A1308 and A1309 Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package FEATURES AND BENEFITS • 5 V supply operation • QVO temperature coefficient programmed at Allegro™ for improved accuracy • Miniature package options • High-bandwidth, low-noise analog output • High-speed chopping scheme minimizes QVO drift across operating temperature range • Temperature-stable quiescent voltage output and sensitivity • Precise recoverability after temperature cycling • Output voltage clamps provide short-circuit diagnostic capabilities • Undervoltage lockout (UVLO) • Wide ambient temperature range: –40°C to 150°C (SOT-23W), –40°C to 125°C (SIP) • Immune to mechanical stress • Enhanced EMC performance for stringent automotive applications New applications for linear output Hall-effect sensors, such as displacement and angular position, require higher accuracy and smaller package sizes. The Allegro A1308 and A1309 linear Hall-effect sensor ICs have been designed specifically to meet both requirements. These temperature-stable devices are available in both surface-mount and through-hole packages. The accuracy of each device is enhanced via end-of-line optimization. Each device features nonvolatile memory to optimize device sensitivity and the quiescent voltage output (QVO: output in the absence of a magnetic field) for a given application or circuit. This A1308 and A1309 optimized performance is sustained across the full operating temperature range by programming the temperature coefficient for both sensitivity and QVO at Allegro end-of-line test. These ratiometric Hall-effect sensor ICs provide a voltage output that is proportional to the applied magnetic field. The quiescent voltage output is adjusted around 50% of the supply voltage. The features of these linear devices make them ideal for use in automotive and industrial applications requiring high accuracy, and they operate across an extended temperature range, –40°C to 150°C (SOT-23W) or –40°C to 125°C (SIP). Each BiCMOS monolithic circuit integrates a Hall element, temperature-compensating circuitry to reduce the intrinsic Continued on the next page… Functional Block Diagram V+ Tuned Filter Dynamic Offset Cancellation

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package DESCRIPTION (continued) sensitivity drift ofthe Hall element, a small-signal high-gain amplifier, a clamped low-impedance output stage, and a proprietary dynamic offset cancellation technique. The A1308 and A1309 sensor ICs are offered in two package styles. The LH is a SOT-23W style, miniature, low-profile package for surface-mount applications. The UA is a 3-pin, ultramini, single inline package (SIP) for through-hole mounting. Both packages are lead (Pb) free, with 100% matte-tin leadframe...

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount PackagePINOUT DIAGRAMS AND TERMINAL LIST TABLE ua Package Terminal List Table 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 Available in a Miniature, Low-Profile Surface-Mount Package OPERATING CHARACTERISTICS: Valid through TA , CBYpass = 0.1 mF Vcc = 5 V, unless otherwise noted Continued on the next page... 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 Available in a Miniature, Low-Profile Surface-Mount Package OPERATING CHARACTERISTICS (continued): Valid through TA , CBYPASs = 0.1 pF, VCC = 5 V, unless otherwise noted [2] On power-up, the output of the device is held low until VCC exceeds VUVLOhi. After the device is powered, the output remains valid until VCC drops below VUvLoLo, when the output is pulled low. [3] Determined by design and characterization, not evaluated at final test. [4] See the Characteristic Definitions section. [5] fC varies as much as approximately ±20% across the full...

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount PackageCHARACTERISTIC 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, tPO , 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), as shown in Figure 1. Delay to Clamp. A large magnetic input step may cause the clamp to overshoot its steady-state...

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package SensTA – SensIDEAL(TA) SensIDEAL(TA) Sensitivity Drift Due to Package Hysteresis. Package stress and relaxation can cause the device sensitivity at TA = 25°C to change during and after temperature cycling. This change in sensitivity follows a hysteresis curve. For purposes of specification, the Sensitivity Drift Due to Package Hysteresis, ∆SensPKG, is defined as: where Sens(25°C)(1) is the programmed value of sensitivity at TA = 25°C, and Sens(25°C)(2) is the value of sensitivity at TA = 25°C...

Linear Hall-Effect Sensor ICs with Analog Output Available in a Miniature, Low-Profile Surface-Mount Package Undervoltage Lockout. The A1308 and A1309 provide an undervoltage lockout feature which ensures that the device outputs a VOUT signal only when VCC is above certain thresholds . The undervoltage lockout feature provides a hysteresis of operation to eliminate indeterminate output states. The output of the A1308 and A1309 is held low (GND) until VCC exceeds VUVLOHI . After VCC exceeds VUVLOHI , the device VOUT output is enabled, providing a ratiometric output voltage that is proportional...