SS40A
CMOS Omnipolar High Sensitivity Micropower Hall Switch
Packages
Features and Benefits
1. Operation down to 2.5V
2. Wide operating voltage range
3. High sensitivity for direct reed switch replacement
applications
4. Omnipolar, output switches with absolute
5. value of North or South pole from magnet
6. Temperature compensation
7. Open-Collector pre-driver
8. 60V maximum withstand voltage
9. Reverse polarity protection
10. Package: TO-92S(SIP)
3 pin SIP (suffix UA)
Functional Block Diagram
Application Examples
1. Brush-less DC Motor
2. Brush-less DC Fan
3. Revolution counting
4. Speed measurement
General Description:
The SS40A 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. An internal bandgap regulator is used to provide temperature compensated supply
voltage for internal circuits and allows a wide operating supply range.
The output transistor of the SS40A 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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V1.10 May 1, 2011
SECELECTRONICS [ SEC Electronics Inc. ]
