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[原创] Allegro ACS71020单相AC电源90A监视解决方案

关键词:电源管理 电源监视 ACS71020

时间:2020-01-20 10:27:59       来源:中电网

Allegro MicroSystems公司的ACS71020是单相隔离的AC电源监视集成电路,能大大地简化任何AC电源设备的电源监测.采用基于Allegro公司的霍尔效应电流隔离集成电流传感器技术,得到了加强的电隔离.传感器可以从MCU同样的电源供电,从而不需要多个电源和数字隔离集成电路.绝缘电流测量通过检测集成导体的磁场来实现,从而不需要外接的检测电阻,电流变压器或Rogowski线圈.两个霍尔电极用来测量以确定电场,从而消除了平板磁场所引起的误差.多个参数如带宽,平均时间和故障水平是用户可编程的.用户可编程输入电压的欠压和过压阈值,以及过流故障阈值.1kHz带宽,电流检测范围从0到90A,可选择I2C或SPI数字接口协议,用户可编程EEPROM和集成电荷泵.器件还集成了16位电压和电流ADC.本文介绍了ACS71020主要特性和优势,功能框图,典型应用电路图以及演示板ASEK71020主要元件表和电路图.

The Allegro ACS71020 power monitoring IC greatly simplifies the addition of power monitoring to many AC powered systems. The sensor may be powered from the same supply as the system’s MCU, eliminating the need for multiple power supplies and expensive digital isolation ICs. The device’s construction includes a copper conduction path that generates a magnetic field proportional to applied current. The magnetic field is sensed differentially to reject errors introduced by common mode fields.

Allegro’s Hall-effect-based galvanically isolated current sensing technology achieves reinforced isolation ratings in a small PCB footprint. These features enable isolated current sensing without expensive Rogowski coils, oversized current transformers, isolated operational amplifiers, or the power loss of shunt resistors.

The ACS71020 power monitoring IC offers key power measurement parameters that can easily be accessed through its SPI or I2C digital protocol interfaces. Dedicated and configurable I/O pins for voltage zero crossing, undervoltage and overvoltage reporting, and overcurrent fault detection are also available (in I2C mode). The thresholds for overvoltage, undervoltage, and overcurrent are all user-programmable via EEPROM.

The ACS71020 is provided in a small low-profile surface mount SOIC16 wide-body package, is lead (Pb) free, and is fully calibrated prior to shipment from the Allegro factory. Customer calibration can further increase accuracy in application.

The sensor features all key power measurements, which can be read out through I2C or SPI, as well as dedicated pins for voltage zero crossing (suitable for light-dimming applications) and fast overcurrent fault (for short-circuit detection). As the sensor is isolated, these pins can be easily accessed by the MCU without additional isolation to each signal. These two pins can also be configured to flag a VRMS under/overvoltage.

The ACS71020 is provided in a small, low-profile, surface-mount SOIC16 wide-body package. The ACS71020 is lead (Pb) free, and is fully calibrated prior to shipment from the factory. Further customer calibration in application can improve accuracy.

ACS71020主要特性和优势:

Accurate power monitoring for AC applications
UL certification for reinforced isolation up to 517 VRMS in a single package
Accurate measurements of active, reactive, and apparent power, as well as power factor
Separate RMS and instantaneous measurements for both voltage and current channels
0.85 mΩ primary conductor resistance for low power loss and high inrush current withstand capability
Dedicated voltage zero crossing pin
Overcurrent fault output pin
Hall-effect-based current measurement with common-mode stray field rejection
User-programmable undervoltage and overvoltage thresholds for input voltage as well as overcurrent fault thresholds
1 kHz bandwidth
Current-sensing range from 0 to 90 A
Options for I2C or SPI digital interface protocols
User-programmable EEPROM and integrated charge pump
16-bit voltage and current ADCs

图1.ACS71020功能框图

图2. ACS71020典型应用电路图

演示板ASEK71020

Allegro ACS71020 demo board is pictured in Figure3 below. Refer to Table 1 for symbol names and descriptions of onboard components. Note: Board is pictured without capacitors and resistors attached.

图3.演示板ASEK71020外形图
演示板ASEK71020主要元件表:

图4.演示板ASEK71020电路图
详情请见:
https://www.allegromicro.com/en/products/sense/current-sensor-ics/zero-to-fifty-amp-integrated-conductor-sensor-ics/acs71020
ASEK71020-Eval-Board-User-Manual.pdf
ACS71020-Datasheet.pdf

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