Search Symmetry

  1. Home
  2. Symmetry Blog
  3. Video: An Overview of the Differences between the Nordic nRF51 and nRF52

Video: An Overview of the Differences between the Nordic nRF51 and nRF52

Stephanie Guimera in Blogs on August 07, 2015

About Stephanie Guimera

The Nordic nRF51-DK and nRF52 Preview DK are versatile development boards for Bluetooth® Smart, ANT, or 2.4GHz proprietary applications. The nRF52 introduces a number of new features and peripherals, bolstered by the addition of a Cortex M4F processor, which has been implemented with full debug and trace support.


Differences between the Nordic nRF51 and nRF5

Frequency band
2.4GHz ISM ( 2.40000 –2.4835GHz)
Frequency band
2.4GHz ISM (2.36000 –2.4835GHz)
On-air data rate
250 kbps, 1 Mbps or 2 Mbps
On-air data rate
1 Mbps or 2 Mbps

51822 : -93dBm for Bluetooth smart (-96dBm at 250kb -90dBm at 1Mbs -85dBm at 2Mbs)

51422 : -93dBm for Bluetooth smart, -90dBm ANT, -85dBm at 2Mbs, -30dBm whisper mode

-96dBm for Bluetooth smart, -92.5dBm at 1Mbs ANT, -89dBm at 2Mbs, -30dBm whisper mode
Radio current consumption LDO at 1.8V

-16mA –TX at +4dBM output power

-10.5mA –TX at 0dBm output power

-13mA –RX at 1Mbs

Radio current consumption LDO at 1.8V

-15.2mA –TX at +4dBM output power,

-10mA –TX at 0dBm output power,

-10.4mA –RX at 1Mbs

32-bit ARM Cortex M0
32-bit ARM Cortex M4F 
Program memory
256/128 KB Flash(40kB-180kB available for application development)
Program memory
512kB Flash (400 kB available for application development)
-16MHz crystal oscillator

-16MHz RC oscillator

-32kHz crystal oscillator

-32kHz RC oscillator (±250 ppm)


-32MHz crystal oscillator,

-64MHz RC oscillator,

-32kHz crystal oscillator,

-32kHz RC oscillator (±250 ppm)

16-channel PPI
Voltage regulator

LDO (1.8 to 3.6V),

LDO bypass (1.75 to 1.95V)

Buck DC/DC (2.1 to 3.6V)

Voltage regulator

-LDO (1.7 to 3.6V),

-Buck DC/DC (1.7 to 3.6V)

31 configurable
32 configurable
10-bit ADC, RNG, Temperature sensor, RTC
12-bit/200KSPS ADC, RNG, Temperature sensor
2 x 16 bit, 1 x 24bit, 2 x 24bit, RTC
5 x 32bit, 3 x 24bit RTC

New Features of the nRF52

  • General purpose comparator
  • Event Generator Unit (EGU)
  • A 2 kB direct mapped cache


Features Removed

  • UICR configuration options in the nRF52 Series:
    • RBPCONF - Replaced by APPROTECT
    • CLENR0 - Because the nRF51 style MPU is removed, this has been removed as well
    • XTALFREQ - 32 MHz crystal support only
    • FWID - Uses generic NRFFW registers
    • FICR configuration options in the nRF52 Series:
      • CLENR0 - Because the MPU has been removed, this has been removed as well
      • PPFC - Replaced by APPROTECT in UICR
      • OVERRIDEEN - Not needed
      • NRF_1MBIT[x] - Not needed
      • BLE_1MBIT[x] - Not needed


New Peripherals

  • Near Field Communication Tag (NFCT)
  • Pulse Density Modulation (PDM)
  • Inter-IC Sound (I2S)
  • Memory Watch Unit (MWU)
  • Pulse Width Modulation (PWM)


Additions and Improvements

  • The radio now offers TXPOWER modes configurable from +4 dBm to -40 dBm, support for Bluetooth Low Energy packet length extension, and Fast radio ramp-up time (40 µs)
  • An additional UART peripheral has been added
  • An additional RTC instance has been added
  • The ADC peripheral is replaced by a differential Successive Approximation Register Analog to Digital Converter (SAADC). The interface supports up to 4 differential inputs and EasyDMA for CPU offloading
  • All timers now support all bit modes (8, 16, 24, and 32 bits)
  • Set and Clear tasks have been added, and the number of tasks/events increased from 4 to 8
  • The number of PPI groups has increased from 4 to 6. A new type of endpoint called FORK can be used to trigger an additional task from a single event endpoint
  • New UICR configuration options in the nRF52 Series:
    • PSELRESET - Programmable reset pin that can be multiplexed to either GPIO or RESET
    • APPROTECT - Read-back protection mechanism



The nRF51 is still a solid option, especially for existing developments in which timing is crucial.


For more information about the nRF51, nRF52, and the associated development kits, call Symmetry at (310) 536-6190 or contact us online


Why partner with Symmetry Electronics? Symmetry's technical staff is specially trained by our suppliers to provide a comprehensive level of technical support. Our in-house Applications Engineers provide free design services to help customers early in the design cycle, providing solutions to save them time, money and frustration. Contact Symmetry for more information.


See all tags


Stay up to date with industry and supplier news!