超低功耗MCU，八仙过海
With the evolution of AI technology, intelligent terminals are becoming increasingly complex. As the core component connecting perception and execution and enabling terminal intelligence, MCUs are also becoming more and more specialized.
Ultra-low power consumption MCUs represent one such specialized market. These MCUs have extremely low power consumption, typically below the microampere level, and employ special designs and technologies to minimize power consumption and extend battery life. Additionally, ultra-low power consumption MCUs are highly integrated, capable of implementing multiple functions in a small package, thereby reducing system cost and complexity.
In recent years, the market for ultra-low power consumption MCUs has witnessed rapid growth. Its size is expected to increase from $5.12 billion in 2024 to $5.66 billion in 2025, with a compound annual growth rate of 10.6%. This growth is driven by the growing demand for energy-efficient solutions in various applications, especially in the fields of the Internet of Things (IoT), wearable devices, and smart home technologies. Moreover, the rise of edge computing is prompting manufacturers to adopt ultra-low power microcontrollers for local data processing, thus reducing latency and bandwidth requirements.
Since there is an opportunity in this niche market, major MCU manufacturers have taken action, striving to be the first to "reach the shore" in this emerging market through different technological approaches and products.
01 How to Achieve Ultra-Low Power Consumption?
Firstly, how to achieve ultra-low power consumption in MCUs is a question worthy of exploration.
To put it simply, efforts can be made in the following five aspects to reduce the power consumption of MCUs:
1. Process: The chip area of the MCU, the number of transistors, and the number of on-chip integrated and used analog functions/peripherals.
2. Power Supply Voltage: The current consumed in CMOS logic circuits is proportional to the square of the power supply voltage.
3. Clock Frequency: In applications that do not require high-speed processing, reducing the clock frequency can lower power consumption.
4. Peripherals: The more peripherals are activated or the more MCU functions are used, the higher the power consumption.
5. Operating Mode: Power consumption varies with different power consumption modes of the application.
To reduce power consumption in these aspects, various advanced technologies have emerged.
Ambiq's patented Subthreshold Power Optimization Technology (SPOT) allows its Apollo MCU to operate at a voltage of 0.5V, while other cutting-edge MCUs require 1.8V. The core principle of its SPOT technology lies in reducing the operating voltage of the CMOS circuits in the chip to the subthreshold voltage region (e.g., 0.3V). At this voltage, the CMOS is in an operating state where no conductive channel is formed, i.e., Vgs ≤ VT and surface potential ψs ≈ Fermi potential ψb. There is still a small current flowing through the device in a weak conduction state, known as the subthreshold current. Although the subthreshold current is small, the logic gates it drives can still perform logical operations, albeit at a slower speed. Meanwhile, it can still be well controlled by the gate voltage. Ambiq takes advantage of the characteristics of this region to significantly reduce power consumption.
TSMC's Ultra-Low Power Technology (ULP) offers ultra-low leakage devices (ULL), ultra-low SRAM, and low operating voltage solutions. The ULP technology includes 40nm ULP (40ULP), 22nm ULL (22ULL), and FinFET technology. Among them, the ULP process focuses on dynamic power consumption optimization through voltage regulation and process scaling (e.g., the 22ULP process reduces the area by 10% compared to the 28HPC process, improves performance by 30%, or reduces power consumption by 30%), making it suitable for scenarios sensitive to computational energy efficiency ratios. The ULL process emphasizes static leakage control, reducing standby power consumption through transistor structure optimization and extending battery life, which is suitable for devices with long standby times or intermittent operation.
NXP's Adaptive Dynamic Voltage Control System (ADVC) features a dual-domain architecture that combines real-time processing and ultra-low power sensing functions in a single device. This processing architecture consists of an Arm Cortex-M33 real-time domain and an Arm Cortex-M0+ ULP always-on sensing domain. The M33 core in the real-time domain operates at a frequency of up to 96MHz, with a current consumption characteristic of 24μA/MHz. The real-time core implements the Armv8-M Baseline ISA using SIMD DSP instructions and a floating-point unit, enabling fast and efficient on-demand processing of data acquired from the ULP domain for transmission via wired/wireless networks or recording to a storage mechanism. The M0+ core is designed for always-on operation, using a combination of low-power analog and digital peripherals in the always-on domain to collect sensor data. For example, the ULP sensing subsystem consumes only 14μA when operating at 2MHz while performing a 100kbit/s I2C task. It offers seven low-power modes, achieving sub-μA level power consumption in the deepest sleep mode.
Dutch company Innatera has launched the world's first commercially available Neuromorphic Microcontroller, which can reduce latency to one-hundredth of that of traditional processors and consume only one-five-hundredth of the power in artificial intelligence applications. Neuromorphic devices mimic the way the brain works in several aspects. For instance, traditional microchips use a fixed rhythm clock signal to coordinate circuit actions, while neuromorphic architectures often operate through "pulses," generating an output only after receiving sufficient input signals within a certain period. With a power consumption below the milliwatt level, this microcontroller can continuously process sensor data, even in devices with extremely limited power. For example, it can achieve radar-based presence detection with a power consumption of only 600 microwatts or audio scene classification with 400 microwatts. In contrast, systems using traditional electronic technologies to achieve similar functions typically require 10 to 100 milliwatts of power.
02 The Intense Competition in the Ultra-Low Power Consumption MCU Market
Currently, low power consumption is just the basic requirement for ultra-low power consumption MCUs in the market. The goal of major MCU manufacturers is to maintain high performance and small size while achieving low power consumption, and even to support AI functions.
In June 2025, Renesas Electronics launched the RA2L2 series of ultra-low power consumption MCUs. The new products are based on the Arm Cortex-M23 core, support the new specification of USB-C 2.4, and have been optimized for voltage detection sensitivity. They are equipped with 64KB - 128KB of on-board flash memory, 16KB of SRAM, and 4KB of data flash memory. The rich peripherals include USB-C, CAN, I3C, SPI, low-power UART, ADC, etc., supporting an active power consumption of 87.5μA/MHz and a soft standby current of 250nA. Renesas provides a full set of FSP software support packages for ecosystem development, facilitating IP migration and design replacement, and improving project development efficiency and system integration.
STMicroelectronics has introduced the ultra-low power STM32 U3 series, which uses an Arm Cortex-M33 core with a main frequency of 96MHz and has an energy efficiency score of 117 Coremark/mW, twice that of the previous generation products. The core of this series is the near-threshold voltage technology, which reduces the dynamic power consumption to 10µA/MHz and the static power consumption to 1.6µA. During manufacturing, AI-assisted adaptive voltage regulation is used for optimization. This series is configured with up to 1MB of dual flash memory and 256KB of SRAM. In terms of security, a new key library has been added based on the STM32U5, and the Coupled Chain Bridge (CCB) technology is used for the first time to protect pre-installed factory keys. The product line offers options with or without a hardware encryption accelerator and integrates new peripheral interfaces such as I3C, supporting an industrial temperature grade of up to 105°C.
Texas Instruments' MSPM0 C1104 MCU is based on the Arm Cortex-M0+ core, uses a 65nm process technology and a wafer chip-scale package (WCSP), with a size of only 1.38mm², approximately the size of a black pepper grain, which is 38% smaller than current similar products in the industry. It is equipped with 16KB of memory, a 12-bit analog-to-digital SAR data converter with three channels and six general-purpose input/output pins, and provides standard communication interfaces for UART, SPI, and I²C. Its operating power consumption is only 87μA/MHz, and the standby power consumption is as low as 5μA, supporting SRAM data retention. Additionally, the MCU has a built-in buzzer function, further simplifying the peripheral circuit design and providing higher integration and lower development costs for device manufacturers.
Not only are foreign giants intensively competing, but domestic MCU manufacturers are also not far behind.
In April 2025, Xiaohua Semiconductor released the HC32L021 series, which is based on the Arm Cortex-M0+ core with a main frequency of 48MHz. It is configured with 64KB of Flash and 6KB of SRAM and is equipped with a high-precision RC48M internal clock. It supports a rich range of interface resources (low-power UART, SPI, I2C, 1Msps sampling ADC, full set of timers/RTC, etc.) and can operate stably in a wide voltage range of 1.8 - 5.5V and a wide temperature range of -40°C - 105°C. The static power consumption can be reduced to a minimum of 0.65μA, and the dynamic power consumption is better than that of similar products, making it attractive for battery life and the mobile device market.
GigaDevice's GD32L235 series uses an Arm Cortex-M23 core with a maximum main frequency of 64MHz. It employs an ultra-low power process technology to reduce power consumption at the hardware level and supports six low-power modes, including deep sleep, partial sleep, and standby. In the deep sleep mode, the current drops to 1.8uA, and the wake-up time is less than 2uS. In the standby mode, the current is as low as 0.26uA. Even in the full-speed operation mode at the maximum main frequency, its power consumption is only 66uA/MHz, achieving an excellent balance between performance and power consumption.
03 Low Power Consumption, High Market Interest
The Business Research Company predicts that the market for ultra-low power microcontrollers will continue to grow strongly in the coming years. It is estimated that by 2029, the market size of ultra-low power microcontrollers will reach $8.37 billion, with a compound annual growth rate of 10.3%.
Ultra-low power consumption MCUs have a wide range of applications, including automotive electronics, smart homes, medical devices, and wearable devices.
In the automotive industry, ultra-low power consumption MCUs can be applied to in-vehicle motors, capacitive touchscreens, infotainment systems, steering systems, and headlights, as they can improve fuel efficiency and extend battery life. Additionally, these flexible devices are designed to reduce the leakage power domain of standard batteries and feature high security, low noise, low latency, and multiple communication functions, thereby enhancing product quality standards. With the increasing R & D investment in supporting smart portable battery-powered devices, the market share of ultra-low power microcontrollers will increase significantly in the coming years.
Ultra-low power consumption MCUs are the key technology for achieving energy efficiency in smart homes. They play important roles in three major areas: sensor nodes, smart lighting, and smart security. In sensor nodes, ultra-low power consumption MCUs ensure long-term device operation and effective collection of environmental data. Smart lighting systems take advantage of their low power consumption characteristics to significantly reduce energy consumption while controlling lights and support intelligent functions such as timing and scene linkage. In terms of smart security, ultra-low power consumption MCUs are applied to devices such as door magnets and smoke detectors, providing long-lasting home security protection.
Medical electronic terminal devices have extremely high requirements for MCUs, among which low power consumption is an important factor. Ultra-low power consumption MCU chips are suitable for portable medical devices, where "portable" usually means the devices are battery-powered. Typically, new functions added to these devices will increase power consumption. However, when designing portable medical devices, developers cannot require end-users to use large and heavy batteries or replace batteries frequently. Ultra-low power consumption MCU chips can ensure long-term device operation and continuous provision of stable health monitoring services.
Overall, with the trend of increasing complexity of intelligent terminals, the market for ultra-low power consumption MCUs is accelerating technological iteration and scenario implementation. Domestic and foreign manufacturers are not only competing in terms of power consumption but also in performance, size, and price. In this process, factors such as R & D strength, business acumen, and the impetus of the macro - environment are all indispensable.
However, once the wind starts to blow, it won't stop. A new market is emerging, and it is foreseeable that lower power consumption will take us further.
This article is from the WeChat official account "Semiconductor Industry Insights" (ID: ICViews), author: Junxi, published by 36Kr with authorization.