Diodes Incorporated has expanded its AH371xQ series of automotive-compliant Hall effect latches with the new AH3711Q model. The device is designed for motor control applications requiring very low magnetic thresholds and bipolar switching. It features a proprietary Hall plate design and is targeted at brushless DC (BLDC) motor control, valve operation, linear and incremental rotary encoders, and position-sensing functions. Vehicle applications include window power-lift and sunroof movement, tailgate opening/closing mechanisms, seat adjustment motors, cooling fans, water/oil pumps, and speed measurement.
The AH3711Q provides magnetic operate (BOP) and release (BRP) points covering ±10 Gauss. This ultra-high sensitivity allows detection of weaker magnetic fields, enabling the use of smaller magnets to reduce system size and bill-of-materials cost. It also supports aggressive duty-cycle reduction to lower power consumption and extend battery life.
The latch operates over a 3 V to 27 V range. It includes a reverse blocking diode with Zener clamp on the supply and an output with overcurrent limit and Zener clamp, providing protection against 40 V load dumps, reverse polarity, and short circuits. The device has an 8 kV HBM and 1 kV CDM ESD rating.
It uses a chopper-stabilized design that minimizes switch-point drift across the -40°C to +150°C temperature range and offers high resistance to physical stress during PCB assembly. Power-on time is typically 13 µs. The device features open-drain outputs for external pull-up flexibility.
Magnetic operating and release polarity is opposite for different packages. For SOT23 (Type S) and SIP-3 (Bulk Pack) packages, the south pole is required on the part-marking side. For the SC59 package, the south pole is required on the non-part-marking side.
The AH3711Q is available at $0.20 in 2,000-piece quantities. A standard-compliance version, AH3711, is also available for industrial and commercial applications.
