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  3. A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection

A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection

A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection

A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection

Product catalog summary
Overview: The A1444 and A1445 are integrated circuits designed for low-voltage brushless DC motors, featuring a Hall element, full-bridge output driver, and PWM speed control logic. They are ideal for applications like cellular phones and handheld devices that require rotor speed control and quick start-stop cycles.
Specifications: The devices operate within a voltage range of 1.8 to 4.2 V, with a forward supply voltage of 5.0 V and reverse supply voltage of -5.0 V. They support a continuous output current of ±250 mA and a peak output current of ±500 mA, functioning effectively between -40 to 85 ºC, with a maximum junction temperature of 165 ºC.
Features: Key features include externally controlled motor speed regulation, fast startup and braking, reverse voltage protection, output short circuit and thermal shutdown protection, soft switching for noise reduction, unidirectional mode, chopper stabilization, sleep mode for power saving, and an antistall feature for continuous rotation.
Functional Description: The soft switching feature minimizes noise and EMI by controlling the output switching slew rate. The SLEEP pin facilitates braking and sleep mode to conserve power. The antistall algorithm restarts the motor if a stall occurs, and PWM signals regulate motor speed with a user-selectable duty cycle via the PDC pin.
Application Information: The document includes application circuits for user-controlled sleep/enable mode and simultaneous control of power supply and sleep mode. No external diode is needed for reverse battery protection, and thermal shutdown protects against output shorts.
Power Derating: To prevent exceeding the maximum junction temperature, power derating or improved heat dissipation is necessary. Formulas are provided to estimate junction temperature based on power dissipation and thermal resistance.
Disclaimer and Usage Caution: Allegro MicroSystems advises verifying the currency of the information before ordering. Their products are not intended for life support devices where failure could impact safety. Allegro assumes no responsibility for use or patent infringements.
Package Specifications: Specifications for the Package EW, 6-Pin MLP/DFN are provided, focusing on seating plane and terminal configurations. Dimensions are nominal and not for tooling use, with exact configurations at the supplier's discretion within specified limits.
PCB Layout Recommendations: A reference land pattern layout based on IPC7351 standards is provided. It is recommended to maintain a minimum distance of 0.20 mm between pads, with adjustments for application processes and PCB layout tolerances. For multilayer PCBs, thermal vias at the exposed thermal pad land can enhance thermal dissipation, referencing EIA/JEDEC Standard JESD51-5.
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Catalog excerpts

A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection-1

VDD Reverse Battery Output Full Bridge Q1Q3Q2Q4 SLEEP Power and SleepMode Control Active BrakingControl Drive LogicandSoft SwitchingControl GND VOUT1 Stall Detection 0.1 F VOUT2 AmHallElementp M Thermal ShutdownProtection PDC > ESD PWMControl >

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A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection-3

CharacteristicsSymbolTest ConditionsMin.Typ. > 1 Max.Unit Supply Voltage V > DD T > J < T > J (max) 2.0 4.2 V Extended Supply Voltage > 2 V > DDE T > J < T > J (max) 1.8 ֖4.2 V Supply Current I > IN >V > INHI , T > A = 25C, no load Ж4 6 mA V > DD(ON) V > IN < V > INLO , T > A = 25C Ж10 A Total Output On-Resistance I > OUT = 50 mA, V > DD = 2 V, T > A = 25ְC 3.9 ֖I > 3 R > DS(on) OUT = 50 mA, V > DD = 3 V, T > A = 25C Ж2.6 I > OUT = 50 mA, V > DD = 4 V, T > A = 25ְC 2.2 ֖ Reverse Battery CurrentI V > RDD = 4.2 V, current flowing out of VDD pin, T > RDD A = 25ְC ֖10 mA ֯S ϯL ϯE ϯE ϯP Input Threshold...

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A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection-4

CharacteristicsSymbolTest ConditionsMin.Typ. > 1 Max.Unit > OP 2 V V > DD 4 V35 75 G B Magnetic SwitchpointsB > RP 2 V V > DD 4 V֖75 35 ֖G B > HYS 2 V V > DD 4 V70 ֖G Output Polarity VOUT1B < B > RP LOW֖VB > B > OP HIGH֖VVOUT2B < B > RP HIGH ֖VB > B > OP LOW֖V > 1 Typical data are for initial design estimations only, and assume optimum manufacturing and application conditions, such as T > A = 25C. Performance may vary for individual units, within the specified maximum and minimum limits. > 2 Device operates with lower supply voltages, down to 1.8 V, with slight variation in specification of magnetic...

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A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection-5

Device Start-up The start-up behavior of the device output is determined by the applied magnetic field, as specified in the Electrical Characteris- tics table. Speed Control > When the rate of rotation exceeds the specified threshold, S > Antistall Algorithm Soft Switching Braking and Sleep Mode If a stall condition occurs, the device will execute an antistall algorithm to restart the motor. The A1444 and A1445 devices include a soft switching algorithm that controls the output switching slew rate for both output pins. As a result, the devices are ideal for use in applications requiring low audible...

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A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection-6

Allegro MicroSystems, Inc.115 Northeast CutoffWorcester, Massachusetts 01615-0036 U.S.A.1.508.853.5000; www.allegromicro.com >

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A1444 and A1445 Low-Voltage Full-Bridge Brushless DC Motor Driver with Hall Commutation, Externally Controlled Speed Regulation, Soft Switching, and Reverse Battery, Short Circuit, and Thermal Shutdown Protection-7

The device must be operated below the maximum junction tem-perature of the device, T > J (max). Under certain combinations of peak conditions, reliable operation may require derating supplied power or improving the heat dissipation properties of the appli- cation. This section presents a procedure for correlating factors affecting operating T > A = 25C, V > DD = 3 V, I > DD = 85 mA, V > LOAD = 2.43 V, I > LOAD = 83 mA, and R > JA = 250 аC/W, then: P > J . (Thermal data is also available on the Allegro MicroSystems website.)The package thermal resistance, R > D = V > DD I > DD ז V > LOAD I > LOAD...

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*Prices are pre-tax. They exclude delivery charges and customs duties and do not include additional charges for installation or activation options. Prices are indicative only and may vary by country, with changes to the cost of raw materials and exchange rates.