Monolithic, Unipolar Hall-effect Switches Designed for Proximity Sensing in Battery-powered Applications

31 August 2023 - 0 Comments

Diodes Incorporated has introduced two new portfolios of monolithic, unipolar Hall-effect switches designed for proximity sensing in battery-powered applications. With an ultra-low 1.1µA supply current at 1.85V, and 1.6µA at 1.6V to 5.5V, these AH138x and AH139x series devices are ideal for battery-powered portable equipment like smartphones, laptops, and wearables. These devices are also suitable for domestic appliances, game consoles, and industrial hardware use. To ensure their suitability in small form-factor applications, all devices are provided in the industry’s smallest packages: DFN1010-4 and DFN1410-4.

The 1.6V to 5.5V operating voltage of these Hall-effect switches allows them to be powered directly from a portable device’s battery, eliminating the area and cost of power conversion. Output 1 in the dual-output AH139x series responds to a North pole, while Output 2 responds to a South pole with typical operating points of 25G (AH1391) and 30G (AH1392). The single output on the AH138x series responds to a South pole on the part-marking side with typical operating points of 18G (AH1381), 30G (AH1382), and 45G (AH1383).

The tight operating window of these switches ensures a lower magnetic spread, while their chopper-stabilized design provides minimal switch point drift and superior temperature stability. For robustness, these devices have strong human body model (HBM) electrostatic discharge (ESD) protection: 8kV for the AH138x and 6kV for the AH139x series. In addition, these devices have push-pull outputs that do not require an external pull-up resistor, simplifying system design, saving board space, and lowering the bill of materials.

Features

Two Monolithic Unipolar Hall Switches
Supply Voltage of 1.6V to 3.6V
Micro Power Operation
Dual Outputs for Independent Pole Detection for Design Flexibility
Internal Pull-Up and Pull-Down Capability
Chopper Stabilized Design
Superior Temperature Stability
Extremely Low Switch-Point Drift
Insensitive to Physical Stress
Good RF Noise Immunity
Operating Temperature Range: -40°C to +85°C
2kV ESD on Supply and Output Pins

Applications

Smart Cover or Dock Detect for Cellular Phones and Tablet
Position Detect for Digital Still, Video Cameras and Handheld Gaming Consoles
Door, Lids and Tray Position Detect Switches Home Appliances and Industrial Applications
Level, Proximity and Position Switches
Contact-Less Switches in Home Appliances and Industrial Applications

Availability & Pricing

In 1,000 piece quantities, the AH138x series is available in DFN packages at $0.17 and in SOT23 packages at $0.16. The AH139x series is available in DFN packages at $0.18 in 1,000 piece quantities.