF
3.5
3
2.5
2
MAX3485AE
1.5
MAX3490AE/91AE
1
0.5
0
-40 -25 -10 5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
www.maximintegrated.com
Maxim Integrated │ 11
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Pin Configuration
TOP VIEW
RO
1
RE
2
DE
3
DI
+
MAX3483AE
MAX3485AE
4
8
VCC
7
B
6
A
5
GND
+
N.C.
1
14 V CC
RO
2
13 N.C.
RE
3
12 A
DE
4
DI
5
10 Z
GND
6
9
Y
GND
7
8
N.C.
MAX3491AE
SO
11 B
VCC
1
RO
2
DI
GND
+
8
A
7
B
3
6
Z
4
5
Y
MAX3488AE
MAX3490AE
SO
SO
Pin Description
PIN
NAME
FUNCTION
MAX3483AE
MAX3485AE
MAX3488AE
MAX3490AE
MAX3491AE
—
—
1, 8, 13
N.C.
No Connection. Not internally connected.
1
2
2
RO
Receiver Output. Drive RE low to enable RO. RO is always active on the
MAX3488AE and MAX3490AE. RO is high when the receiver inputs (VA VB) > -10mV and low when (VA -VB) ≤200mV. See the Function Tables.
2
—
3
RE
Receiver Output Enable. Drive RE low, or leave unconnected, to enable
RO. RO is high impedance when RE is high. Drive RE high and DE low to
enter low-power shutdown mode. RE has a weak pulldown to GND.
DE
Driver Enable. Drive DE high, or leave unconnected, to enable the driver
outputs (Y and Z for full duplex, A and B for half duplex). The driver
outputs are high impedance when DE is low. Drive RE high and DE low to
enter low-power shutdown mode. DE has a weak pullup to VCC.
Driver Input. A low on DI forces the noninverting output (Y or A) low
and the inverting output (Z or B) high. Similarly, a high on DI forces the
noninverting output (Y or A) high and the inverting output (Z or B) low.
See the Function Tables.
3
—
4
4
3
5
DI
5
4
6, 7
GND
—
5
9
Y
Noninverting Driver Output
—
6
10
Z
Inverting Driver Output
7
7
11
B
Inverting Receiver Input/Driver Output (MAX3483AE/MAX3485AE).
Inverting Receiver Input (MAX3488AE/MAX3490AE/MAX3491AE).
6
8
12
A
Noninverting Receiver Input/Driver Output (MAX3483AE/MAX3485AE).
Noninverting Receiver Input (MAX3488AE/MAx3490AE/MAX3491AE).
8
1
14
VCC
Positive Supply. Bypass VCC to GND with a 0.1µF capacitor as close as
possible to the IC.
www.maximintegrated.com
Ground
Maxim Integrated │ 12
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Function Tables (MAX3483AE, MAX3485AE)
TRANSMITTING
INPUTS
RE
OUTPUTS
MODE
DE
DI
B
A
X
1
1
0
1
Active
X
1
0
1
0
Active
0
0
X
High Impedance
Driver Disabled
1
0
X
High Impedance
Shutdown
RECEIVING
INPUTS
RE
OUTPUTS
MODE
DE
A-B
RO
0
X
≥ -10mV
1
Active
0
X
≤ -200mV
0
Active
0
X
Open/Shorted
1
Active
1
1
X
High Impedance
Receiver Disabled
1
0
X
High Impedance
Shutdown
X = Don’t care
Function Tables MAX3491AE
TRANSMITTING
INPUTS
RE*
OUTPUTS
DE*
DI
Y
Z
X
1
1
1
0
X
1
0
0
1
0
0
X
High-Impedance
1
0
X
Shutdown
RECEIVING
RE*
INPUTs
OUTPUT
DE*
VA - VB
RO
0
X
≥ -10mV
1
0
X
≤ -200mV
0
0
X
Open/Shorted
1
1
1
X
High-Impedance
1
0
X
Shutdown
*RE and DE on the MAX3488AE and MAX3490AE are internal. The driver outputs and receiver are always active in these devices.
www.maximintegrated.com
Maxim Integrated │ 13
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Detailed Description
Hot-Swap Capability
The device features fail-safe receiver inputs guaranteeing a
logic-high receiver output when inputs are shorted or open.
The MAX3483AE/85AE has a 1-unit load receiver input
impedance, allowing up to 32 transceivers on the bus. The
MAX3488AE/90AE/91AE has a 1/4-unit load receiver input
impedance, allowing up to 128 transceivers on the bus.
When circuit boards are inserted in a hot or powered
backplane, disturbances on the enable inputs and differential
receiver inputs can lead to data errors. Upon initial circuit
board insertion, the processor undergoes its power-up
sequence. During this period, the processor output drivers are
high impedance and are unable to drive the DE and RE
inputs MAX3483AE/85AE/91AE to a defined logic level.
Leakage currents up to 10µA from the high-impedance
outputs of a controller could cause DE and RE to drift
to an incorrect logic state. Additionally, parasitic circuit
board capacitance could cause coupling of VCC or GND
to DE and RE. These factors could improperly enable the
driver or receiver. The integrated hot-swap inputs help to
avoid these potential problems.
The MAX3483AE/85AE and MAX3488AE/90AE/91AE
family are 3.3V ESD-protected RS-485/RS-422 transceivers
intended for half-duplex or full-duplex communications.
Integrated hot-swap functionality eliminates false transitions
on the bus during power-up or hot insertion.
True Fail Safe
The transceiver family guarantee 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. If the differential receiver
input voltage (A–B) is greater than or equal to -10mV, RO
is logic-high.
Driver Single-Ended Operation
The driver outputs can either be used in the standard
differential operating mode, or can be used as single-ended
outputs. Since the driver outputs swing rail-to-rail, they
can individually be used as standard TTL logic outputs.
For half-duplex transceivers, driver outputs are A and B.
For full-duplex transceivers, driver outputs are Y and Z.
Hot-Swap Inputs
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 hotswap-tolerable inputs.
Hot-Swap Input Circuitry
The DE and RE enable inputs feature hot-swap capability.
At the input, there are two nMOS devices, M1 and M2
(Figure 9). When VCC ramps from 0V, an internal 10µs
timer turns on M2 and sets the SR latch that also turns
on M1. Transistors M2 (a 500µA current sink) and M1 (a
100µA current sink) pull DE to GND through a 5kΩ (typ)
VCC
10µs
TIMER
TIMER
DE
DRIVER
ENABLE
(HOT SWAP)
5kΩ (typ)
100µA
M1
500µA
M2
Figure 9. Simplified Structure of the Driver Enable (DE) Pin
www.maximintegrated.com
Maxim Integrated │ 14
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
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 VCC drops below 1V, the hotswap input is reset.
A complementary circuit employing two pMOS devices
pulls RE to VCC.
±20kV ESD Protection
ESD protection structures are incorporated on all pins
to protect against electrostatic discharges encountered
during handling and assembly. The driver outputs and
receiver inputs have extra protection against static
electricity. The ESD structures withstand high ESD in all
states: normal operation, shutdown, and powered down.
After an ESD event, the transceiver family keeps working
without latch-up or damage.
ESD protection can be tested in various ways. The transmitter
outputs and receiver inputs are characterized for protection to
the following limits:
RC
1MΩ
CHARGE CURRENTLIMIT RESISTOR
HIGHVOLTAGE
DC
SOURCE
CS
100pF
RD
1.5kΩ
Figure 10. Human Body ESD Test Model
www.maximintegrated.com
● ±15kV using the Air-Gap Discharge method specified
in IEC 61000-4-2.
● ±8kV using the Contact Discharge method specified in
IEC 61000-4-2.
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 (HBM)
Figure 10 shows the HBM, and Figure 11 shows the current
waveform it generates when discharged into a lowimpedance state. 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 61000-4-2
The IEC 61000-4-2 standard covers ESD testing and
performance of finished equipment. However, it does not
specifically refer to integrated circuits. The transceiver
family helps in designing equipment to meet IEC 61000-4-2
without the need for additional ESD protection components.
The major difference between tests done using the HBM
and IEC 61000-4-2 is higher peak current in IEC 61000-4-2
because series resistance is lower in the IEC 61000-4-2 model.
Hence, the ESD withstand voltage measured to IEC 61000-4-2
is generally lower than that measured using the HBM.
IP 100%
90%
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
● ±20kV HBM using JEDEC JS-001-2014.
IR
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
AMPERES
DEVICE
UNDER
TEST
36.8%
10%
0
0
tRL
TIME
tDL
CURRENT WAVEFORM
Figure 11. Human Body Current Waveform
Maxim Integrated │ 15
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Figure 12 shows the IEC 61000-4-2 model, and Figure
13 shows the current waveform for IEC 61000-4-2 ESD
Contact Discharge test.
Applications Information
RE and DE can be connected together and driven simultaneously. The transceiver is 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 800ns (max), the
device is guaranteed to enter shutdown.
Driver Output Protection
Typical Applications
Two mechanisms prevent excessive output current and
power dissipation caused by faults or by bus connection.
The first, a current limit on the output stage provides
immediate protection against short circuits over the whole
common-mode voltage range. The second, a thermalshutdown circuit, forces the driver outputs into a highimpedance state if the die temperature exceeds +160°C (typ).
The transceiver family is designed for bidirectional data
communications on multipoint bus transmission lines.
Figure 14 and Figure 15 show typical network application
circuits. To minimize reflections, terminate the line at both
ends with its characteristic impedance and keep stub
lengths off the main line as short as possible.
Low-Power Shutdown Mode
(MAX3483AE, MAX3485AE,MAX3491AE)
Low-power shutdown mode is initiated by bringing RE
high and DE low. In shutdown, the devices draw less
than 10µA of supply current.
CHARGE CURRENTLIMIT RESISTOR
HIGHVOLTAGE
DC
SOURCE
CS
150pF
RD
330Ω
I
100%
90%
DISCHARGE
RESISTANCE
IPEAK
RC
50MΩ TO 100MΩ
DEVICE
UNDER
TEST
STORAGE
CAPACITOR
10%
tR = 0.7ns TO 1ns
t
30ns
60ns
Figure 12. IEC 61000-4-2 ESD Test Model
Figure 13. IEC 61000-4-2 ESD Generator Current Waveform
120Ω
DI
DE
B
B
D
D
DI
DE
RO
120Ω
A
B
A
B
A
A
R
R
RE
R
R
D
MAX3483AE/85AE
DI
RO
RE
D
DE
RO RE
DI
DE
RO RE
Figure 14. Typical Half-Duplex Application Circuit
www.maximintegrated.com
Maxim Integrated │ 16
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Y
A
RO
D
R
RE
DE
DI
B
Z
Z
B
DI
DE
RE
R
D
RO
A
Y
Y
Z
A
B
Y
Z
A
B
DI
DE
A
RO
DI
R
D
D
R
MAX3491AE
RE
RO
DI
DE
RE
RO
Y
R
D
B
Z
Z
B
D
R
Y
DI
RO
A
MAX3488AE
MAX3490AE
Figure 15. Typical Full-Duplex RS-485 Network
www.maximintegrated.com
Maxim Integrated │ 17
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Chip Information
Package Information
PROCESS: BiCMOS
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.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.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
8 SOIC
S8+2
21-0041
90-0096
8 SOIC
S8+4
21-0041
90-0096
14 SOIC
S14+1
21-0041
90-0112
Ordering Information
PART
DUPLEX
DATA RATE
(MAX)
PIN-PACKAGE
PACKAGE
CODE
TEMPERATURE
RANGE
NODES
32
MAX3483AEASA+
Half
0.25Mbps
8 SO
S8+2
-40°C to +125°C
MAX3485AEASA+
Half
20Mbps
8 SO
S8+2
-40°C to +125°C
32
MAX3488AEGSA+
Full
0.25Mbps
8 SO
S8+4
-40°C to +105°C
128
MAX3490AEGSA+
Full
20Mbps
8 SO
S8+4
-40°C to +105°C
128
MAX3491AEASD+
Full
20Mbps
14 SO
S14+1
-40°C to +125°C
128
+Denotes lead(Pb)-free/RoHS-compliant package.
www.maximintegrated.com
Maxim Integrated │ 18
MAX3483AE/MAX3485AE/
MAX3488AE/MAX3490AE/
MAX3491AE
+3.3V-Powered, ±20kV ESD-Protected,
20Mbps and Slew-Rate-Limited
RS-485/RS-422 Transceivers
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
0
3/16
Initial release
1
9/17
Updated General Description, Functional Diagram, Absolute Maximum
Ratings, Electrical Characteristics table, various figures, and Ordering
Information table
DESCRIPTION
—
1–6, 8, 10–12,
15–18
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated 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 and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2017 Maxim Integrated Products, Inc. │ 19
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