Bi-directional current sense amplifier offers high accuracy and motor efficiency

02-07-2019 | Maxim | Power

Designers are now able to improve motor efficiency and decrease vibration using the MAX40056 bi-directional current sense amplifier with patented PWM rejection from Maxim Integrated Products.

The device 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 delivers four times faster settling time than competitive devices, enabling motor control designers to improve drive frequency or lower minimum duty cycle with no sacrifice to measurement accuracy. Higher PWM frequency levels out the current flow and diminishes torque ripple, following in more efficient motor operation. Accurate winding current measurement at low duty cycle assists to decrease or practically stop vibration when the motor is operating at a slow speed. The device has a broad common mode voltage range of -0.1V to +65V and a protection range of -5V to 70V to assure the inductive kickback does not damage the IC. With bi-directional sensing ability, it is excellent for DC motor control, datacentre, base station, battery stack and numerous other applications which need precise current measurements in noisy environments.

“Complex and highly sensitive systems such as self-driving and autonomous vehicles require extremely accurate sensing feedback to provide a high level of functionality and increased safety,” said Rahul Kumar, analyst at Allied Market Research. “The industry is ripe for a solution that can provide increasingly precise motor controls, especially with the expected autonomous vehicle market growth predicted to reach $556.67 billion by 2026.”

“MAX40056’s high PWM rejection and fast settling time obtains current measurements inline with the motor windings for highest accuracy and greatest control in sensitive applications,” said Dimitry Goder, director of applications and product definition for the Core Products Group at Maxim Integrated. “Its unique design architecture unlocks higher performance and future innovation in motor control applications.”

By Natasha Shek