Rugged MCUs optimized for rechargeable NiMH applications

August 25, 2016 // By Graham Prophet
From Lapis Semiconductor, a member of the Rohm group, the ML620130 family of 16bit low power MCUs is designed for compact industrial equipment requiring battery drive in noisy environments, and offers superior processing capability with low power consumption.

Low voltage drive contributes to greater energy efficiency and performance in compact battery-driven industrial equipment. In addition to exceeding the ±30 kV noise measurement limit, operating voltage has been reduced to 1.6V. Optimizing the operating voltage to an integral multiple of standard nickel metal hydride batteries ate end-of-charge cycle (NiMH, 0.8V× 2=1.6V) ensures efficient use without wasting battery charge. This contributes to decreased battery consumption, prolonging battery life in portables and battery-equipped industrial equipment. The ML620130 family consists of nine models offered in a variety of memory capacities, pin counts, and other characteristics.


The ML620130 family of ‘tough‘ MCUs incorporate multiple functions optimized for battery drive operation;

- Optimized for ultra-low-voltage rechargeable nickel metal hydride batteries.

The minimum operating voltage has been decreased, from the conventional 1.8V to 1.6V. This extends the supply voltage detection range down to 1.63V (typ.) – very close to the voltage of 2 nickel metal hydride batteries (0.8V×2=1.6V) – reducing the number of charge cycles and memory effects while prolonging battery life – allowing NiMH batteries to fully discharge before being cycled avoids, lapis asserts, any ‘memory’ effect.

- 16 MHz CPU and 32 MHz (PWM) peripheral clock operations increase performance 2-fold over Rohm’s standard lineup of ‘tough’ MCUs, while operating current is reduced by more than 25%.


- A high-accuracy on-chip oscillator eliminates the need for an external oscillator; the RC-type oscillator is built in (±1%@-20°C to ±85°C, ±1.5%@-40°C to +105°C). UART communication is enabled throughout the entire temperature range without an external oscillator, reducing peripheral component costs. In addition, both full-duplex (×1ch) and half-duplex (×2ch) modes are allowed, and in the event that bidirectional communication is not required at the same time the two receiving terminals and two transmission terminals can be flexibly assigned, making it possible to mount on smaller boards.


- High noise immunity inherited from Lapis Semiconductor’s conventional lineup of low-power MCUs makes it possible to surpass the ±30 kV Level 4 measurement limit (air discharge: ±15 kV) of the IEC61000-4-2 standard (electrostatic immunity testing standard). In addition, implementing circuit enhancements related to power lines and noise intrusion pathways resulted in a 30% improvement in noise resistance.


Rohm Semiconductor;


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