参数资料
| 型号： | ADM2490EBRWZ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 5/16页 |
| 文件大小： | 0K |
| 描述： | IC TXRX RS-485 ISOLATED 16-SOIC |
| 产品培训模块： | iCoupler Digital Isolater Technology |
| 标准包装： | 47 |
| 系列： | iCoupler® |
| 类型： | 收发器，隔离式 |
| 驱动器/接收器数： | 1/1 |
| 规程： | RS422/RS485 |
| 电源电压： | 3V，5V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-SOIC（0.295"，7.50mm 宽） |
| 供应商设备封装： | 16-SOIC |
| 包装： | 管件 |
| 产品目录页面： | 790 (CN2011-ZH PDF) |
ADM2490E
Rev. A | Page 13 of 16
THERMAL SHUTDOWN
The ADM2490E contains thermal-shutdown circuitry that protects
the part from excessive power dissipation during fault conditions.
Shorting the driver outputs to a low impedance source can result in
high driver currents. The thermal sensing circuitry detects the
increase in die temperature under this condition and disables
the driver outputs. This circuitry is designed to disable the driver
outputs when a die temperature of 150°C is reached. As the device
cools, the drivers are re-enabled at a temperature of 140°C.
FAIL-SAFE RECEIVER INPUTS
The receiver inputs include a fail-safe feature that guarantees a
logic high on the RxD pin when the A and B inputs are floating
or open-circuited.
MAGNETIC FIELD IMMUNITY
The limitation on the magnetic field immunity of the iCoupler
is set by the condition in which an induced voltage in the receiv-
ing coil of the transformer is large enough to either falsely set or
reset the decoder. The following analysis defines the conditions
under which this may occur. The 3 V operating condition of
the ADM2490E is examined because it represents the most
susceptible mode of operation.
The pulses at the transformer output have an amplitude greater
than 1 V. The decoder has a sensing threshold of about 0.5 V,
thus establishing a 0.5 V margin in which induced voltages can
be tolerated.
The voltage induced across the receiving coil is given by
N
n
r
dt
dβ
V
n
,
2
,
1
;
2
K
=
π
=
∑
where:
β is the magnetic flux density (gauss).
N is the number of turns in the receiving coil.
rn is the radius of the nth turn in the receiving coil (cm).
Given the geometry of the receiving coil and an imposed
requirement that the induced voltage is, at most, 50% of the
0.5 V margin at the decoder, a maximum allowable magnetic
field can be determined using Figure 22.
MAGNETIC FIELD FREQUENCY (Hz)
1k
10k
100k
100M
1M
10M
100
10
1
0.1
0.01
0.001
MA
X
IMU
M
A
L
O
W
A
B
L
E
MA
G
N
ET
IC
F
L
UX
D
E
NS
IT
Y
(
kG
AU
S
)
0
58
89
-0
10
Figure 22. Maximum Allowable External Magnetic Flux Density
For example, at a magnetic field frequency of 1 MHz, the
maximum allowable magnetic field of 0.2 kgauss induces a
voltage of 0.25 V at the receiving coil. This is about 50% of the
sensing threshold and does not cause a faulty output transition.
Similarly, if such an event occurs during a transmitted pulse and
is the worst-case polarity, it reduces the received pulse from
>1.0 V to 0.75 V, still well above the 0.5 V sensing threshold
of the decoder.
Figure 23 shows the magnetic flux density values in terms of
more familiar quantities, such as maximum allowable current
flow at given distances away from the ADM2490E transformers.
MAGNETIC FIELD FREQUENCY (Hz)
1k
10k
100k
100M
1M
10M
DISTANCE = 1m
DISTANCE = 100mm
DISTANCE = 5mm
1000
100
0.1
1
10
0.01
M
A
X
IM
U
M
A
L
OW
ABL
E
CURRE
N
T
(
kA)
05
889
-01
1
Figure 23. Maximum Allowable Current for
Various Current-to-ADM2490E Spacings
With combinations of strong magnetic field and high frequency,
any loops formed by PCB traces can induce error voltages large
enough to trigger the thresholds of succeeding circuitry. Care
should be taken in the layout of such traces to avoid this
possibility.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ADM2490EBRWZ-REEL7 | 功能描述:IC TXRX RS-485 HS ESD 16-SOIC RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器，接收器，收发器 系列:iCoupler® 标准包装:27 系列:- 类型:收发器 驱动器/接收器数:3/3 规程:RS232，RS485 电源电压:4.75 V ~ 5.25 V 安装类型:表面贴装 封装/外壳:28-SOIC（0.295"，7.50mm 宽） 供应商设备封装:28-SOIC 包装:管件 |
| ADM2490EBRWZ-REEL71 | 制造商:AD 制造商全称:Analog Devices 功能描述:High Speed, ESD-Protected, Full-Duplex, iCoupler, Isolated RS-485 Transceiver |
| ADM2491E | 制造商:AD 制造商全称:Analog Devices 功能描述:High Speed, ESD-Protected, Half-/Full-Duplex, iCoupler Isolated RS-485 Transceiver |
| ADM2491EBRWZ | 功能描述:IC TXRX ISO RS-485 HS ESD 16SOIC RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器，接收器，收发器 系列:- 产品培训模块:RS-232 & USB Transceiver 标准包装:2,000 系列:- 类型:收发器 驱动器/接收器数:1/1 规程:RS232 电源电压:3 V ~ 5.5 V 安装类型:表面贴装 封装/外壳:16-SSOP（0.209"，5.30mm 宽） 供应商设备封装:16-SSOP 包装:带卷 (TR) 其它名称:296-19849-2 |
| ADM2491EBRWZ | 制造商:Analog Devices 功能描述:IC RS-485 TRANSCEIVER 5.5V SOIC-16 制造商:Analog Devices 功能描述:IC, RS-485 TRANSCEIVER, 5.5V, SOIC-16 |
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