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About the nRF51 Series

The new multi-protocol 2.4GHz radio provides an unprecedented combination of high-performance, ultra low power consumption, and flexibility.


The new multi-protocol 2.4GHz radio provides an unprecedented combination of high-performance, ultra low power consumption, and flexibility. Key features and benefits of the radio include:

  • -92.5dB RX sensitivity in Bluetooth low energy mode;
  • Up to +4dBm output power in all modes;
  • Up to 9.5dBm improvement in link budget compared to Nordic’s previous generation radio;
  • Sub-10mA peak currents running off a 3V coin cell battery;
  • Bluetooth low energy (Bluetooth v4.0) compliant;
  • 100% on air compatibility with Nordic's existing nRF24L series ICs;
  • Support for non-concurrent and concurrent operation of a range of protocols including ANT, Bluetooth low energy, and proprietary 2.4GHz RF;
  • Full range received signal strength indication (RSSI).


The nRF51 series SoC architecture is designed specifically to minimize average current consumption and enable single chip implementations of a wide range of wireless applications. Key features and benefits of the architecture include:

  • Powerful, low power consumption 32-bit ARM® Cortex™ M0 processor with 2µs start-up time that minimizes active time and improves code density compared to a 8/16-bit processor;
  • Advanced and fine-grained power management scheme. Individual system blocks can be powered on or off independently and control their clock autonomously based on activity level;
  • Programmable Peripheral Interconnect (PPI) system. Enables peripherals such as radio, timers’ and I/O to interact autonomously with each other without involving the processor. Saves power by minimizing processor active time and at the same time relaxes real time requirements for the processor;
  • Highly efficient EasyDMA radio interface with flexible RAM mapped FIFOs;
  • Flexible GPIO mapping eases PCB design and helps minimize the number of routing layers;
  • Custom 2-region Memory Protection Unit (MPU) enabling program memory and run-time protection of pre-compiled protocol stacks such as ANT and Bluetooth low energy.


The nRF51 series software architecture features a unique and powerful separation between protocol stack and user application code providing application developers maximum flexibility, ease-of-development, and code safety.

  • Protocol stacks, for example ANT or Bluetooth low energy, are delivered as a pre-compiled binary or pre-programmed on devices;
  • Stacks are 100% asynchronous and event driven and provide thread-safe Supervisor Call (SVC) based application program interfaces (API) to the application layer;
  • Very simple programming model, no proprietary application framework or scheduler/RTOS dependencies, ease and accelerate code development;
  • Protocol stack and application code have no link time dependencies and can be compiled and updated/programmed separately;
  • Stacks are fully run-time protected ensuring interoperability and reducing the risk of application bugs affecting stack operation;
  • Stacks are delivered as verified and qualified binary objects.

All nRF51 Series ICs are code-compatible and groups of ICs will be pin-compatible enabling developers to keep and maintain a single code base that can be used and re-used across a range of different projects. Pin compatible ICs enable developers to both re-use hardware designs for different projects and migrate easily from one IC to another during development, prototyping, and production.

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