ON Semiconductor - Miniature Integrated Driver ICs with High Current Capability that Reduce Space in Stepper Motor Designs

Designed for use with two-phase stepper motors and a host microcontroller, the AMIS-30542 mixed-signal motor driver ICs provide high-accuracy and reliable motor control and deliver maximum current outputs of 2.2 ampere (A) continuous and 5.0 A peak. Each device integrates smart motor control capability with voltage regulation, on-board current sensing and a number of protection and diagnostic functions. This level of integration eliminates the need for external switches and sense resistors. The on- board speed and load angle feedback allows removing expensive end of line switches and hall sensors on applications ranging from surveillance cameras, robotics to printers, industrial automation equipment and textile machines.

The new ICs feature two embedded H-bridges and connect to a host microcontroller via an SPI interface and dedicated I/O pins. Each chip provides speed and load-angle output, which allows for the accurate control of motor torque and speed as well as the creation of stall detection algorithms. Seven step modes can be configured, from full step to 32 micro-steps. An on-chip current translator is used to calculate the appropriate PWM current based on the clock signal at the ‘NXT’ input pin and the status of the Direction (DIR) register or input pin. The PWM current control includes automatic selection of fast and slow decay modes.

Both the AMIS-30532 and AMIS-30542 are compatible with 5 volt (V) and 3.3 V microcontrollers. The integrated voltage regulator can be used to provide microcontroller power, thus minimizing further the need for external components. Each device also incorporates a microcontroller reset function and an integrated watchdog function. Thermal warning and shutdown functionality and full output protection and diagnosis capabilities are also provided.

“Combining high-accuracy speed and torque control with higher integrated current capability is addressing a broader range of motors and emerging applications while saving space and reducing component count,” said Guido Remmerie, director motion control and energy management products at ON Semiconductor. “Combining industry-leading levels of integration with ultra-miniature NQFP packaging, the AMIS-30532 and AMIS-30542 address these criteria at the same time as providing the reliability required for demanding applications such as those in the industrial and automotive arenas.”