Designed for low-power applications with high output-voltage swings at low currents, Allegro MicroSystems Europe’s ACS722 and ACS723 current-sensor ICs deliver high accuracy along with internal galvanic isolation. Typical applications include motor control, load detection and management, switched-mode power supplies, solar inverters, and overcurrent fault protection.
The new devices are true bidirectional ±5-A or unidirectional 10-A sensor ICs that provide an economical and precise solution for ac or dc current sensing in non-automotive applications. Each IC incorporates a precise, low-offset, linear Hall sensor circuit with a copper conduction path located near the surface of the die. To optimize accuracy, the magnetic field is closely located to the Hall transducer, and the devices are calibrated after packaging.
The terminals of the conductive path are electrically isolated from the sensor leads. This allows the current-sensor ICs to be used in high-side current-sense applications without resorting to high-side differential amplifiers or other costly isolation techniques. The devices are certified to 2400-V rms isolation, and can be used in ac line-tied applications. The internal resistance of this conductive path is typically 0.65 mΩ, leading to low power loss.
The 5-V ACS723 maintains higher sensitivity than the 3.3-V ACS722 for the same current range. For example, the ACS723LLCTR-05AB-T has a sensitivity of 400 mV/A, compared with 264 mV/A for the ACS722LLCTR-05AB-T.
The sensor ICs come in a low-profile, surface-mount SOIC8 package.