In addition to low power consumption, the new lineup offers high-performance on-chip oscillators, built-in circuits for sensor functions and extended system operating time.
By optimizing their power management circuitry, NEC Electronics has reduced standby power consumption in these new devices (when only the real-time clock functions are operational) by 60 percent, from an average of 2.4 microamperes (uA) to 1.0 uA. Likewise, power consumption at 10 MHz operation has been reduced by 10 percent from 3,9 to 3,5 milliamperes (mA), and at 20 MHz operation by 20%, from 8,2 to 6,5 mA. This lowered power consumption contributes to higher overall performance in end systems, a necessity for designers of the latest battery-driven applications. The new MCUs also offer the industry’s highest power/performance ratio, moving the bar from 1.8 to 1.5 milliwatts (mW) per million instructions per second (Dhrystone 1.1).
Three on-chip oscillator circuits are able to generate three separate operating frequencies, one at the power-saving clock speed of 1 MHz, another at the high-performance clock speed of 20 MHz and a third at the conventional clock speed of 8 MHz, allowing users to select the most optimal operating frequency for a given application. An error rate of guarantee 1 percent at operating frequencies of 8 and 20 MHz eliminates the need to add an external oscillator for asynchronous data transfers, which demand high performance. This also contributes to lower costs and smaller sizes in end systems.
An optimized 12-channel, 10-bit A/D converter circuit improves the time it takes to convert analog input into digital output, thereby reducing signal conversion time from 6 to 3 microseconds — 50 percent faster than conventional products. Further, the addition of one internal operational amplifier channel and two internal comparator channels, in lieu of externally mounted peripherals, allows a wide range of analog data to be measured at low cost.
The 78K0R Kx3-L MCUs also include a built-in dedicated booster circuit that reduces operating voltage during flash programming from 2.7 to 1.8 volts (V) and extends operating time in the end system.
As environmental awareness has grown, energy-saving systems have become particularly reliant on MCU technology. Over the past several years, NEC Electronics has delivered many ultra-low-power 8- and 32-bit MCUs that have met the demand for energy efficiency. With the introduction of the new 78K0R/Kx3-L devices, NEC Electronics is now delivering the benefits of energy efficiency in its 16-bit products.