Electronics Weekly
The first current sensor, ACS37630, is designed to be sat on top of a bus bar and partly surrounded by a U-core magnetic field concentrator.
“Its vertical Hall technology enables sensing parallel to the package surface, ideal for system integration with U-core magnets,” according to the company. “This contactless non-invasive current sensing solution eliminates the need for C-core magnets.”
Bandwidth is up to 250kHz) and 1.6µs is the typical output response time.
Operation is from 5V and over the automotive Grade 0 temperature range of -50 to +150°C.
The output is quiescent at 2.5V and sensitivity is 4mV/gauss.
Little other public information is available, and data sheets have to be requested.
Applications are foreseen in electric vehicle traction inverters and battery management systems.
ACS37035 is the second current sensor, this time with current flowing through an isolated 1mΩ path within the package.
The barrier is rated to withstand 4.2kVrms in the LA package and is rated to 1kVac (±1.4kVdc) ‘basic’ and 500Vac (±700Vdc) ‘reinforced’.
There are three types, all automotive qualified to AEC-Q100, with ranges of ±20A, ±40A or ±65A, with sensitivities of 100, 50 or 20mV/A respectively, and operating from 5V, 5V or 3.3V respectively. The quiescent output is half the supply voltage.
Bandwidth is 1MHz and response is within 0.45µs.
“Its differential sensing capability, combined with a CMMR (common-mode rejection ratio) of 4mA/Gauss, provides high immunity to external magnetic fields,” said Allegro, which claims a ±3% sensitivity error over temperature and a maximum offset of ±15 mV.
It envisages applications in motor control, load management and switch-mode power supplies.
A89347 is the fan driver IC, also qualified to AEC-Q100 for automotive use, and proposed for electric vehicle seat fans and battery cooling fans.
The topology is sensor-less sinusoidal three-phase, with integrated closed-loop speed control.
“Additionally, a customisable speed curve, configured via eeprom, allows for tailored performance in various fan applications,” said Allegro.
Slew-rate control, lock detection and a 10μA stand-by mode are other functions.
Evaluation boards and support resources are planned for all three ICs.
Allegro web pages:
ACS37630
ACS37035
A89347 (available in the summer).
All three data sheets have to be requested. Only the ACS37035 has a public data brief.
To learn more about Allegro’s latest motor control and thermal management solutions, visit ACS37035, ACS37630 and A89347.
