nRF51 Series SoC

The nRF51 Series is a family of highly flexible, multi-protocol, system-on-chip (SoC) devices for ultra-low power wireless applications.

nRF51 Series devices support a range of protocol stacks including Bluetooth low energy (previously called Bluetooth Smart), ANT and proprietary 2.4GHz protocols such as Gazell. nRF51 Series devices are also on-air-compatible with existing nRF24L products from Nordic Semiconductor.
nRF51 Series logo_main_black

Protocol stacks - known as SoftDevices

The nRF51 Series are compatible with protocol stacks and associated SoC frameworks. These are known as SoftDevices and are available as binary file downloads from our website. This brings the key advantage that the very latest SoftDevice with associated features can be uploaded into members of the nRF51 Series SoC family of devices. This also introduces the possibility to upgrade application code and protocol stacks via Device Firmware Updates (DFU) in the field. A range of SoftDevices are available for different requirements.There are two devices in the nRF51 Series family of SoCs:

  • nRF514: ANT/Bluetooth low energy SoC
  • nRF518: Bluetooth low energy and 2.4GHz multi protocol SoC


SoftDevices currently available are:

  • S110: Bluetooth low energy single mode peripheral protocol stack
  • S120: Bluetooth low energy single mode master protocol stack offering 8 simultaneous connections
  • S130: Bluetooth low energy protocol stack, supporting multi-link central, peripheral, observer and broadcaster roles
  • S210: ANT 8 channel master and slave protocol stack
  • S310: Bluetooth low energy/ANT concurrent operation protocol stack


ARM® Cortex-M0
Flexible GPIO
Flexible Power Management
2.4GHz Multi-Protocol Radio


SoftDevice compatibility matrix

nRF51 Series SoC SoftDevices
S110 S120 S130 S210 S310
nRF51422 x x x x x
nRF51822 x x x    
nRF51824 x x x    


The nRF51 Series SoCs represent the next step forward in ultra-low power wireless SoCs in terms of integration, performance, flexibility and ease of wireless application development on SoCs with embedded protocol stacks. The device family is built around a 32-bit ARM® Cortex™ M0 processor core with variants that offer various memory and feature specifications to suit varying application requirements. The nRF51 Series introduces a brand new concept for developers using 2.4GHz ULP wireless SoCs by implementing a clean separation between application code development and protocol implementation. Application code for the nRF51 Series of devices is compiled/linked independently of the protocol stacks and can therefore easily be re-used across other variants in the nRF51 device family.


In addition to code compatibility, nRF51 Series devices with similar GPIO count will be pin compatible across the different product familes and across memory/feature variants. This means also means hardware (PCB layouts) can be reused without modification to provide ANT or Bluetooth low energy product versions as well as feature rich and entry level product alternatives. All digital IO alternatives like serial interfaces and PWM can be configured in software to use any GPIO pin on the nRF51 devices. This means that a single code base is a simple to port to applications with different PCB floor plans as well as to nRF51 devices with different pin counts.