World’s smallest motor drivers boost battery runtime

Controlling the motors at the heart of devices like portable medical pumps and drivers, personal wellness devices, portable point-of-sale devices, miniature robots, surveillance equipment, precision tools and portable printers requires considerable engineering know-how. One of the biggest challenges is to combine logic and power components in a single chip on tight space and power budgets.

ST has now gathered all of these ingredients together in its line-up of tiny single-chip motor drivers that meet the needs of the most demanding portable and wearable applications. The combination of low power consumption, small form factor, and outstanding performance of ST’s new motor drivers is set to contribute to the widespread adoption of battery-powered IoT devices.

Measuring just 3x3mm, these devices are the world’s smallest single-chip motor drivers integrating all the functionalities to enable product designers to deliver compact, lightweight and user-friendly innovations into their target markets.

Frugal with battery energy, the drivers operate from a supply voltage as low as 1.8V and support power-saving design with ultra-low, best-in-class standby current of less than 80nA for a zero-power state when the motor is inactive. On the other hand, they can supply up to 1.3A_RMS to drive the motor and can therefore be used in a wide range of applications that include robotic positioning systems, printer motors, camera-autofocus mechanisms, toothbrush motors or syringe pumps.

The series currently comprises the STSPIN220 stepper-motor driver, STSPIN230 3-phase BLDC driver and STSPIN240 with two complete on-chip MOSFET bridges for driving two brushed DC motors. Another device designed to drive a single brushed DC motor with the current capability extended to 2.6A_RMS will go in production during Q3 2016. The power stage of each device features efficient integrated MOSFETs that minimise energy loss and heat dissipation. Despite their tiny size, there is no compromise in performance or function. The STSPIN220 can drive stepper motors with position resolution of 256 microsteps per step, enabling extremely smooth motion and fine positional accuracy.

In addition, all devices benefit from comprehensive built-in protection features including over-current, over-temperature and short-circuit protection. These ensure ruggedness and reliability, even in harsh industrial environments, without additional components thereby further reducing cost and complexity.

Domenico Arrigo, General Manager Industrial and Power Conversion Division, STMicroelectronics, commented: “Our latest STSPIN single-chip devices are proven to simplify precision motor control and cut time-to-market for new products. The ultra-low power consumption extends runtime in battery-operated applications and enables designers to enhance portable and mobile devices with high-added-value motorised functions.”

ST’s low-power, low-voltage STSPIN motor drivers are in production now, in 3x3mm QFN packages, priced from $0.75 for the STSPIN230 and STSPIN240 and $0.95 for the STSPIN220, in 1,000 unit quantities.