收藏本站
ACS709
High Bandwidth, Fast Fault Response Current Sensor IC
In Thermally Enhanced Package
Functional Description
Overcurrent Fault Operation
The primary concern with high-speed fault detection is that noise
may cause false tripping. Various applications have or need to
be able to ignore certain faults that are due to switching noise
or other parasitic phenomena, which are application dependant.
The problem with simply trying to filter out this noise up front is
that in high-speed applications, with asymmetric noise, the act of
filtering introduces an error into the measurement. To get around
this issue, and allow the user to prevent the fault signal from
being latched by noise, a circuit was designed to slew the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ
pin voltage based on the value of the capacitor from that pin to
ground. Once the voltage on the pin falls below 2 V, as estab-
lished by an internal reference, the fault output is latched and
pulled to ground quickly with an internal N-channel MOSFET.
Fault Walk-through
The following walk-through references various sections and
2. When the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ pin voltage reaches approximately 2 V, the
fault is latched, and an internal NMOS device pulls the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ
pin voltage to approximately 0 V. The rate at which the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ
pin slews downward (see [4] in the figure) is dependent on the
external capacitor, C OC , on the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ pin.
3.When the FAULT_EN pin is brought low, the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ pin starts
resetting if no OC Fault condition exists. The internal NMOS
pull-down turns off and an internal PMOS pull-up turns on (see
[7] if the OC Fault condition still exists).
4. The slope, and thus the delay, on the fault is controlled by the
capacitor, C OC , placed on the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ pin to ground. During this
portion of the fault (when the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ pin is between V CC and
2 V), there is a 3 mA constant current sink, which discharges
C OC . The length of the fault delay, t, is equal to :
C OC ( V CC – 2 V )
attributes in the figure below.This figure shows different
fault set/reset scenarios and how they relate to the voltages on
the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ pin, FAULT_EN pin, and the internal Overcurrent
(OC) Fault node, which is invisible to the customer.
t =
3 mA
where V CC is the device power supply voltage.
(1)
1.Because the device is enabled (FAULT_EN is high for a mini-
mum period of time, the Fault Enable Delay, t FED , 15 μ s typical)
and there is an OC fault condition, the device ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ pin starts
discharging.
5. The ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ pin did not reach the 2 V latch point before the
OC fault condition cleared. Because of this, the fixed 3 mA
current sink turns off, and the internal PMOS pull-up turns on to
recharge C OC through the ˉF ˉAˉ ˉUˉ ˉLˉ ˉTˉ pin.
V CC
1
1
1
FAULT
(Output)
2V
4
2
6
t FED
4
5
6
4
2
6
8
4
2
7
3
0V
FAULT_EN
(Input)
OC Fault
Condition
(Active High)
Time
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
12
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
ACS710KLATR-6BB-NL-T IC CURRENT SENSOR 120KHZ 16-SOIC
ACS710KLATR-6BB-T SENSOR CURRENT 16SOIC
ACS711ELCTR-25AB-T SENSOR CURRENT 25A 3.3V 8-SOIC
ACS713ELCTR-20A-T SENSOR CURRENT 20A 5V UNI 8-SOIC
ACS714LLCTR-50A-T SENSOR CURRENT 50A 5V BI 8SOIC
ACS715LLCTR-20A-T SENSOR CURRENT 20A 5V UNI 8-SOIC
ACS716KLATR-12CB-T IC CURRENT SENSOR 120KHZ 16SOIC
ACS716KLATR-6BB-NL-T IC CURRENT SENSOR 120KHZ 16-SOIC
相关代理商/技术参数
ACS709LLFTR-10BB-T 功能描述:SENSOR CURRENT 10A 制造商:allegro microsystems, llc 系列:- 包装:带卷（TR） 零件状态:不適用於新設計 用于测量:AC/DC 传感器类型:霍尔效应，开环 电流 - 检测:10A 通道数:1 输出:比率，电压 灵敏度:85mV/A 频率:DC ~ 120kHz 线性度:±0.25% 精度:±2% 电压 - 电源:4 V ~ 5.5 V 响应时间:4μs 电流 - 电源（最大值）:14.5mA 工作温度:-40°C ~ 150°C 极化:双向 安装类型:表面贴装 封装/外壳:24-QSOP 标准包装:7,500
ACS709LLFTR-20BB-T 功能描述:SENSOR CURR 37.5A 5V BI 24QSOP RoHS:是 类别:传感器，转换器 >> 电流 系列:- 标准包装:10 系列:*
ACS709LLFTR-20BB-T 制造商:Allegro MicroSystems 功能描述:Current Sensor IC
ACS709LLFTR-35BB-T 功能描述:SENSOR CURRENT 75A 5V BI 24QSOP- RoHS:是 类别:传感器，转换器 >> 电流 系列:- 标准包装:10 系列:*
ACS709LLFTR-35BB-T 制造商:Allegro MicroSystems LLC 功能描述:Current Sensor IC
ACS709LLFTR-35BB-TMxx 制造商:Allegro MicroSystems LLC 功能描述:Fast Fault Response Current Sensor IC 制造商:Allegro Microsystems 功能描述:IC, ACS709LLFTR-35BB-TMXX
ACS710 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:120 kHz Bandwidth, High Voltage Isolation Current Sensor with Integrated Overcurrent Detection
ACS710KLATR-10BB-NL-T 功能描述:SENSOR CURRENT 10A 制造商:allegro microsystems, llc 系列:- 零件状态:不適用於新設計 用于测量:AC/DC 传感器类型:霍尔效应，开环 电流 - 检测:10A 通道数:1 输出:比率，电压 灵敏度:85mV/A 频率:120kHz 线性度:±0.25% 精度:±1.6% 电压 - 电源:3 V ~ 5.5 V 响应时间:4μs 电流 - 电源（最大值）:14.5mA 工作温度:-40°C ~ 125°C（TA） 极化:双向 安装类型:表面贴装 封装/外壳:16-SOIC（0.295"，7.50mm 宽） 标准包装:3,000