The A4990 is oneDual full-bridge drives, mainly used in automotive applications for stepper motors or small brushed DC motors. Each full bridge uses a DMOS power device with integrated freewheeling diodes. When switching between high-side drive and low-side drive, the control circuit prevents transconductance or breakdown.
The device can drive stepper motors in either direction at full current in each phase, enabling full-step operation with two phases on. It drives a DC motor in both directions and has a braking function. One input closes both bridges, allowing the motor to stop freely. All control modes can be easily implemented from the microcontroller's standard parallel interface using 3, 4, or 5 outputs.
Peak motor current can be limited by sense resistor selection, resulting in increased efficiency, reduced motor heat generation, and extended motor life.
The output is short-circuit protected against short-circuits to the power and ground wires, and includes low-load current sensing. Chip-level protection includes overtemperature shutdown and overvoltage and undervoltage lockout.
The A4990 is available in a 20-pin TSSOP power package with an exposed thermal pad (package type LP). Lead-free (Pb) package with 100% matte tin leadframe plating.
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Two full-bridge power outputs
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Typical application ± 800 mA, 28 V
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Adjustable peak current limit control
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1.4 A minimum overcurrent shutdown
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Continuous operation at high ambient temperatures
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Synchronous rectification to reduce power consumption
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Simple parallel interface control
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Reverse and non-reverse inputs
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No crossover current
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Low current consumption in sleep mode
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Error marker diagnostics
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Open load diagnostics for all outputs during the open-state process
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Output protection against overcurrent
- Over-temperature protection with hysteresis
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Overvoltage and undervoltage lockout
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3.3 V/5 V compatible input with hysteresis
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Thermally enhanced package (exposed pad)
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Fully integrated in a small TSSOP package for space-sensitive applications