Magnetic Switch
IST8508
SOT23-3L package
Analog and I2C digital output
Dynamic range: ± 500 uT
Output Data Rate: 200 Hz
Sensitivity: 660 or 1320 LSB/Gauss
Hysteresis: < 0.1 % FS
Linearity: < 0.1 % FS
The iST8508 is a 3D omni-polar magnetic switch featuring low hysteresis, low power consumption, and adjustable magnetic operating points that can be as low as 15 G. The iST8508 Hall effect sensor IC is fabricated with mixed-signal CMOS technology. It comprises one AMR sensor, one Hall plate, and a CMOS output driver, mainly designed for battery operation, and hand-held equipment (such as Cellular and Cordless Phone, PAD). The total power consumption in normal operation is typically 18.81 μW with a 3.3 V power source. A magnetic field of sufficient strength will turn the output on (low voltage). The output will be turned off (high voltage) when the magnetic field ceases to exist. More precisely, when the absolute value of the applied magnetic flux density (B) is larger than the absolute value of the operating point (BOP), the output will be turned low and kept low until the absolute value of B becomes lower than the absolute value of the release point (BRP), below which point the output returns to high voltage. The IST8508 is available in the SOT23-3L package. The operating temperature range of the iST8508 is from -40 °C to 85 °C. To minimize the BOM cost, capacitors of the MLCC type are supported, and only one external component is needed to complete the application circuit.
Features
Micropower consumption is ideal for battery-powered applications
Omni-polar (operation with the magnetic field of either north or south pole), easy to use as output
Input Voltage Range: 2.5 V to 5.5 V
Very high sensitivity hall sensor
Chopper stabilized amplifier stage
Good RF noise immunity
SOT23-3L package
No need for a pull-high resistor
Block diagram
Application
Cover switch in clam-shell cellular phones
Cover switch in Notebook PC/PAD
Contact-less switch in consumer products
Solid State Switch
Handheld Wireless Handset Awake Switch
Lid close sensor for battery-powered device
Magnet proximity sensor for reed switch replacement