Document
SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Features
Micropower consumption for battery powered applications Omnipolar, output switches with absolute value of North or South pole from magnet Operation down to 2.5V High sensitivity for direct reed switch replacement applications
3 pin SOT23 (suffix SO)
3 pin SIP (suffix UA)
Chopper stabilized amplifier stage2.Description
The S248 Omnipolar Hall effect sensor IC is fabricated from mixed signal CMOS technology .It incorporates advanced chopper-stabilization techniques to provide accurate and stable magnetic switch points. The circuit design provides an internally controlled clocking mechanism to cycle power to the Hall element and analog signal processing circuits. This serves to place the high current-consuming portions of the circuit into a “Sleep” mode. Periodically the device is “Awakened” by this internal logic and the magnetic flux from the Hall element is evaluated against the predefined thresholds. If the flux density is above or below the Bop/Brp thresholds then the output transistor is driven to change states accordingly. While in the “Sleep” cycle the output transistor is latched in its previous state. The design has been optimized for service in applications requiring extended operating lifetime in battery powered systems. The output transistor of the S248 will be latched on (Bop) in the presence of a sufficiently strong South or North magnetic field facing the marked side of the package. The output will be latched off (Brp) in the absence of a magnetic field.
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Applications
Solid state switch Handheld Wireless Handset Awake Switch Lid close sensor for battery powered devices Magnet proximity sensor for reed switch replacement in low duty cycle applications
1
V2.00
Mar 28, 2009
Datasheet pdf - http://www.DataSheet4U.co.kr/
SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Typical Application Circuit
SEC's pole-independent sensing technique allows for operation with either a north pole or south pole magnet orientation, enhancing the manufacturability of the device. The state-of-the-art technology provides the same output polarity for either pole face. It is strongly recommended that an external bypass capacitor be
connected (in close proximity to the Hall sensor) between the supply and ground of the device to reduce both external noise and noise generated by the chopper-stabilization technique. This is especially true due to the relatively high impedance of battery supplies.
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Functional Block Diagram
Pin Definitions and Descriptions
2
V2.00
Mar 28, 2009
Datasheet pdf - http://www.DataSheet4U.co.kr/
SS248
CMOS Omnipolar High Sensitivity Micropower Hall Switch
SOT Pin № 1 2 3 SIP Pin № 1 3 2 Name VDD OUT GND Type Supply Output Ground Function Supply Voltage pin Open Drain Output pin Ground pin
Internal Timing Circuit
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Current Period
Iaw
Sample & Output Latched
Iav
g Isp A.