參數(shù)資料
型號: EVAL-ADM2490EEBZ
廠商: Analog Devices Inc
文件頁數(shù): 5/16頁
文件大?。?/td> 0K
描述: BOARD EVAL FOR ADM2490
標(biāo)準(zhǔn)包裝: 1
系列: *
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
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.
相關(guān)PDF資料
PDF描述
MAX17108ETI+ IC LEVEL SHIFTER 10CH 28TQFN
EET-UQ2S221BA CAP ALUM 220UF 420V 20% SNAP
H3CWH-2018M IDC CABLE - HKC20H/AE20M/HPL20H
M1BXK-1436R IDC CABLE - MSR14K/MC14M/X
H3DKH-1418M IDC CABLE - HKR14H/AE14M/HPK14H
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
EVAL-ADM2491EEBZ 功能描述:BOARD EVAL FOR ADM2491 RoHS:是 類別:編程器,開發(fā)系統(tǒng) >> 評估演示板和套件 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 主要目的:數(shù)字電位器 嵌入式:- 已用 IC / 零件:AD5258 主要屬性:- 次要屬性:- 已供物品:板 相關(guān)產(chǎn)品:AD5258BRMZ1-ND - IC POT DGTL I2C1K 64P 10MSOPAD5258BRMZ10-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ100-ND - IC POT DGTL I2C 100K 64P 10MSOPAD5258BRMZ50-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ1-R7-ND - IC POT DGTL I2C 1K 64P 10MSOPAD5258BRMZ10-R7-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ50-R7-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ100-R7-ND - IC POT DGTL I2C 100K 64P 10MSOP
EVAL-ADM2582EEB1Z 功能描述:BOARD EVAL FOR ADM2582E RoHS:否 類別:編程器,開發(fā)系統(tǒng) >> 評估演示板和套件 系列:* 標(biāo)準(zhǔn)包裝:1 系列:- 主要目的:電信,線路接口單元(LIU) 嵌入式:- 已用 IC / 零件:IDT82V2081 主要屬性:T1/J1/E1 LIU 次要屬性:- 已供物品:板,電源,線纜,CD 其它名稱:82EBV2081
EVAL-ADM2582EEBZ 功能描述:BOARD EVAL FOR ADM2582 RoHS:是 類別:編程器,開發(fā)系統(tǒng) >> 評估演示板和套件 系列:isoPower® 標(biāo)準(zhǔn)包裝:1 系列:- 主要目的:數(shù)字電位器 嵌入式:- 已用 IC / 零件:AD5258 主要屬性:- 次要屬性:- 已供物品:板 相關(guān)產(chǎn)品:AD5258BRMZ1-ND - IC POT DGTL I2C1K 64P 10MSOPAD5258BRMZ10-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ100-ND - IC POT DGTL I2C 100K 64P 10MSOPAD5258BRMZ50-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ1-R7-ND - IC POT DGTL I2C 1K 64P 10MSOPAD5258BRMZ10-R7-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ50-R7-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ100-R7-ND - IC POT DGTL I2C 100K 64P 10MSOP
EVAL-ADM2587EEB1Z 功能描述:界面開發(fā)工具 Low EMI 4-layer board for ADM258E RoHS:否 制造商:Bourns 產(chǎn)品:Evaluation Boards 類型:RS-485 工具用于評估:ADM3485E 接口類型:RS-485 工作電源電壓:3.3 V
EVAL-ADM2587EEBZ 功能描述:BOARD EVAL FOR ADM2587 RoHS:是 類別:編程器,開發(fā)系統(tǒng) >> 評估演示板和套件 系列:isoPower® 標(biāo)準(zhǔn)包裝:1 系列:- 主要目的:數(shù)字電位器 嵌入式:- 已用 IC / 零件:AD5258 主要屬性:- 次要屬性:- 已供物品:板 相關(guān)產(chǎn)品:AD5258BRMZ1-ND - IC POT DGTL I2C1K 64P 10MSOPAD5258BRMZ10-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ100-ND - IC POT DGTL I2C 100K 64P 10MSOPAD5258BRMZ50-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ1-R7-ND - IC POT DGTL I2C 1K 64P 10MSOPAD5258BRMZ10-R7-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ50-R7-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ100-R7-ND - IC POT DGTL I2C 100K 64P 10MSOP