NXP Semiconductors – Dual-core LPC5411x MCU offers voice-detection capability in hardware



The LPC5411x microcontrollers from NXP Semiconductors offer a valuable combination of high peak processing capability and ultra-low power consumption for always-on sensing applications.

A dedicated on-chip digital microphone sub-system reduces the power used for sound-input and -processing functions, making the LPC5411x particularly useful for voice-triggering applications in end-products such as toys and home-automation equipment.

The LPC5411x parts contain a 100MHz ARM® Cortex®-M4 main processor core and an ultra-low power ARM Cortex-M0+ co-processor. The co-processor is an energy-efficient and easy-to-use 32-bit core which is code- and tool-compatible with the ARM Cortex-M4 core. The co-processor runs at up to 100MHz, offering a simple instruction set and reduced code size.

As well as the two processor cores, the MCUs feature a wide choice of serial peripherals, some of which perform autonomous operations, allowing the main processor to enter a power-down mode to save energy while retaining always-on sensing capability.

The LPC5411x parts include up to 192kbytes of SRAM as well as 256kbytes of Flash. This memory provision offers the potential to run applications from SRAM for reduced power consumption.

The digital microphone sub-system features a dual-channel PDM microphone interface, hardware voice activity detection, and the option to stream the processed output data to an I2S bus.

The MCU also has a Full-Speed USB device interface with crystal-less operation, a selection of timers and eight flexible serial communication peripherals, each of which can be a USART, SPI or I²C interface.


  • 20-channel DMA controller
  • 12-channel, 12-bit ADC operating at up to 5Msamples/s
  • Temperature sensor
  • Programmable power-management unit
  • Sleep, deep-sleep, and deep power-down modes
  • Single 1.62V to 3.6V power supply
  • 128-bit unique device serial number for identification


  • Wearable devices
  • Toys and games
  • Smart home devices
  • Robotics
  • Drones
  • Asset-tracking equipment
  • Building automation

The LPC54114 Audio and Voice Recognition Kit provides a complete hardware and software platform for developers to implement an always-on, low-power voice triggering product. It consists of an LPCXpresso54114 board, a shield featuring a digital microphone, audio codec and a monochrome OLED display, and a USB cable.

Orderable Part Number: OM13090