概述
规格参数
数据手册MAX14775EASA+ 概述
Line Transceiver, 线路驱动器或接收器
MAX14775EASA+ 规格参数
| 是否无铅： | 不含铅 | 是否Rohs认证： | 符合 |
| 生命周期： | Active | 包装说明： | , |
| Reach Compliance Code： | compliant | ECCN代码： | EAR99 |
| HTS代码： | 8542.39.00.01 | Factory Lead Time： | 13 weeks |
| 风险等级： | 2.29 | 接口集成电路类型： | LINE TRANSCEIVER |
| 峰值回流温度（摄氏度）： | NOT SPECIFIED | 处于峰值回流温度下的最长时间： | NOT SPECIFIED |
| Base Number Matches： | 1 |
MAX14775EASA+ 数据手册
通过下载MAX14775EASA+数据手册来全面了解它。这个PDF文档包含了所有必要的细节，如产品概述、功能特性、引脚定义、引脚排列图等信息。
PDF下载EVALUATION KIT AVAILABLE
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
General Description
Benefits and Features
● Integrated Protection Ensures for Robust
The MAX14775E/MAX14776E fault-protected RS-485/
RS-422 transceivers feature ±65V protection for overvoltage
signal faults on communication bus lines, ensuring
communication in harsh industrial environments.
Each device contains one driver and one receiver and
operates over the 3V to 5.5V supply range. The
MAX14775E is optimized for high-speed data rates up
to 20Mbps. The MAX14776E features slew-rate limited
outputs for data rates up to 500kbps.
Communication
•ꢀ ±65V Fault Protection Range on Driver Outputs/
Receiver Inputs
•ꢀ ±25V Common Mode Range on the Receiver Inputs
•ꢀ Large Receiver Hysteresis Increases Noise Tolerance
•ꢀ Hot-Swap Protection
•ꢀ Thermal Shutdown
● High-Performance Transceiver Enables Flexible
Designs
These transceivers are optimized for robust communication
in noisy environments. A large 200mV (typ) hysteresis on
receiver inputs ensure for high noise rejection and a fail-
safe feature guarantees a logic-high on the receiver output
when the inputs are open or shorted. Driver outputs are
protected against short-circuit conditions.
•ꢀ Compliant with RS-485 EIA/TIA-485 Standard
•ꢀ 20Mbps (MAX14775E)/500kbps (MAX14776E)
Maximum Data Rate
•ꢀ 3V to 5.5V Supply Range
•ꢀ Up to 100 Devices on the Bus
The MAX14775E/MAX14776E receivers feature a 1/3-
unit load input impedance, allowing up to 100 transceivers
on a bus.
Applications
● Industrial Field Bus Networks
● Motion Controllers
● HVAC
The MAX14775E/MAX14776E are available in 8-pin
SOIC and 8-pin TDFN-EP packages and operate over the
-40°C to +125°C temperature range.
Ordering Information appears at end of data sheet.
Selector Guide
PART NUMBER
MAX14775EASA+
MAX14775EATA+
MAX14776EASA+
MAX14776EATA+
MAX DATA RATE
PIN-PACKAGE
8 SOIC
20Mbps
20Mbps
500kbps
500kbps
8 TDFN-EP
8 SOIC
8TDFN-EP
19-8614; Rev 0; 9/16
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Absolute Maximum Ratings
(All voltages referenced to GND)
Continuous Power Dissipation (T = +70°C)
A
V
........................................................................-0.3V to +6V
8-pin SOIC (derate 7.60mW/°C above +70°C) ........606.1mW
8-pin TDFN (derate 24.4mW/°C above +70°C) ......1951.2mW
Operating Temperature Range......................... -40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range............................ -65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow).......................................+260°C
CC
RO ............................................................-0.3V to (V
+ 0.3V)
CC
DE, DI, RE...............................................................-0.3V to +6V
A, B (I = ±1mA) ..............................................-70V to +70V
MAX
Short-Circuit Duration (RO, A, B)..............................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.
(Note 1)
Package Thermal Characteristics
SOIC
TDFN
ꢀ
ꢀ
Junction-to-AmbientꢀThermalꢀResistanceꢀ(θ ).......132°C/W
ꢀ
ꢀ
Junction-to-AmbientꢀThermalꢀResistanceꢀ(θ ).........41°C/W
Junction-to-CaseꢀThermalꢀResistanceꢀ(θ ) ...............8°C/W
JC
JA
JA
Junction-to-CaseꢀThermalꢀResistanceꢀ(θ ) .............38°C/W
JC
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
= 3.0V to 5.5V, T = T
to T
, unless otherwise noted. Typical values are at V
= 3.3V and T = +25°C.) (Note 2)
A
CC
A
MIN
MAX
CC
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POWER
Supply Voltage
V
3.0
5.5
5.3
V
CC
DE = high, RE = low, no load, no
switching
Supply Current
I
3
4
mA
μA
μA
CC
Shutdown Supply Current
I
DE = high, RE = low
SH
Shutdown Short-Circuit Supply
Current
A or B shorted to ±65V, DE = high,
RE = low
I
240
SHDN_SHRT
DRIVER
R ꢀ=ꢀ54Ω,ꢀFigureꢀ1a
1.5
2.0
L
Differential Driver Output
|V
|
V
OD
R ꢀ=ꢀ100Ω,ꢀFigureꢀ1a
L
Change in Magnitude of Differ-
ential Driver Output Voltage
ΔV
R
= 100Ωꢀorꢀ54Ω,ꢀFigureꢀ1aꢀ(Noteꢀ3)
-0.2
+0.2
3
V
V
OD
L
Driver Common-Mode Output
Voltage
V
R ꢀ=ꢀ100Ωꢀorꢀ54Ω,ꢀFigureꢀ1a
L
V
CC
/ 2
OC
Change in Magnitude of
Common-Mode Voltage
ΔV
R ꢀ=ꢀ100Ωꢀorꢀ54Ω,ꢀFigureꢀ1aꢀ(Noteꢀ3)
-0.2
+0.2
V
V
OC
L
Single-Ended Driver Output
Voltage High
A and B outputs, output is high,
V
V
-0.2
CC
OH
I
= 3mA
SOURCE
A and B outputs, output is low,
= 3mA
Single-Ended Driver Output
Voltage Low
V
0.2
V
OL
I
SINK
Driver Short-Circuit Output
Current
-65Vꢀ≤ꢀV
V ꢀ≤ꢀ+65Vꢀ(Noteꢀ4)
B
V
< 0V or V
< V
CC A or
A or
B
I
200
mA
OSD1
Maxim Integrated
│ 2
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
DC Electrical Characteristics (continued)
(V
= 3.0V to 5.5V, T = T
to T
, unless otherwise noted. Typical values are at V
= 3.3V and T = +25°C.) (Note 2)
A
CC
A
MIN
MAX
CC
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Average Driver Short-Circuit
Output Current
I
0Vꢀ≤ꢀV
V ꢀ≤ꢀV
250
mA
OSD2
A or
B
CC
RECEIVER
V
V
= +12V
= -7V
+280
CM
CM
DE = low,
Input Current (A, B)
I , I
µA
A
B
0V ≤ꢀV
≤ꢀ5.5V
-200
38
CC
Receiver Input Resistance
R
IN
-7Vꢀ≤ꢀV
ꢀ≤ꢀ+12V
CM
kΩ
Common Mode Voltage Range
V
-25
+25
V
CM
Receiver Differential Threshold
Voltage Rising
V
-25Vꢀ≤ꢀV
-25Vꢀ≤ꢀV
ꢀ≤ꢀ+25V
ꢀ≤ꢀ+25V
+40
+200
mV
mV
THH
CM
Receiver Differential Threshold
Voltage Falling
V
-200
-40
THL
ΔV
CM
V
< t
= 0V, time from last transition
CM
Receiver Input Hysteresis
250
50
mV
TH
D_FS
25Vꢀ≤ꢀV
ꢀ≤ꢀ+25V,ꢀtimeꢀfromꢀlastꢀ
CM
Differential Input Fail-safe
Threshold
V
-40
+40
mV
pF
TH_FSH
transition > t
D_FS
Measured between A and B, f = 1MHz
Differential Input Capacitance
LOGIC OUTPUTS (RO)
C
V
A,B
RO Output Logic High Voltage
I
I
= 3mA, (V - V )ꢀ≥ꢀ+200mV
V
-0.4
CC
V
OH
SOURCE
A
B
RO Output Logic Low Voltage
RO Leakage Current
V
= 3mA, (V - V ) < +200mV
0.4
+1
V
OL
SINK
A
B
I
RE = high, 0V ≤ꢀV
≤ꢀV
CC
-1
μA
mA
OZR
RO
RO Short-Circuit Current
LOGIC INPUTS (DE, DI, RE)
I
0V ≤ꢀV
≤ꢀV
CC
70
OSR
RO
0.67 x
Input Logic High Voltage
V
V
V
IH
V
CC
0.33 x
Input Logic Low Voltage
V
IL
V
CC
Input Hysteresis
V
100
mV
HYS
Input Leakage Current
I
-1
1
+1
10
μA
IN
Input Impedance on First
Transition
R
DE, RE
kΩ
IN_FT
PROTECTION
Thermal-Shutdown Threshold
Thermal-Shutdown Hysteresis
T
Temperature rising
+162
12
°C
°C
SHDN
T
HYST
Human Body Model
±8
ESD Protection
(A, B Pins to GND)
kV
IEC 61000-4-2- Contact Discharge
Human Body Model
±5
±2
ESD Protection (All Other Pins)
kV
V
Fault Protection Range (A, B
Pins to GND)
-65
+65
Maxim Integrated
│ 3
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Switching Electrical Characteristics (MAX14775E)
(V
= 3.0V to 5.5V, T = T
to T
, unless otherwise noted. Typical values are at V
= 3.3V and T = +25°C.) (Note 2)
A
CC
A
MIN
MAX
CC
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DRIVER
R ꢀ=ꢀ54Ω,ꢀC = 50pF, Figure 2 and
Figure 3
L
L
Driver Propagation Delay
t
t
40
9
ns
ns
DPLH, DPHL
Differential Driver Output Skew
|t - t
R ꢀ=ꢀ54Ω,ꢀC = 50pF, Figure 2 and
L L
Figure 3 (Note 7)
t
DSKEW
|
DPLH DPHL
Driver Differential Output Rise
or Fall Time
R ꢀ=ꢀ54Ω,ꢀC = 50pF, Figure 2 and
Figure 3 (Note 7)
L
L
t
, t
LH HL
8
15
ns
Maximum Data Rate
DR
MAX
20
Mbps
ns
Driver Enable to Output High
Driver Enable to Output Low
t
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 4
90
90
DZH
L
L
t
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 5
ns
DZL
L
L
-20V ≤V
Figure 1a
≤+25V, 4.5V ≤V
≤5.5V,
CM
CC
Driver Enable Time
t
1000
ns
D
Driver Disable Time From Low
Driver Disable Time From High
t
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 5
50
50
ns
ns
DLZ
L
L
t
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 4
L L
DHZ
Driver Enable Time from
Shutdown to Output High
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 4
(Note 5)
L
L
t
170
μs
DLZ(SHDN)
Driver Enable Time from
Shutdown to Output Low
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 4
(Note 5)
L
L
t
170
800
μs
DHZ(SHDN)
Time to Shutdown
t
(Note 5)
50
ns
SHDN
RECEIVER (Note 6)
Receiver Propagation Delay
Receiver Output Skew
t
t
C
C
= 15pF, Figure 6 and Figure 7
= 15pF, Figure 6 and Figure 7
50
5
ns
ns
RPLH, RPHL
L
L
t
RSKEW
(Note 7)
Receiver Enable to Output
High
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S2 closed,
Figure 8
L
L
t
50
50
ns
ns
ns
ns
μs
μs
RZH
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S1 closed,
L
L
Receiver Enable to Output Low
t
RZL
RLZ
RHZ
Figure 8
Receiver Disable Time From
Low
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S1 closed,
L
L
t
50
Figure 8
Receiver Disable Time From
High
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S2 closed,
L
L
t
50
Figure 8
Receiver Enable from
Shutdown to Output Low
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S2 closed,
L L
Figure 8 (Note 5)
t
170
RLZ(SHDN)
Receiver Enable from
Shutdown to Output High
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S2 closed,
L
L
t
170
800
RHZ(SHDN)
Figure 8 (Note 5)
Time to Shutdown
t
(Note 5)
50
ns
SHDN
Delay to Fail-Safe Operation
t
10
μs
D_FS
Maxim Integrated
│ 4
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Switching Electrical Characteristics (MAX14776E)
(V
= 3.0V to 5.5V, T = T
to T
, unless otherwise noted. Typical values are at V
= 3.3V and T = +25°C.) (Note 2)
A
CC
A
MIN
MAX
CC
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DRIVER
R ꢀ=ꢀ54Ω,ꢀC = 50pF, Figure 2 and
Figure 3
L
L
Driver Propagation Delay
t
t
100
105
1000
ns
ns
DPLH, DPHL
Differential Driver Output Skew
|t - t
R ꢀ=ꢀ54Ω,ꢀC = 50pF, Figure 2 and
L L
Figure 3 (Note 7)
t
140
600
600
DSKEW
|
DPLH DPHL
3V ≤ꢀV
≤ꢀ3.6V
R ꢀ=ꢀ54Ω,ꢀC
50pF, Figure 2
and Figure 3
=
L
CC
L
Driver Differential Output Rise
or Fall Time
t
, t
LH HL
ns
4.5V ≤ꢀV
CC
≤ꢀ5.5V
105
500
Maximum Data Rate
DR
MAX
kbps
ns
Driver Enable to Output High
Driver Enable to Output Low
t
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 4
2500
2500
DZH
L
L
t
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 5
ns
DZL
L
L
-20V ≤ꢀV
Figure 1a
≤ꢀ+25V, 4.5V ≤ꢀV
≤5.5V,
CM
CC
Driver Enable Time
t
3500
ns
D
Driver Disable Time From Low
Driver Disable Time From High
t
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 5
100
100
ns
ns
DLZ
L
L
t
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 4
L L
DHZ
Driver Enable Time from
Shutdown to Output High
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 4
(Note 5)
L
L
t
170
μs
DLZ(SHDN)
Driver Enable Time from
Shutdown to Output Low
R ꢀ=ꢀ110Ω,ꢀC = 50pF, Figure 4
(Note 5)
L
L
t
170
800
μs
DHZ(SHDN)
Time to Shutdown
t
(Note 5)
50
ns
SHDN
RECEIVER (Note 6)
Receiver Propagation Delay
t
t
C
C
= 15pF, Figure 6 and Figure 7
= 15pF, Figure 6 and Figure 7
200
30
ns
ns
RPLH, RPHL
L
L
Receiver Output Skew
t
RSKEW
(Note 7)
Receiver Enable to Output
High
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S2 closed,
Figure 8
L
L
t
50
50
50
50
ns
ns
ns
ns
RZH
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S1 closed,
L
L
Receiver Enable to Output Low
t
RZL
RLZ
RHZ
Figure 8
Receiver Disable Time from
Low
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S1 closed,
L
L
t
Figure 8
Receiver Disable Time from
High
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S2 closed,
L
L
t
Figure 8
Receiver Enable from Shutdown
to Output High
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S2 closed,
Figure 8
L
L
t
170
μs
μs
RLZ(SHDN)
Receiver Enable from Shutdown
to Output Low
R ꢀ=ꢀ1kΩ,ꢀC = 15pF, S2 closed,
L
L
t
170
800
RHZ(SHDN)
Figure 8
Time to Shutdown
t
(Note 5)
50
ns
SHDN
Delay to Fail-Safe Operation
t
10
μs
D_FS
Maxim Integrated
│ 5
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Switching Electrical Characteristics (MAX14776E) (continued)
(V
= 3.0V to 5.5V, T = T
to T
, unless otherwise noted. Typical values are at V
= 3.3V and T = +25°C.) (Note 2)
CC A
CC
A
MIN
MAX
Note 2: All devices are 100% production tested at T = +25°C. Specifications over temperature are guaranteed by design.
A
Note 3:ꢀ ΔV ꢀandꢀΔV
are the changes in V
and V , respectively, when the DI input changes state.
OD
OC
OD OC
Note 4:ꢀ Theꢀshort-circuitꢀcurrentꢀisꢀ200mAꢀ(max)ꢀforꢀaꢀshortꢀperiodꢀ(35μs,ꢀtyp).ꢀIfꢀtheꢀshortꢀcircuitꢀpersists,ꢀtheꢀoutputsꢀareꢀthenꢀsetꢀ
to high impedance for 300ms (typ).
Note 5: Shutdown is enabled when RE is high and DE is low. If the enable inputs are in this state for less than 50ns, the device is
guaranteed not to enter shutdown. If the enable inputs are held in this state for at least 800ns, the device is guaranteed to
have entered shutdown.
Note 6: Capacitive load includes test probe and fixture capacitance.
Note 7: Guaranteed by design. Not production tested.
375Ω
A
A
RL
2
VOD
VOD
60Ω
+
-
VCM
VOC
RL
2
B
B
375Ω
(b)
(a)
Figure 1. Driver DC Test Load
A
DI
V
OD
R
L
C
L
B
Figure 2. Driver Timing Test Circuit
Maxim Integrated
│ 6
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
t
LH
P 3ns, t P 3ns
HL
V
CC
50%
50%
DI
GND
1/2 V
t
O
DPHL
t
DPLH
B
A
1/2 V
O
V
O
V
= V - V
A B
DIFF
V
0
O
80%
80%
V
DIFF
20%
20%
-V
O
t
LH
t
HL
t
|t
- t
|
DSKEW = DPLH DPHL
Figure 3. Driver Propagation Delays
A
S1
DI
V
GND OR V
CC
OUT
CC
D
DE
50%
B
C
50pF
L
R
110I
L =
GND
t
DZH
DE
250mV
V
OUT
OH
50%
GENERATOR
GND
50I
t
DHZ
Figure 4. Driver Enable and Disable Times (t
, t )
DHZ DZH
Maxim Integrated
│ 7
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
V
CC
R
110I
L =
A
B
S1
DI
GND OR V
OUT
CC
D
C
50pF
L =
DE
GENERATOR
50I
V
CC
DE
50%
GND
t
DZL
t
DLZ
V
CC
50%
OUT
250mV
V
OL
Figure 5. Driver Enable and Disable Times (t
, t )
DZL DLZ
A
RECEIVER
OUTPUT
R
ATE
V
ID
B
Figure 6. Receiver Propagation Delay Test Circuit
Maxim Integrated
│ 8
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
t
LH
P 3ns, t P 3ns
HL
A
B
1V
-1V
t
t
RPHL
RPLH
V
V
OH
OL
V
V
CC
CC
RO
2
2
t
|t
- t
|
RSKEW = RPHL RPLH
Figure 7. Receiver Propagation Delays
+1.5V
-1.5V
S3
R
1kI
S1
S2
L
V
CC
RO
V
R
ID
C
L
15pF
GNDB
GND
RE
GENERATOR
50I
V
CC
V
CC
S1 CLOSED
S2 OPEN
S3 = -1.5V
S1 OPEN
S2 CLOSED
S3 = +1.5V
RE
50%
GND
50%
RE
GND
t
t
RZL
RZH
V
V
CC
OH
V
CC
2
V
CC
RO
RE
RO
RE
2
GND
V
OL
V
CC
V
CC
S1 OPEN
S2 CLOSED
S3 = +1.5V
S1 CLOSED
S2 OPEN
50%
50%
S3 = -1.5V
GND
GND
t
t
RLZ
RHZ
V
CC
V
OH
0.25V
RO
RO
0.25V
V
OL
GND
Figure 8. Receiver Enable and Disable Times
Maxim Integrated
│ 9
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Typical Operating Characteristics
(V
= 3.3V, T = +25°C, unless otherwise noted.)
A
CC
SUPPLY CURRENT
vs. DRIVER DATA RATE
SUPPLY CURRENT
vs. DRIVER DATA RATE
DRIVER CURRENT vs.
VCC VOLTAGE
(VCC = 3.3V)
(VCC = 5V)
toc01
toc02
toc03
80
70
80
70
60
50
40
30
20
10
0
90
80
70
60
50
40
30
20
10
0
RL = 60
60
50
40
30
20
10
0
RL = 60
RL = 120
RL = 120
No Load
No Load
0.01
0.1
1
10
0.01
0.1
1
10
3.0
3.5
4.0
VCC (V)
4.5
5.0
5.5
DRIVER DATA RATE (Mbps)
DRIVER DATA RATE (Mbps)
DRIVER OUTPUT SHORT CIRCUIT
CURRENT vs. VOLTAGE
MAX14775 DRIVER PROPAGATION
DELAY vs TEMPERATURE
MAX14776 DRIVER PROPAGATION
DELAY vs TEMPERATURE
toc06
toc04
toc05
20
0
20
18
16
14
12
10
8
500
450
400
350
300
250
200
150
100
tDPHL, VCC = 3.3V
tDPLH, VCC = 3.3V
-20
-40
tDPLH, VCC = 3.3V
tDPHL, VCC = 3.3V
-60
-80
-100
-120
-140
-160
-180
-200
tDPLH, VCC = 5V
6
4
tDPHL, VCC = 5V
2
tDPLH, VCC = 5V
tDPHL, VCC = 5V
OUTPUT IS HIGH
5 15 25 35 45 55 65
0
-65 -55 -45 -35 -25 -15 -5
-40 -25 -10
5
20 35 50 65 80 95 110 125
TEMPERATURE (ºC)
-40 -25 -10
5
20 35 50 65 80 95 110 125
TEMPERATURE (ºC)
DRIVER VOLTAGE (V)
DRIVER OUTPUT SHORT CIRCUIT
CURRENT vs. VOLTAGE
DRIVER DIFFERENTIAL OUTPUT
VOLTAGE vs. LOAD CURRENT
DRIVER DIFFERENTIAL OUTPUT
VOLTAGE vs. TEMPERATURE
toc09
toc07
toc08
200
180
160
140
120
100
80
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
OUTPUT IS LOW
VCC = 5V
VCC = 5V
VCC = 3.3V
VCC = 3.3V
60
40
20
LOAD = 60
0
RL = 54
-20
-65 -55 -45 -35 -25 -15 -5
5
15 25 35 45 55 65
0
25
50
75
100
125
150
-40 -25 -10
5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
DRIVER VOLTAGE (V)
LOAD CURRENT (mA)
Maxim Integrated
│ 10
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Typical Operating Characteristics (continued)
(V
= 3.3V, T = +25°C, unless otherwise noted.)
A
CC
RO OUTPUT HIGH
vs SOURCE CURRENT
RO OUTPUT LOW
vs SINK CURRENT
toc10
toc11
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
6
5
4
3
2
1
0
VCC = 5V
VCC = 5V
VCC = 3.3V
VCC = 3.3V
0
10
20
30
40
50
0
10
20
30
40
50
SINK CURRENT (mA)
SOURCE CURRENT (mA)
MAX14775 RECEIVER PROPAGATION
DELAY vs TEMPERATURE
MAX14776 RECEIVER PROPAGATION
DELAY vs TEMPERATURE
toc12
toc13
50
45
40
35
30
25
20
15
10
5
200
180
160
140
120
100
80
tRPHL, VCC = 3.3V
tRPHL, VCC = 3.3V
tRPLH, VCC = 3.3V
tRPLH, VCC = 3.3V
tRPHL, VCC = 5V
tRPLH, VCC = 5V
60
tRPLH, VCC = 5V
tRPHL, VCC = 5V
40
20
0
0
-40 -25 -10
5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10
5
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Maxim Integrated
│ 11
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Pin Configurations
VCC
8
B
7
A
6
GND
5
TOP VIEW
+
RO
RE
DE
DI
1
2
3
4
8
7
6
5
VCC
B
MAX14775E
MAX14776E
MAX14775E
MAX14776E
A
*
+
GND
1
2
3
4
RO
RE
DE
DI
SOIC
TDFN-EP
3mm x 3mm
* Exposed Pad. Connect to GND
Pin Description
PIN
NAME
FUNCTION
1
RO
Receiver Data Output. See the Function Tables for more information.
Receiver Output Enable. Drive RE low or connect to GND to enable RO. Drive RE high to disable
the receiver. RO is high impedance when RE is high. Drive RE high and DE low to force the IC into
low-power shutdown mode.
2
RE
Driver Output Enable. Drive DE high to enable the driver. Drive DE low or connect to GND to disable
the driver. Drive DE low and RE high to force the IC into low-power shutdown mode.
3
4
DE
DI
Driver Input. With DE high, a low on DI forces the noninverting output (A) low and the inverting out-
put (B) high. Similarly, a high on DI forces the noninverting output high and the inverting output low.
5
6
7
8
GND
A
Ground
Noninverting Driver Output/Receiver Input
Inverting Driver Output/Receiver Input
B
V
Power Supply Input. Bypass V ꢀtoꢀGNDꢀwithꢀaꢀ0.1μFꢀcapacitorꢀasꢀcloseꢀasꢀpossibleꢀtoꢀtheꢀdevice.
CC
CC
Exposed Pad. TDFN package only. Connect EP to GND. EP is not intended as the main ground
connection.
–
EP
Maxim Integrated
│ 12
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Function Tables
TRANSMITTING
INPUTS
OUTPUTS
RE
X
DE
1
DI
1
B
A
0
1
1
0
1
0
X
0
0
X
X
High Impedance
High Impedance
0
Shutdown. A and B are high impedance.
1
Note: X = Don’t care.
RECEIVING
INPUTS
OUTPUTS
Time from Last
A-B Transition
RE
DE
(V - V )
RO
A
B
0
≥ +200mV
-200mV < (V - V ) < +200mV
Always
1
X
X
Indeterminate.
RO is latched to previous value.
< t
0
A
B
D_FS
-40mV < (V - V ) < +40mV
> t
1
0
0
0
1
1
X
X
X
1
A
B
D_FS
≤ - 200mV
Always
0
Open/Shorted
> t
1
D_FS
X
X
X
X
High impedance
Shutdown. RO is high impedance.
0
Note: X = Don’t care.
Maxim Integrated
│ 13
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
When a fault is detected on A or B, the affected driver out-
put is switched into a high-impedance state. After 300ms
(typ),ꢀtheꢀdriverꢀoutputꢀisꢀre-enabledꢀforꢀ30μsꢀ(typ).ꢀIfꢀtheꢀ
fault condition persists, the driver output is again disabled.
If the fault has been removed, the driver outputs remain
on and the transceiver operates normally.
Detailed Description
The MAX14775E/MAX14776E half-duplex transceivers
are optimized for RS-485/RS-422 applications that require
up to ±65V protection from faults on communication bus
lines. These devices contain one differential driver and
one differential receiver. The devices feature a 1/3 unit
load, allowing up to 100 transceivers on a single bus.
Driving a non-terminated cable may cause the voltage
seen at the driver outputs (A or B) to exceed the absolute
maximum voltage rating if the DI input is switched during
a ±65V fault on the A or B pins. Therefore, a termina-
tion resistor is recommended in order to maximize the
overvoltage fault protection while the DI input is being
switched.
The MAX14775E supports data rates up to 20Mbps. The
MAX14776E supports data rates up to 500kbps.
Driver
The driver accepts a single-ended, logic-level input (DI) and
transfers it to a differential RS-485 level output on the A and
B driver outputs.
If the DI input does not change state while the fault con-
dition is present, the MAX14775E/MAX14776E will with-
stand up to ±65V on the RS-485 inputs, regardless of the
termination status of the data cable.
Set the driver enable input (DE) low to disable the driver. A
and B are high impedance when the driver is disabled.
Receiver
Fail-Safe
The receiver accepts a differential, RS-485 level input on
the A and B inputs and transfers it to a single-ended, logic-
level output (RO).
The devices’ receiver features symmetrical thresholds to
improve the duty cycle of the received signal, ensuring that
it is 50% when the received signal amplitude is small.
Additionally, a high input hysteresis (250mV, typ) increases
the resilience to noise on the receiver.
Drive the receiver enable input (RE) low to enable the
receiver. Driver RE high to disable the receiver. RO is high
impedance when RE is high.
The MAX14775E/MAX14776E also include a fail-safe
feature that ensures the receiver output (RO) is high when
the receiver inputs are shorted or open, or when they are
connected to a differentially terminated transmission line
Low-Power Shutdown
Drive DE low and RE high for at least 800ns to put
the MAX14775E/MAX14776E into low-power shutdown
mode.ꢀSupplyꢀcurrentꢀdropsꢀtoꢀ20μAꢀwhenꢀtheꢀdeviceꢀisꢀ
in shutdown mode.
with all drivers disabled for longer than t ꢀ(10μs,ꢀtyp).ꢀ
D_FS
Hot-Swap Functionality
Hot-Swap Inputs
A glitch protection feature ensures that the MAX14775E/
MAX14776E will not accidentally enter shutdown mode
due to logic skews between DE and RE when switching
between transmit and receive modes.
Inserting circuit boards into a hot, or powered backplane
may cause voltage transients on DE, RE, and receiver
inputs A and B that can lead to data errors. For example,
upon initial circuit board insertion, the processor under-
goes a power-up sequence. During this period, the high-
impedance state of the output drivers makes them unable
to drive the MAX14775E/MAX14776E enable inputs to
a defined logic level. Meanwhile, leakage currents of up
toꢀ10μAꢀfromꢀtheꢀhigh-impedanceꢀoutput,ꢀorꢀcapacitivelyꢀ
±65V Fault Protection
The driver outputs/receiver inputs of transceivers connected
to an industrial RS-485 network often experience faults
when shorted to voltages that exceed the -7V to +12V
input range specified in the EIA/TIA-485 standard. Under
such circumstances, ordinary RS-485 transceivers that
have a typical absolute maximum voltage rating of -8V to
+12.5V require costly external protection devices which
can compromise the RS-485 performance. To reduce
system complexity and the need for external protection,
the driver outputs/receiver inputs of the MAX14775E/
MAX14776E are designed to withstand voltage faults of up
to ±65V with respect to ground without damage. Protection
is guaranteed regardless whether the transceiver is active,
in shutdown or without power.
coupled noise from V
or GND, could cause an input
CC
to drift to an incorrect logic state. To prevent such a
condition from occurring, the MAX14775E/MAX14776E
features hot-swap input circuitry on DE and RE to safe-
guard against unwanted driver activation during hot-swap
situations. When VCC rises, an internal pulldown circuit
holds DE low and REꢀ highꢀ forꢀ atꢀ leastꢀ 10μs.ꢀAfterꢀ theꢀ
initial power-up sequence, the internal pulldown/pullup
circuitry becomes transparent, resetting the hot-swap
tolerable inputs.
Maxim Integrated
│ 14
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Thermal Shutdown Protection
Power Considerations for the MAX14775E/
MAX14776E
The MAX14775E/MAX14776E feature thermal-shutdown
protection circuitry to protect the device. When the junction
temperature exceeds +165°C (typ), the driver outputs are
disabled and RO is high impedance. Driver and receiver
outputs are re-enabled when the junction temperature falls
below 150°C (typ).
At high data rates, the power dissipation of an RS-485
transceiver can be high. The power dissipation of a half-
duplex transceiver is determined by a number of factors,
including:
●
●
●
●
The data rate
The time that the driver is transmitting
The termination impedance
The power supply voltage
Applications Information
100 Transceivers on the Bus
The MAX14775E/MAX14776E transceivers have 0.32-
unit load receiver, allowing up to 100 MAX14775E/
MAX14776E transceivers connected in parallel on a
shared communication line. Connect any combination of
these devices, and/or other RS-485 devices, for a maximum
of 32 unit loads to the line.
Higher data rates result in higher power dissipation due
to switching losses in the transceiver. Switching losses
increase even more when capacitance is applied to the A
and B pins. External capacitance should be kept to a minimum
to help reduce power dissipation at high data rates.
Similarly, the power dissipation in a transceiver is much
higher when the driver is transmitting, compared to when
the transceiver is receiving. In half-duplex communication,
the period of transmission relative to the idle or receiving
intervals (i.e., the duty cycle) should be taken into consideration
when calculating the average power dissipation.
Typical Application
The MAX14775E/MAX14776E half-duplex transceivers are
designed for bidirectional data communications on
multipoint bus transmission lines. Figure 9 shows a typical
network applications circuit. To minimize reflections, the bus
should be terminated at the receiver inputs in its characteristics
impedance, and stub lengths off the main line should be
kept as short as possible.
B
B
DI
D
D
DI
120
120
DE
RE
DE
RE
A
A
RO
R
R
RO
MAX14775E
MAX14776E
DI
DE RE RO
DI
DE RE
RO
Figure 9. Typical RS-485 Network
Maxim Integrated
│ 15
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
The line termination resistance/impedance determines
the driver’s load current during transmission and the
ESD Protection
ESD protection structures are incorporated on all pins
to protect against electrostatic discharge encountered
during handling and assembly. The driver outputs and
receiver inputs of the MAX14775E/MAX14776E have
extra protection against static electricity. The ESD structures
withstand high ESD in normal operation and when powered
down. After an ESD event, the devices keep working without
latch-up or damage.
differential output voltage (V ) on the driver is
OD
determined by the supply voltage. A higher supply voltage
results in a larger differential output voltage at the driver
driving the line, which in turn results in a higher current
draw from the supply (I ).
CC
The power dissipation in the chip is calculated as the
product of supply current times supply voltage, subtracting
2
the power dissipated in the external termination resistor :
ESD protection can be tested in various ways. The
transmitter outputs and receiver inputs of the devices
are characterized for protection to the cable-side ground
(GNDB) to the following limits:
2
P
DIS
= (V
x I ) – (V
/R
LOAD
)
CC
CC
OD
Use the Typical Operation Characteristics to determine
the supply current at a given supply voltage and data rate.
●
●
±8kV HBM
For example, assuming a data rate of 20Mbps with a 5V
±5kVꢀusingꢀtheꢀContactꢀDischargeꢀmethodꢀspecifiedꢀ
in the IEC 61000-4-2
supply on a fully loaded bus (R ꢀ=ꢀ60Ω),ꢀweꢀcanꢀcalculateꢀ
L
that the power dissipation (at room temperature) is:
2
P
= (5V x 70mA) – (4.3V /60Ω)ꢀ=ꢀ42mW
DIS
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.
Ensure that power dissipation of the transceiver is kept
below the value listed in the Absolute Maximum Ratings
section to protect the device from entering thermal shut-
down or from damage. If the calculated power dissipation
nears the specified limits, select a package with a lower
thermal resistance which also allows for higher power
dissipation.
Human Body Model (HBM)
Figure 10 shows the HBM test model and Figure 11
shows the current waveform it generates when
discharged in a low-impedance state. This model
consistsofa100pFcapacitorchargedtotheESDvoltageof
interest, which is then discharged in to the test device
throughꢀaꢀ1.5kΩꢀresistor.
R
R
D
C
1MΩ
1500Ω
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
I 100%
P
90%
I
r
DISCHARGE
RESISTANCE
CHARGE-CURRENT-
LIMIT RESISTOR
AMPS
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
36.8%
C
100pF
STORAGE
CAPACITOR
s
10%
0
SOURCE
TIME
0
t
RL
t
DL
CURRENT WAVEFORM
Figure 10. Human Body ESD Test Model
Figure 11. Human Body Current Waveform
Maxim Integrated
│ 16
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
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. 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.
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 MAX14775E/
MAX14776E help in designing equipment to meet IEC
61000-4-2 without the need for additional ESD protection
components.
R
R
C
I
D
50MΩ TO 100MΩ
330Ω
100%
90%
DISCHARGE
RESISTANCE
CHARGE-CURRENT-
LIMIT RESISTOR
HIGH-
VOLTAGE
DC
DEVICE
UNDER
TEST
C
s
150pF
STORAGE
CAPACITOR
SOURCE
10%
t = 0.7ns TO 1ns
r
t
30ns
60ns
Figure 12. IEC 61000-4-2 ESD Test Model
Figure 13. IEC 61000-4-2 ESD Generator Current Waveform
Maxim Integrated
│ 17
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Functional Diagram
R
RO
RE
A
B
SHUTDOWN
DE
DI
D
MAX14775E
MAX14776E
Maxim Integrated
│ 18
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Ordering Information
Package Information
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.
PART
TEMP RANGE
PIN-PACKAGE
MAX14775EASA+
MAX14775EASA+T
MAX14775EATA+
MAX14775EATA+T
MAX14776EASA+
MAX14776EASA+T
MAX14776EATA+
MAX14776EATA+T
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
8 SOIC
8 SOIC
8 TDFN-EP
8 TDFN-EP
8 SOIC
PACKAGE PACKAGE
OUTLINE
NO.
LAND PATTERN
NO.
TYPE
CODE
8 SOIC
S8+4
21-0041
21-0137
90-0096
90-0059
8 SOIC
8 TDFN-EP
T833+2
8 TDFN-EP
8 TDFN-EP
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and Reel
Chip Information
PROCESS: BiCMOS
Maxim Integrated
│ 19
www.maximintegrated.com
MAX14775E/MAX14776E
±65V Fault Protected 500kpbs/20Mbps
Half-Duplex RS-485/RS-422 Transceivers
Revision History
REVISION REVISION
PAGES
DESCRIPTION
CHANGED
NUMBER
DATE
0
9/16
Initial release
—
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.
2016 Maxim Integrated Products, Inc.
│ 20
MAX14775EASA+ 相关器件
| 型号 | 制造商 | 描述 | 价格 | 文档 |
| MAX14775EEVKIT | MAXIM | Operates From a Single 3V to 5V Supply | 获取价格 |
|
| MAX14776E | MAXIM | Operates From a Single 3V to 5V Supply | 获取价格 |
|
| MAX14776E | ADI | ±65V故障保护500Kbps/20Mbps半双工RS-485/RS-422收发器 | 获取价格 |
|
| MAX14776EASA+ | MAXIM | Line Transceiver, | 获取价格 |
|
| MAX14777 | MAXIM | Quad Beyond-the-Rails -15V to 35V Analog Switch | 获取价格 |
|
| MAX14777 | ADI | 四通道、-15V至+35V超摆幅模拟开关 | 获取价格 |
|
| MAX14777GTP | MAXIM | Quad Beyond-the-Rails -15V to 35V Analog Switch | 获取价格 |
|
| MAX14777GTP+ | MAXIM | SPST, | 获取价格 |
|
| MAX14777GTP+T | MAXIM | SPST, | 获取价格 |
|
| MAX14778 | MAXIM | Dual 25V Above- and Below-the-Rails 4:1 Analog Multiplexer | 获取价格 |
|
MAX14775EASA+ 相关文章
Bourns 密封通孔金属陶瓷微调电位计产品选型手册(英文版)
- 2024-09-20
- 6
Bourns 精密环境传感器产品选型手册(英文版)
- 2024-09-20
- 9
Bourns POWrTher 负温度系数(NTC)热敏电阻手册 (英文版)
- 2024-09-20
- 8
Bourns GMOV 混合过压保护组件产品选型手册(英文版)
- 2024-09-20
- 6
