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Linear Output Magnetic Field Sensor AD22151 FUNCTIONAL BLOCK DIAGRAM

FEATURES Adjustable Offset to Unipolar or Bipolar Operation Low Offset Drift Over Temperature Range Gain Adjustable Over Wide Range Low Gain Drift Over Temperature Range Adjustable First Order Temperature Compensation Ratiometric to VCC

REF

VCC/2 TEMP REF

OUT AMP

AD22151

APPLICATIONS Automotive Throttle Position Sensing Pedal Position Sensing Suspension Position Sensing Valve Position Sensing Industrial Absolute Position Sensing Proximity Sensing

ISOURCE

SWITCHES

DEMOD

VCC

GENERAL DESCRIPTION

The AD22151 is a linear magnetic field transducer. The sensor output is a voltage proportional to a magnetic field applied perpendicularly to the package top surface.

NC R1

R2

The sensor combines integrated bulk Hall cell technology and instrumentation circuitry to minimize temperature related drifts associated with silicon Hall cell characteristics. The architecture maximizes the advantages of a monolithic implementation while allowing sufficient versatility to meet varied application requirements with a minimum number of components. Principle features include dynamic offset drift cancellation and a built-in temperature sensor. Designed for single +5 volt supply operation, the AD22151 achieves low drift offset and gain operation over –40°C to +150°C. Temperature compensation can accommodate a number of magnetic materials commonly utilized in economic position sensor assemblies.

0.1␮F R3

OUTPUT

NC = NO CONNECT

GND

AD22151

Figure 1. Typical Bipolar Configuration with Low (< –500 ppm) Compensation VCC

The transducer may be configured for specific signal gains dependent upon application requirements. Output voltage can be adjusted from fully bipolar (reversible) field operation to fully unipolar field sensing.

R1

R4 NC

The voltage output achieves near rail-to-rail dynamic range, capable of supplying 1 mA into large capacitive loads. The signal is ratiometric to the positive supply rail in all configurations.

R2 0.1␮F R3

OUTPUT

GND

NC = NO CONNECT

AD22151

Figure 2. Typical Unipolar Configuration with High (≈ –2000 ppm) Compensation

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