Renesas Electronics is expanding its safety and efficiency support for home appliances and tools with the innovative RL78/G1G Group of microcontrollers (MCUs). In complement to its current brushless DC motor control (BLDC) MCU offerings, Renesas delivers power-efficient performance with shorter development time and up to 40 percent lower system costs, in a small but powerful single-chip solution for appliances like advanced electric fans, electric tools, and food processors, and many other applications that require fine motor control.
Development based on a common platform supporting all product levels, from multifunction high-end to entry-level models, has become the mainstream for small electric appliances incorporating BLDC motors. By using Renesas’ existing RL78/G14 Group in their high-end products, customers can utilize the same software resources in products at all price points, from high-end to entry-level models. In addition, integrating the external components onto one chip and extending the built-in, low-capacity flash memory lineup enables designers to reduce system cost by 40 percent compared with previous devices for BLDC motor control in these small appliances and consumer products – a significant cost savings for these competitive markets.
(1) On-chip PGA with software gain setting for amplifying very small signals
The RL78/G1G Group integrates an amplifier that supports setting the amplification factor for very small signals by using software. This eliminates the need to add an external amplifier for inverter circuit fault detection during BLDC motor control.
(2) On-chip high-speed comparator with response time 1/8 that of earlier products for more accurate fault detection. The RL78/G1G Group’s integrated high-speed two-channel comparator has a response time of 0.15 µs (max.), 1/8 that of comparable earlier Renesas products. This eliminates the need for an external comparator and makes it possible to reduce the size of the wiring board. The PGA output signal can be selected by the comparator, making it possible to use it as an overvoltage protection device for the inverter circuit during brushless motor control. For example, in a food processor malfunction in the brushless DC motor control can be detected immediately so that the motor can stop safely.
(3) Backward compatibility with earlier products, allowing reuse of existing software and shorter turnaround time (TAT)
The RL78/G1G Group preserves compatibility with the motor control–related peripheral functions integrated into the earlier RL78/G14 Group and includes an on-chip timer RD optimized for brushless motor control. This allows for wide-ranging scalability in combination with the RL78/G14 Group. A single platform can be used to develop products ranging from the high-end to the popularly priced, and the ability to reuse existing software helps shorten the time required for development.
The new RL78/G1G Group comprises six product versions with package pin counts of 30, 32, or 44 pins, and on-chip flash memory capacity of 8 or 16 kilobytes (KB). Sample of Renesas Electronics' new RL78/G1G MCUs are available now. Mass production is scheduled to begin in December 2014 and is expected to reach a combined volume of 500,000 units per month in 2015.