- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383073 > HMC1021S Magnetoresistive Sensor PDF資料下載
參數(shù)資料
| 型號： | HMC1021S |
| 英文描述： | Magnetoresistive Sensor |
| 中文描述： | 磁阻傳感器 |
| 文件頁數(shù)： | 8/15頁 |
| 文件大小： | 190K |
| 代理商： | HMC1021S |
HMC10XX FAMILY
8
Most low field magnetic sensors will be affected by large
magnetic disturbing fields (>4 gauss) that may lead to
output signal degradation. In order to reduce this effect,
and maximize the signal output, a magnetic switching
technique can be applied to the MR bridge that eliminates
the effect of past magnetic history. The purpose of the Set/
Reset (S/R) strap is to restore the MR sensor to its high
sensitivity state for measuring magnetic fields. This is done
by pulsing a large current through the S/R strap. The Set/
Reset (S/R) strap looks like a resistance between the SR+
and SR- pins. This strap differs from the OFFSET strap in
that it is magnetically coupled to the MR sensor in the cross-
axis, or insensitive, direction. Once the sensor is set (or
reset), low noise and high sensitivity field measurement
can occur. In the discussion that follows, the term “set”
refers to either a set or reset current.
The on-chip S/R should be pulsed with a current to realign,
or “flip”, the magnetic domains in the transducer. This pulse
can be as short as two microsecond and on average
consumes less than 1 mA dc when pulsing continuously.
The duty cycle can be selected for a 2
μ
sec pulse every 50
msec, or longer, to conserve power. The only requirement
is that each pulse only drive in one direction. That is, if a
+3.5 amp pulse is used to “set” the sensor, the pulse decay
should not drop below zero current. Any undershoot of the
current pulse will tend to “un-set” the sensor and the
sensitivity will not be optimum.
Using the S/R strap, many effects can be eliminated or
reduced that include: temperature drift, non-linearity er-
rors, cross-axis effects, and loss of signal output due to the
presence of a high magnetic fields. This can be accom-
plished by the following process:
A current pulse, Iset, can be driven from the S/R+ to the
S/R- pins to perform a “SET” condition. The bridge output
can then be measured and stored as Vout(set).
Another pulse of equal and opposite current should be
driven through the S/R pins to perform a "RESET"
condition. The bridge output can then be measured and
stored as Vout(reset).
The bridge output, Vout, can be expressed as:Vout =
[Vout(set) - Vout(reset)]/2. This technique cancels out
offset and temperature effects introduced by the elec-
tronics as well as the bridge temperature drift.
The magnitude of the S/R current pulse depends on the
magnetic noise sensitivity of the application. If the minimum
detectable field for a given application is roughly 500
μ
gauss, then a 2.5 amp pulse (min) is adequate. If the
minimum detectable field is less than 100
μ
gauss, then a
3.5 amp pulse (min) is required. The circuit that generates
the S/R pulse should be located close to the MR sensor and
have good power and ground connections.
There are many ways to design the set/reset pulsing circuit,
though, budgets and ultimate field resolution will determine
which approach will be best for a given application. A simple
set/reset circuit is shown in Figure 4.
Figure 4—Single-Axis Set/Reset Pulse Circuit (1001)
WHAT IS SET/RESETSTRAP
5V
Manual Switch
S/R+
I
0.2μF
25K
3
4
2
1
5,6
7,8
0.1μF
SET
RESET
RESET
RSignal should be in
Signal input
6-9V
S/R-
The magnitude of the set/reset current pulse depends on
the magnetic noise sensitivity of the system. If the minimum
detectable field for a given application is roughly 500
μ
gauss, then a 3 amp pulse (min) is adequate. If the
minimum detectable field is less than 100
μ
gauss, then a
4 amp pulse (min) is required.
The set/reset straps on the Honeywell magnetic sensors
are labeled S/R+ and S/R-. There is no polarity implied
since this is simply a metal strap resistance of typically 1.5
per sensor. Therefore, for a three axis system, the total
series strap resistance is typically 4.5
.
If three axis are used, it is recommended that the straps are
connected in series to insure the same current pulse flows
through all three sensors. Assuming the pulse drive circuitry
has a source impedance of 0.5
, the set/reset current pulse
will effectively drive a 5
load. Now to generate a 3-4 amp
minimum pulse into a 5
load requires a 15-20V supply.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| HMC1021Z | Magnetoresistive Sensor |
| HMC1022 | Magnetoresistive Sensor |
| HMC103 | SPST RF Absorptive Switch |
| HMC104 | SPDT RF Absorptive Switch |
| HMC105 | SPST RF Absorptive Switch |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| HMC1021S | 制造商:Honeywell Sensing and Control 功能描述:MAGNETIC SENSOR |
| HMC1021S-TR | 功能描述:SENSOR LINEAR MAGN 1 AXIS 8-SOIC RoHS:是 類別:傳感器，轉(zhuǎn)換器 >> 磁性 - 霍爾效應(yīng)，數(shù)字式開關(guān)，線性，羅盤 (IC) 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 傳感范圍:20mT ~ 80mT 類型:旋轉(zhuǎn) 電源電壓:4.5 V ~ 5.5 V 電流 - 電源:15mA 電流 - 輸出（最大）:- 輸出類型:數(shù)字式，PWM，8.5 位串行 特點:可編程 工作溫度:-40°C ~ 150°C 封裝/外殼:20-SSOP（0.209"，5.30mm 寬） 供應(yīng)商設(shè)備封裝:20-SSOP 包裝:Digi-Reel® 其它名稱:AS5132-HSST-500DKR |
| HMC1021Z | 功能描述:SENSOR LINEAR MAGN 1 AXIS 8-SIP RoHS:否 類別:傳感器，轉(zhuǎn)換器 >> 磁性 - 霍爾效應(yīng)，數(shù)字式開關(guān)，線性，羅盤 (IC) 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 傳感范圍:20mT ~ 80mT 類型:旋轉(zhuǎn) 電源電壓:4.5 V ~ 5.5 V 電流 - 電源:15mA 電流 - 輸出（最大）:- 輸出類型:數(shù)字式，PWM，8.5 位串行 特點:可編程 工作溫度:-40°C ~ 150°C 封裝/外殼:20-SSOP（0.209"，5.30mm 寬） 供應(yīng)商設(shè)備封裝:20-SSOP 包裝:Digi-Reel® 其它名稱:AS5132-HSST-500DKR |
| HMC1021Z RC | 制造商:Honeywell Sensing and Control 功能描述: |
| HMC1021Z-RC | 功能描述:SENSOR LINEAR MAGN 1 AXIS 8-SIP RoHS:是 類別:傳感器，轉(zhuǎn)換器 >> 磁性 - 霍爾效應(yīng)，數(shù)字式開關(guān)，線性，羅盤 (IC) 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 傳感范圍:20mT ~ 80mT 類型:旋轉(zhuǎn) 電源電壓:4.5 V ~ 5.5 V 電流 - 電源:15mA 電流 - 輸出（最大）:- 輸出類型:數(shù)字式，PWM，8.5 位串行 特點:可編程 工作溫度:-40°C ~ 150°C 封裝/外殼:20-SSOP（0.209"，5.30mm 寬） 供應(yīng)商設(shè)備封裝:20-SSOP 包裝:Digi-Reel® 其它名稱:AS5132-HSST-500DKR |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。