| It can increase motor efficiency and reduce vibration.
| Removed when PWM slew rate exceeds 500V/µs
| Maintain measurement accuracy and reduce minimum duty cycle↓

Maxim Integrated announced on the 26th that it has launched the 'MAX40056', a bidirectional current-sense amplifier with built-in PWM (Pulse Width Modulation) noise rejection function.

Implementing a motor control system requires precise motor current sensing and winding current measurement. One method used for this purpose is to use a bridge circuit to measure ground or power as a reference point and then infer the winding current.

Direct measurement of winding current is simpler and more accurate, but is difficult to implement due to the high common-mode swing of the PWM signal. In addition, the PWM rejection performance of existing solutions is weak and the correction speed is slow, which limits the adoption of direct measurement methods.

The MAX40056 rejects PWM slew rates exceeding 500V/µs and completes correction within 500ns, providing complete winding current measurements with a 0.3% tolerance.

Patented PWM cancellation technology enables settling speeds four times faster than competitive products, enabling motor control designers to increase drive frequency or lower minimum duty cycles without compromising measurement accuracy.

Higher PWM frequencies improve current flow and reduce torque ripple, improving motor efficiency. Furthermore, precise winding current measurement at low duty cycles helps reduce or eliminate vibrations that occur when the motor is running at low speeds.

The MAX40056 has a wide common-mode voltage range of -0.1V to +65V and a protection range of -5V to 70V, preventing IC damage in the event of inductive kickback. Its bidirectional sensing capability makes it ideal for DC motor control, base stations, data centers, battery stacks, and many other applications that require accurate current measurement in noisy environments.

“Complex and sensitive systems like autonomous vehicles require accurate sensing feedback for advanced functionality and superior safety,” said Rahul Kumar, analyst at Allied Market Research. “The autonomous vehicle market is expected to grow to $556.67 billion by 2026, increasing the need for more precise motor control solutions.”

“The MAX40056 is ideal for applications that require high levels of accuracy and control by enabling PWM rejection and fast settling of current through the motor winding,” said Dimitry Goder, director of applications and product definition for the Core Products Group at Maxim Integrated. “Its unique design architecture opens up opportunities for performance enhancements and innovation in motor control applications.”