Hall effect sensors improve contactless switching accuracy
Diodes Incorporated has introduced a family of micro-power 8-bit Hall effect sensors for contactless switching in portable consumer, domestic and industrial applications. The AH8500, AH8501, AH8502 and AH8503 sensors operate over a supply range of 1.6-3.6V and a magnetic range of ±400G, minimising current consumption down to micro-power levels.
The AH8500 and higher accuracy AH8501, which both feature an enable pin, draw a current of just 9μA in sleep mode (default mode). The devices achieve a typical current consumption of only 12μA at 20Hz and 1.16mA at the maximum 7.14kHz sample rate. The AH8502 and AH8503, feature a control pin and a default-mode sampling rate of 24Hz. These two devices consume 13μA and allow the control pin to increase the sampling rate up to 7.14kHz, with a current consumption of 1.16mA.
The higher accuracy, gain trimmed AH8501 and AH8503 devices help minimise any sample-to-sample variation and the need for any sensor calibration. The AH8501 and AH8503 have a sensitivity accuracy of 3% at room temperature and a null offset below 1% of supply voltage.
This linear Hall effect sensor family features internal ADCs and DACs and has a typical span linearity greater than 99.7% ensuring high linearity with the external magnetic field. A low input-referred noise characteristic of less than 0.36G helps minimise output fluctuation. High sensitivity, typically 2.25mV/G at 1.6V to 4.12mV/G at 3.6V, enables designers to either boost field detection ranges or make use of weaker, lower cost magnets.
With their chopper-stabilised architecture and advanced low temperature coefficient, the sensors help to minimise output offsets, drift and internal stress effects, ensuring greater stability and robustness over the full -40 to +85°C operating temperature range. These devices also feature a high ESD of 6kV.
Packaged in the small footprint, low profile U-DFN2020-6, the Hall effect sensors are suitable for a variety of proximity, position, and travel and level detection applications. The standard accuracy AH8500/AH8502 and high accuracy AH8501/AH8503 sensors are priced at $0.29 and $0.33 each, respectively, in 10,000 unit quantities.