Figure 2. Typical application circuits
GND
A1244
VCC
V+
0.01 糉
ECU
R
SENSE
C
BYP
GND
A1244
VCC
V+
0.01 糉
R
SENSE
C
BYP
(A) Low side sensing
(B) High side sensing
Amp
Regulator
Clock/Logic
Hall Element
Low-Pass
Filter
Chopper Stabilization Technique
When using Hall-effect technology, a limiting factor for
switchpoint accuracy is the small signal voltage developed
across the Hall element. This voltage is disproportionally small
relative to the offset that can be produced at the output of the
Hall sensor IC. This makes it difficult to process the signal while
maintaining an accurate, reliable output over the specified oper-
ating temperature and voltage ranges. Chopper stabilization is
a unique approach used to minimize Hall offset on the chip. The
patented Allegro technique, namely Dynamic Quadrature Offset
Cancellation, removes key sources of the output drift induced by
thermal and mechanical stresses. This offset reduction technique
is based on a signal modulation-demodulation process. The
undesired offset signal is separated from the magnetic field-
induced signal in the frequency domain, through modulation.
The subsequent demodulation acts as a modulation process for
the offset, causing the magnetic field-induced signal to recover
its original spectrum at base band, while the DC offset becomes
a high-frequency signal. The magnetic-sourced signal then can
pass through a low-pass filter, while the modulated DC offset is
suppressed. The chopper stabilization technique uses a 350 kHz
high frequency clock. For demodulation process, a sample and
hold technique is used, where the sampling is performed at twice
the chopper frequency. This high-frequency operation allows
a greater sampling rate, which results in higher accuracy and
faster signal-processing capability. This approach desensitizes
the chip to the effects of thermal and mechanical stresses, and
produces devices that have extremely stable quiescent Hall out-
put voltages and precise recoverability after temperature cycling.
This technique is made possible through the use of a BiCMOS
process, which allows the use of low-offset, low-noise amplifiers
in combination with high-density logic integration and sample-
and-hold circuits.
Figure 3. Chopper stabilization circuit (Dynamic Quadrature Offset Cancellation)
Chopper-Stabilized, Two Wire
Hall-Effect Latch
A1244
8
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
A1302KUA-T
IC SENSOR HALL EFFECT 3-SIP
A1323LLHLT-T
IC SENSOR HALL EFFECT SOT23W
A1351LKTTN-T
IC SENSOR HALL EFFECT 4-SIP
A1354KKT-T
IC SENSOR HALL EFFECT 4-SIP
A1356LKB-T
IC SENSOR HALL EFFECT 3 SIP
A1361LKTTN-T
IC HALL EFFECT SENSOR LN 4-SIP
A1374EKB-T
IC SENSOR HALL EFFECT PREC 3-SIP
A1422LK
IC SENSOR HALL EFFECT AC 4-SIP
相关代理商/技术参数
A1245LLHLT-I1-T
功能描述:IC HALL EFFECT LATCH SOT23-3 制造商:allegro microsystems, llc 系列:- 包装:带卷（TR） 零件状态:有效 功能:卡销 技术:霍尔效应 极化:南极 感应范围:4mT 跳闸，-4mT 释放 测试条件:-40°C ~ 150°C 电压 - 电源:3 V ~ 24 V 电流 - 电源（最大值）:6.9mA 电流 - 输出（最大值）:- 输出类型:开路漏极 特性:- 工作温度:-40°C ~ 150°C（TA） 封装/外壳:TO-236-3，SC-59，SOT-23-3 供应商器件封装:SOT-23-3 标准包装:3,000
A1245LLHLT-I2-T
功能描述:IC HALL EFFECT LATCH SOT23-3 制造商:allegro microsystems, llc 系列:- 包装:带卷（TR） 零件状态:有效 功能:卡销 技术:霍尔效应 极化:南极 感应范围:4mT 跳闸，-4mT 释放 测试条件:-40°C ~ 150°C 电压 - 电源:3 V ~ 24 V 电流 - 电源（最大值）:5mA 电流 - 输出（最大值）:- 输出类型:开路漏极 特性:- 工作温度:-40°C ~ 150°C（TA） 封装/外壳:TO-236-3，SC-59，SOT-23-3 供应商器件封装:SOT-23-3 标准包装:3,000
A1245LLHLX-I1-T
功能描述:IC HALL EFFECT LATCH SOT23-3 制造商:allegro microsystems, llc 系列:- 包装:带卷（TR） 零件状态:有效 功能:卡销 技术:霍尔效应 极化:南极 感应范围:4mT 跳闸，-4mT 释放 测试条件:-40°C ~ 150°C 电压 - 电源:3 V ~ 24 V 电流 - 电源（最大值）:6.9mA 电流 - 输出（最大值）:- 输出类型:开路漏极 特性:- 工作温度:-40°C ~ 150°C（TA） 封装/外壳:TO-236-3，SC-59，SOT-23-3 供应商器件封装:SOT-23-3 标准包装:10,000
A1245LLHLX-I2-T
功能描述:IC HALL EFFECT LATCH SOT23-3 制造商:allegro microsystems, llc 系列:- 包装:带卷（TR） 零件状态:有效 功能:卡销 技术:霍尔效应 极化:南极 感应范围:4mT 跳闸，-4mT 释放 测试条件:-40°C ~ 150°C 电压 - 电源:3 V ~ 24 V 电流 - 电源（最大值）:5mA 电流 - 输出（最大值）:- 输出类型:开路漏极 特性:- 工作温度:-40°C ~ 150°C（TA） 封装/外壳:TO-236-3，SC-59，SOT-23-3 供应商器件封装:SOT-23-3 标准包装:10,000
A1245LUA-I1-T
功能描述:IC HALL EFFECT LATCH 3SIP 制造商:allegro microsystems, llc 系列:- 包装:散装 零件状态:有效 功能:卡销 技术:霍尔效应 极化:南极 感应范围:4mT 跳闸，-4mT 释放 测试条件:-40°C ~ 150°C 电压 - 电源:3 V ~ 24 V 电流 - 电源（最大值）:6.9mA 电流 - 输出（最大值）:- 输出类型:开路漏极 特性:- 工作温度:-40°C ~ 150°C（TA） 封装/外壳:3-SIP 模块 供应商器件封装:3-SIP 标准包装:500
A1245LUA-I2-T
功能描述:IC HALL EFFECT LATCH 3SIP 制造商:allegro microsystems, llc 系列:- 包装:散装 零件状态:有效 功能:卡销 技术:霍尔效应 极化:南极 感应范围:4mT 跳闸，-4mT 释放 测试条件:-40°C ~ 150°C 电压 - 电源:3 V ~ 24 V 电流 - 电源（最大值）:5mA 电流 - 输出（最大值）:- 输出类型:开路漏极 特性:- 工作温度:-40°C ~ 150°C（TA） 封装/外壳:3-SIP 模块 供应商器件封装:3-SIP 标准包装:500
A12466
制造商:BACO Controls Inc 功能描述:
A1247
制造商:Hakko 功能描述:Tip,B,929 -2/939,903 Used With Soldering Stations