The semiconductor manufacturer STMicroelectronics claims to have developed the first single-chip controller for two-phase stepper motors which, it says, will result in quieter, smaller, lighter, simpler and more efficient precision motion and positioning systems.

According to ST, rival products need special motor-control software and multiple chips, which designers must combine before developing their applications. It adds that the small size and low weight of its single chips will lead to lower-cost, more responsive equipment. System efficiency will also be improved by eliminating the need for power-dissipating shunt resistors.

The ST chips (above) need no software and simplify system design by performing all calculation, control and interfacing functions on-board. They allow precise control over rotational speed, and are said to result in smooth, noiseless motor operation.

On-chip gate-driver circuitry for motor power stages can operate from 8–85V, supporting applications with power ratings up to 300W. The motion engine is optimised to avoid motor resonance. Various forms of protection are built in.

ST is already working with customers to design the cSpin chips into equipment such as robotic systems, and positioning and rotation equipment.

The first two versions support micro-stepping at resolutions of up to 1/128 steps, and incorporate a predictive control algorithm and an auto-adaptive decay mode. They cost $3 each in quantities of 1,000.