EVALUATION KIT AVAILABLE
MAX14852/MAX14854
2.75kV
RMS
Isolated 500kbps/25Mbps Full-Duplex
RS-485/RS-422 Transceivers
with ±35kV ESD Protection
Benefits and Features
General Description
The MAX14852/MAX14854 isolated RS-485/RS-422
transceivers provide 2750V
RMS
(60s) of galvanic isola-
tion between the cable side (RS-485/RS-422 driver/
receiver side) and the UART side of the device. Isolation
improves communication by breaking ground loops and
reduces noise when there are large differences in ground
potential between ports. These devices allow for robust
communication up to 500kbps (MAX14852) or 25Mbps
(MAX14854).
The devices include one drive channel and one receive
channel. The receiver is 1/4-unit load, allowing up to 128
transceivers on a common bus.
Integrated true fail-safe circuitry ensures a logic-high on
the receiver output when inputs are shorted or open.
Undervoltage lockout disables the driver when cable side
or UART-side power supplies are below functional levels.
The driver outputs and receiver inputs are protected
from ±35kV electrostatic discharge (ESD) to GNDB on
the cable side, as specified by the Human Body Model
(HBM).
The MAX14852/MAX14854 are available in a wide-body
16-pin SOIC package and operate over the -40°C to
+105°C temperature range.
●
High-Performance Transceiver Enables Flexible Designs
• Integrated LDO for Cable Side Power
• Compliant with RS-485 EIA/TIA-485 Standard
• 500kbps (MAX14852)/25Mbps (MAX14854) Maximum
Data Rate
• Allows Up to 128 Devices on the Bus
●
Integrated Protection Ensures for Robust Communication
• ±35kV ESD (HBM) on Driver Outputs/Receiver Inputs
• 2.75kV
RMS
Withstand Isolation Voltage for 60
Seconds (V
ISO
)
• 630VPEAK Maximum Repetitive Peak-Isolation
Voltage (V
IORM
)
• 445VRMS Maximum Working-Isolation Voltage
(V
IOWM
)
• > 30 Years Lifetime at Rated Working Voltage
• Withstands ±10kV Surge per IEC 61000-4-5
• Thermal Shutdown
●
UL According to UL1577
●
cUL According to CSA Bulletin 5A
●
●
●
●
Safety Regulatory Approvals Pending
Applications
Industrial Automation Equipment
Programmable Logic Controllers
HVAC
Power Meters
Functional Diagram
VDDA
VLDO
Ordering Information
appears at end of data sheet.
MAX14852
MAX14854
LDO
SBA
RXD
RE
TXD
DE
VDDB
RS-485
TRANSCEIVER
A
B
Z
Y
GNDA
GNDB
19-7965; Rev 1; 1/17
MAX14852/MAX14854
2.75kV
RMS
Isolated 500kbps/25Mbps Full-Duplex
RS-485/RS-422 Transceivers
with ±35kV ESD Protection
Continuous Power Dissipation (T
A
= +70°C)
16-pin Wide SOIC
(derate 14.1mW/°C above +70°C) .......................... 1126.8mW
Operating Temperature Range ......................... -40°C to +105°C
Junction Temperature ......................................................+150°C
Storage Temperature Range ............................ -65°C to +150°C
Lead Temperature (soldering, 10s) ................................. +300°C
Soldering Temperature (reflow) ....................................... +260°C
Absolute Maximum Ratings
V
DDA
to GNDA .......................................................-0.3V to +6V
V
DDB
to GNDB ........................................................-0.3V to +6V
V
LDO
to GNDB ......................................................-0.3V to +16V
TXD, DE,
RE
to GNDA ...........................................-0.3V to +6V
SBA,
RXD to GNDA ............................. -0.3V to (VDDA + 0.3V)
A, B, Z, Y to GNDB ..................................................-8V to +13V
Short Circuit Duration (RXD,
SBA
to GNDA,
A, B, Y, Z ,V
DDB
to GNDB) ....................................Continuous
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-Ambient Thermal Resistance (θ
JA
) ..............71°C/W
Junction-to-Case Thermal Resistance (θ
JC
) ...................23°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.
DC Electrical Characteristics
(V
DDA
– V
GNDA
= 1.71V to 5.5V, V
DDB
– V
GNDB
= 3.0V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
V
DDA
– V
GNDA
= 3.3V, V
DDB
– V
GNDB
= 3.3V, V
GNDA
= V
GNDB
, and TA = +25°C.) (Notes 2, 3)
PARAMETER
POWER
Supply Voltage
V
DDA
V
DDB
I
DDA
I
DDB
Undervoltage Lockout Thresh-
old
Undervoltage Lockout Thresh-
old Hysteresis
LDO
LDO Supply Voltage
LDO Supply Current
LDO Output Voltage
LDO Current Limit
Load Regulation
Line Regulation
Dropout Voltage
VLDO = 3.3V, ILOAD = 20mA to 40mA
VLDO = 3.3V to 14V, ILOAD = 20mA
VLDO = 3.18V, IDDB = -120mA
VLDO
ILDO
VDDB
Relative to GNDB, LDO is on (Note 4)
DE = high, TXD = low, no bus load,
VLDO = 5.5V
3.0
3.18
7.5
3.3
300
0.19
0.12
100
1.7
1.8
180
14
12.9
3.6
V
mA
V
mA
mV/mA
mV/V
mV
V
UVLOA
V
UVLOB
V
UVHYSTA
V
UVHYSTB
VDDA = 5V, DE = high,
RE
= TXD = low,
RXD unconnected, no load
DE = high,
RE
= TXD = low, RXD uncon-
nected, no bus load, VDDB = 3.3V
VDDA rising
VDDB rising
1.50
2.55
1.71
3.0
3.9
7
1.58
2.7
50
200
5.5
5.5
6.6
mA
12.5
1.65
2.85
V
mV
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Current
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Maxim Integrated
│
2
MAX14852/MAX14854
2.75kV
RMS
Isolated 500kbps/25Mbps Full-Duplex
RS-485/RS-422 Transceivers
with ±35kV ESD Protection
DC Electrical Characteristics (continued)
(V
DDA
– V
GNDA
= 1.71V to 5.5V, V
DDB
– V
GNDB
= 3.0V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
V
DDA
– V
GNDA
= 3.3V, V
DDB
– V
GNDB
= 3.3V, V
GNDA
= V
GNDB
, and T
A
= +25°C.) (Notes 2, 3)
PARAMETER
Load Capacitance
SYMBOL
CONDITIONS
Nominal value (Note 7)
2.25V
≤
VDDA
≤
5.5V
1.71V
≤
VDDA
≤
1.89V
2.25V
≤
VDDA
≤
5.5V
1.71V
≤
VDDA
≤
1.89V
MIN
1
0.7 x
VDDA
0.78 x
VDDA
0.8
0.6
220
2
-10
1.5
3
RXD to GNDA, IOUT = -4mA
RXD to GNDA, IOUT = 4mA
SBA
to GNDA, IOUT = 4mA
0V ≤ V
RXD
≤ V
DDA, (VA - VB) > -10mV,
RE
= low
0V ≤ V
RXD
≤ V
DDA, (VA - VB) <
-200mV,
RE
= low
0V ≤ V
SBA
≤ V
DDA, side B is powered
and working
0V ≤ V
RXD
≤ V
DDA,
RE
= high
RL
= 54Ω, TXD = high or low, Figure 1a
Differential Driver Output
|VOD|
RL
= 100Ω, TXD = high or low, Figure 1a
-7V
≤
VCM
≤
+12V, Figure 1b
Change in Magnitude of Differ-
ential Driver Output Voltage
Driver Common-Mode Output
Voltage
Change in Magnitude of
Common-Mode Voltage
ΔV
OD
VOC
ΔV
OC
RL = 100Ω
or 54Ω, Figure 1a (Note 5)
RL = 100Ω
or 54Ω, Figure 1a (Note 5)
RL = 100Ω
or 54Ω, Figure 1a (Note 5)
VDDB/
2
-1
-42
40
mA
60
+1
µA
VDDA
-0.4
0.40
0.45
-4.5
4.5
5
-1.5
10
8
mV
pF
µA
µA
kΩ
V
V
mA
TYP
MAX
10
UNITS
µF
LOGIC INTERFACE (TXD, RXD, DE,
RE, SBA)
Input High Voltage
VIH
RE,
TXD, DE to
GNDA
V
Input Low Voltage
Input Hysteresis
Input Capacitance
Input Pullup Current
Input Pulldown Current
SBA
Pullup Resistance
Output Voltage High
Output Voltage Low
Short-Circuit Output Pullup
Current
Short-Circuit Output Pulldown
Current
VIL
VHYS
CIN
IPU
IPD
RSBA
VOH
VOL
ISH_PU
RE,
TXD, DE to
GNDA
V
RE,
TXD, DE to GNDA
RE,
TXD, DE, f = 1MHz
TXD
DE,
RE
ISH_PD
Three-State Output Current
DRIVER
IOZ
1.5
2.0
1.5
5
0.2
3
0.2
V
V
V
V
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Maxim Integrated
│
3
MAX14852/MAX14854
2.75kV
RMS
Isolated 500kbps/25Mbps Full-Duplex
RS-485/RS-422 Transceivers
with ±35kV ESD Protection
DC Electrical Characteristics (continued)
(V
DDA
– V
GNDA
= 1.71V to 5.5V, V
DDB
– V
GNDB
= 3.0V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
V
DDA
– V
GNDA
= 3.3V, V
DDB
– V
GNDB
= 3.3V, V
GNDA
= V
GNDB
, and T
A
= +25°C.) (Notes 2, 3)
PARAMETER
Driver Short-Circuit Output
Current
Single-Ended Driver Output
Voltage High
Single-Ended Driver Output
Voltage Low
Differential Driver Output
Capacitance
RECEIVER
Input Current (A and B)
Receiver Differential Threshold
Voltage
Receiver Input Hysteresis
Receiver Input Resistance
Differential Input Capacitance
PROTECTION
Thermal-Shutdown Threshold
Thermal-Shutdown Hysteresis
ESD Protection
(A and B Pins to GNDB)
ESD Protection (All Other Pins)
T
SHDN
T
HYST
Human Body Model
IEC 61000-4-2 Air Gap Discharge
IEC 61000-4-2 Contact Discharge
Human Body Model
Temperature Rising
+160
15
±35
±18
±8
±4
kV
kV
°C
°C
IA, IB
VTH
ΔV
TH
RIN
CA,B
DE = low, VDDB
= GNDB or 3.6V
-7V ≤ V
CM
≤ +12V
VCM = 0V
-7V ≤ V
CM
≤ +12V, DE = low
Measured between A and B, DE =
RE
=
low at 6MHz
48
12
VIN = +12V
VIN = -7V
+250
-200
-200
-120
20
-10
µA
mV
mV
kΩ
pF
SYMBOL
CONDITIONS
GNDB ≤ V
OUT
≤ +12V, output low (Note
6)
-7V ≤ V
OUT
≤ V
DDB, output high (Note
6)
Y and Z outputs, IY,Z = -20mA
Y and Z outputs, IY,Z = +20mA
DE =
RE
= high, f = 4MHz
12
MIN
+30
-250
2.2
0.8
TYP
MAX
+250
mA
-30
V
V
pF
UNITS
IOSD
VOH
VOL
COD
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Maxim Integrated
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4
MAX14852/MAX14854
2.75kV
RMS
Isolated 500kbps/25Mbps Full-Duplex
RS-485/RS-422 Transceivers
with ±35kV ESD Protection
Switching Electrical Characteristics (MAX14852)
(V
DDA
– V
GNDA
= 1.71V to 5.5V, V
DDB
– V
GNDB
= 3.0V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
V
DDA
– V
GNDA
= 3.3V, V
DDB
– V
GNDB
= 3.3V, V
GNDA
= V
GNDB
, and T
A
= +25°C.) (Note 7)
PARAMETER
DYNAMIC
Common Mode Transient
Immunity
Glitch Rejection
DRIVER
Driver Propagation Delay
Differential Driver Output Skew
|tDPLH - tDPHL|
Driver Differential Output 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
Receiver Propagation Delay
Receiver Output Skew
|tRPLH - tRPHL|
Maximum Data Rate
Receiver Enable to Output High
Receiver Enable to Output Low
Receiver Disable Time From Low
Receiver Disable Time From High
tRPLH, tRPHL
tRSKEW
DRMAX
tRZH
tRZL
tRLZ
tRHZ
CL = 15pF, Figure 6 and Figure 7
(Note 9)
CL = 15pF, Figure 6 and Figure 7
(Note 9)
500
RL
= 1kΩ, C
L = 15pF, S2 closed,
Figure 8
RL
= 1kΩ, C
L = 15pF, S1 closed,
Figure 8
RL
= 1kΩ, C
L = 15pF, S1 closed,
Figure 8
RL
= 1kΩ, C
L = 15pF, S2 closed,
Figure 8
20
30
20
20
240
34
ns
ns
kbps
ns
ns
ns
ns
tDPLH, tDPHL
tDSKEW
tLH, tHL
DRMAX
tDZH
tDZL
tDLZ
tDHZ
RL
= 110Ω, C
L = 50pF, Figure 5
RL
= 110Ω, C
L = 50pF, Figure 5
RL
= 110Ω, C
L = 50pF, Figure 5
RL
= 110Ω, C
L = 50pF, Figure 4
RL
= 54Ω, C
L = 50pF, Figure 2 and
Figure 3
RL
= 54Ω, C
L = 50pF, Figure 2 and
Figure 3
R
L
= 54Ω, C
L = 50pF, Figure 2 and
Figure 3
500
2540
2540
140
140
1040
144
900
ns
ns
ns
kbps
ns
ns
ns
ns
CMTI
(Note 8)
TXD, DE, RXD
10
35
17
29
kV/μs
ns
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
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Maxim Integrated
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