Unveiling Ultra-Low Power Operations in NXP's KL3x MCU Family

By Saumitra Jagdale

Freelance Technology Writer

September 28, 2021


Unveiling Ultra-Low Power Operations in NXP's KL3x MCU Family

With IoT and embedded system technology gaining momentum with time, it is necessary for the microcontrollers and other devices to be energy efficient and consume low power. This ensures the optimum performance of the applications and effectively aids in reducing the size of the end products, as it would require smaller powering units. Hence, low power MCUs like the KL3x series prove to be of immense help in developing sophisticated applications with high precision.   

The NXP Semiconductors brings you the ultra-low-power series of efficient microcontroller units (MCUs) with a small form factor, making them extremely easy to integrate with a wide range of sensors like the Kinetis KL3x series. This makes the Kinetis KL3x family of MCU boards the best choice for compact and sophisticated applications like blood glucose monitoring devices, electronic scales, flow meters, and many more. The onboard segment LCD controller gives the KL3x series an edge over its predecessors, making LCD interfacing extremely easy.  



Credits: element14

Energy Efficiency of KL3x Family of MCUs

The Kinetis L series microcontrollers (MCUs) combine the ultra-low-power operation with energy efficiency and ease of the ARM Cortex-M0+ processor. The Kinetis ultra-low power L series is also compatible with the Kinetis K series that operate on ARM Cortex-M4 based processors, providing better performance and flexibility. Apart from their low power consumption, they also offer a small form factor making them a suitable choice for various embedded system applications. They can be easily programmed with the Freescale Kinetis Design Studio IDE, a no-cost Integrated Development Environment (IDE) for the Kinetis MCUs, or through numerous other software like ARM Keil MDK, Atollic TrueSTUDIO, Green Hills Software MULTI, and a few more.


The Kinetis KL3x ultra-low-power family of MCUs provides a segment LCD controller in addition to the Kinetis KL1x series. The KL3x MCU family is also compatible with the ARM Cortex-M4 based Kinetis K30 family, along with a few others like the KL1x, KL2x, and KL4x series of MCUs. Thus, providing feature integration and a migration path to lower or higher performance. They come with a rich suite of analog, communication, timing, and control peripherals for numerous applications.


Credits: NXP Semiconductors

Architectural Block Diagram of the KL3x Family 

The MCU series works on an ARM Cortex-M0+ processor that operates at a  frequency of 48 MHz over a wide range of temperatures (-40 C to +105 C). It can operate in multiple, flexible low power modes including a new compute mode that reduces the power consumption by putting the peripherals into an asynchronous stop mode. It also offers a bit manipulation engine for improved bit handling of the peripheral modules. Moreover, it offers a DMA up to four channels for peripheral and memory maintenance, resulting in lower CPU burden and quicker system throughput.

The KL3x family also offers up to 16-bit ADC and a 12-bit DAC with DMA support. Additionally, a highly accurate internal voltage reference of 1.2V is also available. 

Coming to the timing and control features, it provides one 6-channel and two 16- bit low power PWM (Pulse Width Modulation) modules for simulating analog voltages. Also, 2-channel, 32-bit periodic interrupt timer along with the low-power timer allows operation in all power modes (except VLLS0). A secure real-time clock is also available. 

Credits: NXP Semiconductors

The MCU family offers a variety of communication interfaces for easy connectivity with other devices. The LPUART, SPI, I2 C, FlexIO, ADC, DAC, LP timer, and DMA support low power mode operation without waking up the core. Hence, drastically reducing energy consumption. It offers two I2C peripherals with DMA support, up to 1Mbps, and is compatible with SMBus V2 features, three UART peripherals with two LPUART and a DMA support, and two SPI peripherals with DMA support. 

One of the key features of the KL3x series is the flexible, low-power segment LCD controller that offers up to 376 segments (i.e. 51 x 8/55 x 4). LCD blink mode allows for a low average power consumption while staying in low-power mode. Segment fail detection notifies the user of display failures, reducing the risk of an incorrect readout in medical applications. Reassigning the front plane and backplane allows for more pin-out flexibility, making PCB design easier and allowing for LCD configuration changes via firmware without having to rework the hardware. Other GPIO functions can be assigned to unused LCD pins. Additionally, as an optional feature, it also provides a low-power capacitive touch-sensing interface. 


The KL3x series of ultra-low-power MCUs working on a 48 MHz ARM Cortex-M0+ processor consumes very little power and can operate over a wide range of temperatures ranging from -40 C to +105 C. It provides a segment LCD controller, which gives it an edge over the other Kinetis MCU families. It provides a wide range of analog peripherals including 12-bit DAC and 16-bit ADC, along with a sufficient number of GPIO peripherals. Moreover, it offers a variety of communication options like I2C, SPI, low-power UART that makes communication with other devices very convenient. 

With its, small form factor and low power consumption, it suits best for applications like blood glucose meters, electronic scales, flow meters, smart meters, and thermostats. The segment LCD controller also adds a helping hand to these applications, making the interfacing of LCD displays very convenient. 

You can head over to the product page for more information.

Saumitra Jagdale is a Backend Developer, Freelance Technical Author, Global AI Ambassador (SwissCognitive), Open-source Contributor in Python projects, Leader of Tensorflow Community India, and Passionate AI/ML Enthusiast.

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