Motor efficiency can be improved and vibration reduced using the MAX40056 bi-directional current sense amplifier with patented pulse-width modulation (PWM) rejection, says the company. The high speed, wide-bandwidth amplifier rejects PWM slew rates of greater than 500V/µs and settles within 500ns to provide 0.3% accurate, full-scale winding current measurement.

The patented PWM rejection scheme achieves four times faster settling time than alternatives currently available, says Maxim. This enables motor control designers to increase drive frequency or decrease minimum duty cycle without sacrificing measurement accuracy. Higher PWM frequency smoothes out the current flow and reduces torque ripple. Accurate winding current measurement at low duty cycle helps reduce or can virtually eliminate vibration when the motor is running at a slow speed. The amplifier has a wide common mode voltage range of -0.1 to 65V and a protection range of -5.0 to 70V to protect the IC. Bi-directional sensing capability makes the amplifier suitable for DC motor control, basestation, data centre, battery stack and any applications which require precise current measurements in noisy environments.

The amplifier is available now and is supported by the MAX40056EVKIT evaluation kit.