参数资料
型号: MAX1480EAEPI+
厂商: Maxim Integrated Products
文件页数: 9/19页
文件大小: 0K
描述: IC RS485/RS422 DATA INTRFC 28DIP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 14
类型: 收发器
驱动器/接收器数: 1/1
规程: RS422,RS485
电源电压: 4.5 V ~ 5.5 V
安装类型: 通孔
封装/外壳: 28-DIP(0.600",15.24mm)
供应商设备封装: 28-PDIP
包装: 管件
产品目录页面: 1402 (CN2011-ZH PDF)
MAX1480E/MAX1490E
±15kV ESD-Protected, Isolated RS-485/RS-422
Data Interfaces
______________________________________________________________________________________
17
MAX1480EC/MAX1490EA/MAX1490EB. Connections
and components from one side should not be locat-
ed near those of the other side.
A shield trace connected to the ground on each side
of the barrier can help intercept capacitive currents
that might otherwise couple into the signal path. In a
double-sided or multilayer board, these shield traces
should be present on all conductor layers.
Try to maximize the width of the isolation barrier
wherever possible; a clear space of at least 0.25
inches between ground and isolated common is
suggested.
Pullup and LED Drive Resistors
The MAX1480EA/MAX1480EC/MAX1490EA/MAX1490EB
are specified and characterized using the resistor val-
ues shown in Tables 1 and 2. Altering the recommend-
ed values can degrade performance.
DI and DE are intended to be driven through a series
current-limiting resistor. Directly grounding these
pins destroys the device.
The DI and DE (MAX1480EA/MAX1480EC only) inputs
are the cathodes of LEDs whose anodes are connected
to the supply. These points are best driven by a CMOS-
logic gate with a series resistor to limit the current. The
resistor values shown in Tables 1 and 2 are recommend-
ed when the 74HC86 gate or equivalent is used. These
values may need to be adjusted if a driving gate with dis-
similar series resistance is used.
All pullup resistors are based on optocoupler specifica-
tions in order to optimize the devices’ data-transfer rates.
Isolated Common Connection
The isolated common may be completely floating with
respect to the logic ground and the effective network
ground. The receiver input resistors cause the isolated
common voltage to go to the mean voltage of the receiver
inputs. If using shielded cable, connect the isolated com-
mon to the shield through a 100
resistor. In the case of
the MAX1490EA/MAX1490EB, each shield should have its
own 100
resistor (Figures 1, 2, 15, and 16).
Double-Isolated RS-485 Repeater
The RS-422/RS-485 standard is specified for cable
lengths up to 4000 feet. When approaching or exceeding
the specified maximum cable length, a ground-potential
difference of several tens of volts can easily develop.
This difference can be either DC, AC, at power-line fre-
quency, or any imaginable noise or impulse waveform. It
is typically very low impedance so that if a connection
between the two grounds is attempted, very large cur-
SHIELD (OPTIONAL)
NOTE: RESISTORS R5 AND R6 PROTECT
THE MAX1490EA/MAX1490EB FROM TRANSIENT
CURRENTS BETWEEN SHIELD AND
TRANSMISSION LINES.
120
120
120
A
B
Z
Y
Z
R3
R4
R5, 100
SH1
SH2
R1
R2
R6, 100
DI
VIN
+5V
C1
22
F
C2
0.1
F
LOGIC GROUND
ISOLATION BARRIER
ISOLATED COMMON
DRIVER INPUT
RECEIVER OUTPUT
DI
RO
74HC86
OR EQUIVALENT
SHIELD (OPTIONAL)
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
AC1 (MAKE NO CONNECTION)
AC2 (MAKE NO CONNECTION)
ISO VCC1
ISO RO DRV
D2
D1
VCC2
VCC1
A
B
Z
Y
VCC3
SD
FS
GND1
16
15
14
13
9
10
11
12
ISO COM1
ISO DI DRV
ISO VCC2
ISO RO LED
GND2
RO
VCC4
DI
MAX845E
MAX488E MAX490E
D
DI
RO
120
B
A
R
MAX1490EA/
MAX1490EB
270pF
4kV
Figure 16. Typical Full-Duplex RS-485/RS-422 Network
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相关代理商/技术参数
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MAX1480EAEPI+ 功能描述:RS-422/RS-485 接口 IC Isolated RS-422/485 Data Interface RoHS:否 制造商:Maxim Integrated 数据速率:1136 Kbps 工作电源电压:3 V to 5.5 V 电源电流:5.9 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-28 封装:Tube
MAX1480ECCPI 功能描述:RS-422/RS-485 接口 IC RoHS:否 制造商:Maxim Integrated 数据速率:1136 Kbps 工作电源电压:3 V to 5.5 V 电源电流:5.9 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-28 封装:Tube
MAX1480ECCPI+ 功能描述:RS-422/RS-485 接口 IC Isolated RS-422/485 Data Interface RoHS:否 制造商:Maxim Integrated 数据速率:1136 Kbps 工作电源电压:3 V to 5.5 V 电源电流:5.9 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-28 封装:Tube
MAX1480ECEPI 功能描述:RS-422/RS-485 接口 IC RoHS:否 制造商:Maxim Integrated 数据速率:1136 Kbps 工作电源电压:3 V to 5.5 V 电源电流:5.9 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-28 封装:Tube
MAX1480ECEPI+ 功能描述:RS-422/RS-485 接口 IC Isolated RS-422/485 Data Interface RoHS:否 制造商:Maxim Integrated 数据速率:1136 Kbps 工作电源电压:3 V to 5.5 V 电源电流:5.9 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-28 封装:Tube