19-5254; Rev 1; 11/10
RS-485 Transceivers with Integrated
100
Ω
/120
Ω
Termination Resistors
General Description
The MAX13450E/MAX13451E are half-duplex and full-
duplex RS-485/RS-422 transceivers. These devices fea-
ture internal 100I and 120I termination resistors. The
resistor values are pin selectable. A logic supply input
allows interfacing to logic levels down to +1.8V.
The MAX13450E/MAX13451E feature strong drivers
specified to drive low-impedance lines found when a
fully loaded bus, based on today’s 100I characteristic
impedance cable, is doubly terminated. Both devices
allow slew-rate limiting of the driver output to reduce EMI
and reflections for data rates up to 500kbps.
The MAX13451E has a FAULT alarm indication output to
signal to the system that an error condition exists in the
driver. The MAX13451E also features a logic inversion
function. The logic inversion allows phase reversal of the
A-B signals in case these are inadvertently connected
wrongly.
The MAX13450E/MAX13451E have 1/8-unit load receiver
input impedance, allowing up to 256 transceivers on the
bus. All driver outputs are protected to
Q30kV
ESD using
the Human Body Model (HBM).
The MAX13450E/MAX13451E are available in a 14-pin
TSSOP package and operate over the automotive -40NC
to +125NC temperature range.
Resistors
S
Driver Drives 100I Double Termination
S
20Mbps (max) Data Rate
S
Pin-Selectable Slew-Rate Limiting
S
Logic Supply Input Allows Interfacing Down to 1.8V
S
Driver Fault-Indication Output (MAX13451E)
S
Inverting of A, B Line Polarity (MAX13451E)
S
High-Impedance Driver Output/Receiver Input
Features
S
100I/120I Pin-Selectable Internal Termination
MAX13450E/MAX13451E
When V
CC
Supply is Removed
S
Hot-Swap Input Structure on DE,
RE,
and
TERM
S
Extended ESD Protection
±30kV Human Body Model
±15kV Air Gap Discharge per IEC 61000-4-2
±7kV Contact Discharge per IEC 61000-4-2
S
1/8-Unit Load Allows Up to 256 Transceivers on
the Bus
S
Thermal and Overcurrent Protected
S
Fail-Safe Receivers
S
+4.5V to +5.5V Supply Voltage Range
Applications
Industrial Control Systems
Portable Industrial Equipment
Motor Control
Security Networks
Medical Networks
Functional Diagram (MAX13451E)
V
L
V
CC
SRL
INV
DI
FAULT
DE
TERM
LOGIC
LOGIC-LEVEL
TRANSLATION
RE
A
B
D
MAX13451E
Ordering Information/
Selector Guide
PART
MAX13450EAUD+
MAX13451EAUD+
HALF/FULL
DUPLEX
Full
Half
PIN-PACKAGE
14 TSSOP-EP*
14 TSSOP-EP*
Note:
All devices are specified over the -40°C to +125°C
operating temperature range.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
RO
TERM100
GND
_______________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
RS-485 Transceivers with Integrated
100
Ω
/120
Ω
Termination Resistors
MAX13450E/MAX13451E
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
V
CC
, V
L
...................................................................-0.3V to +6V
DE,
RE,
DI, RO,
TERM,
TERM100, SRL ..... -0.3V to (V
L
+ 0.3V)
INV, FAULT ................................................. -0.3V to (V
L
+ 0.3V)
A, B, Z, Y ..................................................................-8V to +13V
A to B (High-Z State) ......................................................... +14V
B to A (High-Z State) ......................................................... +14V
Short-Circuit Duration (RO, Y, Z) to GND ................ Continuous
Continuous Power Dissipation (T
A
= +70NC)
TSSOP (derate 25.6mW/NC above +70NC)................2051mW
Operating Temperature Range ....................... -40NC to +125NC
Storage Temperature Range .......................... -65NC to +150NC
Junction Temperature ....................................................+150NC
Lead Temperature (soldering, 10s) ...............................+300NC
Soldering Temperature (reflow) ......................................+260NC
PACKAGE THERMAL CHARACTERISTICS (Note 1)
TSSOP
Junction-to-Ambient Thermal Resistance (q
JA
) ..........39°C/W
Junction-to-Case Thermal Resistance (q
JC
) .................3°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.maxim-ic.com/thermal-tutorial.
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.
ELECTRICAL CHARACTERISTICS
(V
CC
= +4.5V to +5.5V, V
L
= +1.62V to V
CC
, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V,
V
L
= +1.8V, and T
A
= +25NC.) (Note 2)
PARAMETER
Supply Voltage
Logic Supply Voltage
Supply Current
Logic Supply Current
SYMBOL
V
CC
V
L
I
CC
I
L
DE =
RE
= high,
TERM
= high, no load
DE =
RE
= low,
TERM
= low, no load
Current into V
L
, no load on RO, device not
switching, DE =
RE
= high
Current into V
CC
, DE = low,
RE
=
TERM
=
high
Current into V
CC
, DE = low,
RE
= high,
TERM
= low
R
DIFF
= 100I, Figure 1 (Note 3)
R
DIFF
= 46I, Figure 1 (Note 3)
R
DIFF
= 100I or 46I, Figure 1 (Note 3)
R
DIFF
= 100I or 46I, Figure 1 (Note 3)
R
DIFF
= 100I or 46I, Figure 1 (Note 3)
0V
P
V
OUT
P
+12V
-7V
P
V
OUT
P
0V
-250
V
CC
/2
2.0
1.5
CONDITIONS
MIN
4.5
1.62
1.8
TYP
MAX
5.5
V
CC
6
12
2
30
8
UNITS
V
V
mA
FA
FA
mA
Shutdown Current
I
SHDN
DRIVER
Differential Driver Output
Change in Magnitude of
Differential Output Voltage
Driver Common-Mode Output
Voltage
Change In Magnitude of
Common-Mode Voltage
Driver Short-Circuit Output
Current
V
OD
DV
OD
V
OC
DV
OC
I
OSD
V
CC
V
CC
0.2
3
0.2
+280
V
V
V
V
mA
2
______________________________________________________________________________________
RS-485 Transceivers with Integrated
100
Ω
/120
Ω
Termination Resistors
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +4.5V to +5.5V, V
L
= +1.62V to V
CC
, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V,
V
L
= +1.8V, and T
A
= +25NC.) (Note 2)
PARAMETER
Driver Short-Circuit Foldback
Output Current
RECEIVER
Input Current (A and B)
I
A, B
DE =
RE
= GND;
TERM
= V
L
; V
CC
= GND
or 5.5V
-7V
P
V
CM
P
+12V,
DE =
RE
= GND;
TERM
= V
L
; V
CC
= GND
V
A
+ V
B
= 0V
DI, DE,
RE, TERM,
SRL, TERM100, INV
DI, DE,
RE, TERM,
SRL, TERM100, INV
DI, DE,
RE, TERM,
TERM100, SRL, INV
I
OUT
= -1mA
I
OUT
= +1mA
0V
P
V
RO
P
V
L
0V
P
V
RO
P
V
L
Fault condition, I
OUT
= -1mA
Nonfault condition; I
OUT
= +1mA
-1
Q1
V
L
- 0.6
0.4
+0.01
-1
V
L
- 0.6
0.4
+1
Q80
2/3 x V
L
1/3 x V
L
+1
V
A
or V
B
= +12V
V
A
or V
B
= -7V
V
A
or V
B
= +12V
-100
-200
15
-50
125
FA
SYMBOL
I
OSDF
CONDITIONS
(V
CC
- 1V)
P
V
OUT
P
+12V
-7V
P
V
OUT
P
0V
MIN
+15
-15
TYP
MAX
UNITS
mA
MAX13450E/MAX13451E
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
LOGIC INTERFACE
Input High Voltage
Input Low Voltage
Input Current
Receiver Output High Voltage
Receiver Output Low Voltage
Three-State Output Current at
Receiver
Receiver Output Short-Circuit
Current
Fault Output High Voltage
(MAX13451E)
Fault Output Low Voltage
(MAX13451E)
TERMINATION RESISTOR
100I Termination Resistor
120I Termination Resistor
Single-Ended Input Capacitance
vs. GND
ESD PROTECTION
V
TH
DV
TH
V
IH
V
IL
I
IN
V
ROH
V
ROL
I
OZR
I
OSR
V
FAULTH
V
FAULTL
mV
mV
V
V
FA
V
V
FA
mA
V
V
R
100
R
120
C
IN
TERM
= low, TERM100 = high
TERM
= low, TERM100 = low
f = 1MHz (MAX13451E only)
85
101
100
120
40
115
139
I
I
pF
Human Body Model
ESD Protection (A, B, Y, Z)
ESD Protection (All Other Pins)
IEC 61000-4-2 Air Gap Discharge
IEC 61000-4-2 Contact Discharge
Human Body Model
Q30
Q15
Q7
Q2
kV
_______________________________________________________________________________________
3
RS-485 Transceivers with Integrated
100
Ω
/120
Ω
Termination Resistors
MAX13450E/MAX13451E
SWITCHING CHARACTERISTICS—SRL = HIGH
(V
CC
= +4.5V to +5.5V, V
L
= +1.62V to V
CC
, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V,
V
L
= +1.8V and T
A
= +25NC.) (Note 2)
PARAMETER
DRIVER
Driver Propagation Delay
Differential Driver Output Skew
|t
DPLH
- t
DPHL
|
Driver Differential Output Rise or
Fall Time
Maximum Data Rate
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Driver Disable Delay
Driver Enable Delay
RECEIVER
Receiver Propagation Delay
Receiver Output Skew
Maximum Data Rate
Receiver Enable to Output High
Receiver Enable to Output Low
Receiver Disable from High
Receiver Disable from Low
Receiver Enable from Shutdown
to Output High
Receiver Enable from Shutdown
to Output Low
TERMINATION RESISTOR
Turn-Off Time
Turn-On Time
t
RTZ
t
RTEN
Figure 10
Figure 10
120
1
Fs
Fs
t
RPLH
t
RPHL
t
RSKEW
DR
MAX
t
RZH
t
RZL
t
RHZ
t
RLZ
S2 closed, C
L
= 100pF, R
L
= 500I,
Figures 8 and 9
S1 closed, C
L
= 100pF, R
L
= 500I,
Figures 8 and 9
Figures 8 and 9
Figures 8 and 9
C
L
= 15pF, |V
ID
|
R
2.0V; t
LH
, t
HL
P
15ns,
Figures 6 and 7
C
L
= 15pF, Figures 6 and 7
500
50
50
50
50
5000
5000
200
200
30
ns
ns
kbps
ns
ns
ns
ns
ns
ns
t
DPLH
t
DPHL
t
DSKEW
t
HL
t
LH
DR
MAX
t
DZH(SHDN)
t
DZL(SHDN)
t
DLZ
, t
DHZ
t
DZL
, t
DZH
S2 closed, R
L
= 500I, C
L
= 100pF,
Figures 4 and 5
S1 closed, R
L
= 500I, C
L
= 100pF,
Figures 4 and 5
Figures 4 and 5
Figures 4 and 5
R
DIFF
= 54I, C
L
= 50pF, Figures 2 and 3
R
DIFF
= 54I, C
L
= 50pF, Figure 3
R
DIFF
= 54I, C
L
= 50pF, Figures 2 and 3
100
100
500
4500
5200
100
2500
800
800
100
600
600
ns
ns
ns
kbps
ns
ns
ns
ns
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
t
RZH(SHDN)
Figures 8 and 9
t
RZL(SHDN)
Figures 8 and 9
4
______________________________________________________________________________________
RS-485 Transceivers with Integrated
100
Ω
/120
Ω
Termination Resistors
SWITCHING CHARACTERISTICS—SRL = LOW
(V
CC
= +4.5V to +5.5V, V
L
= +1.62V to V
CC
, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V,
V
L
= +1.8V, and T
A
= +25NC.) (Note 2)
PARAMETER
DRIVER
Driver Propagation Delay
Differential Driver Output Skew
|t
DPLH
- t
DPHL
|
Driver Differential Output Rise or
Fall Time
Maximum Data Rate
Driver Enable from Shutdown to
Output High
Driver Enable from Shutdown to
Output Low
Driver Disable Delay
Driver Enable Delay
RECEIVER
Receiver Propagation Delay
Receiver Output Skew
Maximum Data Rate
Receiver Enable to Output High
Receiver Enable to Output Low
Receiver Disable Time from High
Receiver Disable Time from Low
Receiver Enable from Shutdown
to Output High
Receiver Enable from Shutdown
to Output Low
TERMINATION RESISTOR
Turn-Off Time
Turn-On Time
t
RTZ
t
RTEN
Figure 10
Figure 10
120
1
Fs
Fs
t
RPLH
t
RPHL
t
RSKEW
DR
MAX
t
RZH
t
RZL
t
RHZ
t
RLZ
S2 closed, C
L
= 100pF, R
L
= 500I,
Figures 8 and 9
S1 closed, C
L
= 100pF, R
L
= 500I,
Figures 8 and 9
Figures 8 and 9
Figures 8 and 9
C
L
= 15pF, |V
ID
|
R
2.0V; t
LH
, t
HL
P
15ns,
Figures 6 and 7
C
L
= 15pF, Figures 6 and 7
20
50
50
50
50
2000
2000
50
50
6
ns
ns
Mbps
ns
ns
ns
ns
ns
ns
t
DPLH
t
DPHL
t
DSKEW
t
HL
, t
LH
DR
MAX
t
DZH(SHDN)
t
DZL(SHDN)
t
DLZ
, t
DHZ
t
DZL
, t
DZH
S2 closed, R
L
= 500I, C
L
= 100pF,
Figures 4 and 5
S1 closed, R
L
= 500I, C
L
= 100pF,
Figures 4 and 5
Figures 4 and 5
Figures 4 and 5
R
DIFF
= 54I, C
L
= 50pF, Figures 2 and 3
R
DIFF
= 54I, C
L
= 50pF, Figure 3
R
DIFF
= 54I, C
L
= 50pF, Figures 2 and 3
20
2000
2000
100
100
50
50
6
15
ns
ns
ns
Mbps
ns
ns
ns
ns
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX13450E/MAX13451E
t
RZH(SHDN)
Figures 8 and 9
t
RZL(SHDN)
Figures 8 and 9
Note 2:
All devices are 100% production tested at T
A
= +25°C. Limits over temperature are guaranteed by design.
Note 3:
Termination resistance is disabled (TERM = high).
_______________________________________________________________________________________
5
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