A1324
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A1324, A1325, and A1326 Low Noise, Linear Hall Effect Sensor ICs with Analog Output Features and Benefits These ratiometric Hall effect sensor ICs provide a voltage output that is proportional to the applied magnetic field. They feature a quiescent voltage output of 50% of the supply voltage. The A1324/25/26 feature factory programmed sensitivities of 5.0 mV/G, 3.125 mV/G, and 2.5 mV/G, respectively. • Temperature-stable quiescent output voltage and sensitivity • Output voltage proportional to magnetic flux density • Low-noise output increases accuracy • Precise recoverability after temperature cycling • Ratiometric rail-to-rail output • Wide ambient temperature range: –40°C to 150°C • Immune to mechanical stress • Solid-state reliability • Enhanced EMC performance for stringent automotive applications New applications for linear output Hall-effect devices, such as displacement, angular position, and current measurement, require high accuracy in conjunction with small package size. The Allegro™ A1324, A1325, and A1326 linear Hall-effect sensor ICs are designed specifically to achieve both goals. This temperature-stable device is available in a miniature surface mount package (SOT23W) and an ultra-mini through-hole single in-line package. The features of these linear devices make them ideal for use in automotive and industrial applications requiring high accuracy, and operate through an extended temperature range, –40°C to 150°C. Each BiCMOS monolithic circuit integrates a Hall element, temperature-compensating circuitry to reduce the intrinsic sensitivity drift of the Hall element, a small-signal high-gain amplifier, a clamped low-impedance output stage, and a proprietary dynamic offset cancellation technique. These devices are available in a 3-pin ultra-mini SIP package (UA), and a 3-pin surface mount SOT-23 style package (LH). Both are lead (Pb) free, with 100% matte tin leadframe plating. Approximate footprint Functional Block Diagram V+ To All Subcircuits Tuned Filter Dynamic Offset Cancellation Trim Control

Linear Hall Effect Sensor ICs with Analog Output Selection Guide Pin-out Diagrams 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com

Linear Hall Effect Sensor ICs with Analog Output OPERATING CHARACTERISTICS Valid throughout TA range, CBYpass = 0.1 pF, VCC = 5 V; unless otherwise noted Continued on the next page... Allegro Microsystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com

Linear Hall Effect Sensor ICs with Analog Output OPERATING CHARACTERISTICS (continued) Valid throughout TA range, CBYpass = 0.1 pF, VCC = 5 V; unless otherwise noted 11 G (gauss) = 0.1 mT (millitesla). 2See Characteristic Definitions section. 3fc varies up to approximately ±20% over the full operating ambient temperature range and process. 4Percent change from actual value at Vcc = 5 V, for a given temperature. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com

Linear Hall Effect Sensor ICs with Analog Output Characteristic Definitions Power-On Time When the supply is ramped to its operating voltage, the device output requires a finite time to react to an input magnetic field. Power-On Time is defined as the time it takes for the output voltage to begin responding to an applied magnetic field after the power supply has reached its minimum specified operating voltage, VCC(min). V VCC t1= time at which power supply reaches minimum specified operating voltage t2= time at which output voltage settles within ±10% of its steady state value under an...

Linear Hall Effect Sensor ICs with Analog Output TA = 25°C, and Sens(25°C)1 is the value of sensitivity at TA = 25°C after temperature cycling TA up to 150°C, down to –40°C, and back to up 25°C. Symmetry Sensitivity Error The magnetic sensitivity of a device is constant for any two applied magnetic fields of equal magnitude and opposite polarities. Linearity Sensitivity Error The 132x is designed to provide linear output in response to a ramping applied magnetic field. Consider two magnetic fields, B1 and B2. Ideally the sensitivity of a device is the same for both fields for a given supply...

Linear Hall Effect Sensor ICs with Analog Output Typical Characteristics (30 pieces, 3 fabrication lots) Average Supply Current versus Ambient Temperature VCC = 5 V 12 11 Average Postive Linearity versus Ambient Temperature VCC = 5 V Average Negative Linearity versus Ambient Temperature VCC = 5 V 104 Average Quiescent Voltage Output Ratiometry versus Ambient Temperature 102.0 VCC 5.5 to 5.0 V Average Sensitivity Ratiometry versus Ambient Temperature Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.alleg

Linear Hall Effect Sensor ICs with Analog Output Typical Characteristics, continued (30 pieces, 3 fabrication lots) Average Absolute Quiescent Voltage Output versus Ambient Temperature VCC = 5 V Quiescent Voltage Output versus Supply Voltage TA = 25°C 3.0 Average Sensitivity versus Supply Voltage TA = 25°C Average Absolute Sensitivity versus Ambient Temperature VCC = 5 V Average Sensitivity Drift versus Ambient Temperature ∆Sensav values relative to 25°C, VCC = 5 V Average Quiescent Voltage Output Drift versus Ambient Temperature ∆VOUT(Q)av values relative to 25°C, VCC = 5 V 10 Allegro...

Linear Hall Effect Sensor ICs with Analog Output Pin numbers in brackets refer to the UA package Typical Application Circuit Chopper Stabilization Technique When using Hall-effect technology, a limiting factor for switchpoint accuracy is the small signal voltage developed across the Hall element. This voltage is disproportionally small relative to the offset that can be produced at the output of the Hall IC. This makes it difficult to process the signal while maintaining an accurate, reliable output over the specified operating temperature and voltage ranges. Chopper stabilization is a...