8-bit Flash Microcontrollers Target Small Single-Phase DC Motor Control
LAPIS Semiconductor Co., Ltd., a ROHM Group Company, is introducing a family of 8-bit microcontrollers designed for single-phase dc motor control that supports a wide variety of applications. In many cases, no external components required, reducing board area and system costs. The ML610Q101 and ML610Q102 include peripherals and functions designed to control small single-phase dc motors with greater efficiency and lower noise compared with previous solutions. Optimized features enable precise control of the rotation and speed of single-phase fans and motors - using few external components - in electrically noisy environments, such as industrial equipment and computer systems.
An industry-leading high-accuracy internal oscillator and multiple timers are utilized to reduce rotational speed variations, minimizing audible noise. In addition, built-in hysteresis allows the differential comparator to monitor the Hall element on the motor to determine motor speed and direction, ensuring precise speed control. (Hall elements are less expensive and smaller than comparable Hall effect sensors.) Additional features include a compact 16pin package (4mmx4mm), making them suited for even the smallest fans, and high noise immunity (tested to ±30kV in IEC61000-4-2 noise testing) that enables support for applications with demanding environmental electrical noise requirements.
In response to market demands for smaller MCUs with high electrical noise immunity and precise rotational control, LAPIS Semiconductor has developed an integrated oscillator circuit and voltage regulator for the internal power supply that do not require external capacitors, resistors or crystals. The benefits include a two-fold improvement in oscillator accuracy compared with previous methods (industry-best) and reduced board space, since no external components are required. The high accuracy oscillator circuit allows for minimal rotational variations and precise speed when controlling single-phase fan motors, while six 8bit timers allow the software to provide quiet, high efficiency motor performance through soft switching control.
Also, careful circuit design and layout enable high noise immunity with few external components, making operation possible through ±30kV discharges - exceeding the Class 4 (+/-15kV) measurement limit, the highest class defined by the IEC61000-4-2 standard established by the IEC (International Electrotechnical Commission). This makes them suitable for use in industrial equipment, especially in applications exposed to high electrical noise environments such as motor control. To make evaluation easy ROHM offers a complete design and evaluation environment, which includes a ML610Q102 reference board along with software development and debug tools. Pricing is: ML610Q101-NNNMBZ0ATL $0.45 @ 10KU and ML610Q102-NNNMBZ0ATL $0.50 @ 10KU.
