Memory solutions from EXASCEND +++ High-speed and ultra-low-power 8-bit MCU with up to 50 MHz +++ Real Time Clocks - precise billing of charging stations

Three "busy bees" operate at up to 50 MHz:
High-speed and ultra-low-power 8-bit MCU

High-Speed and Ultra-Low-Power 8-Bit MCU

The "Busy Bee" family from SILICON LABS has grown.
No less than 3 hard-working female workers are making a decisive contribution to the field of "smaller is always better MCUs" on the basis of an 8-bit.

With the 5th generation of the "Busy Bee 5" (EFM8BB5 for short), the manufacturer has made a great leap in the direction of power reduction at a maximum operating frequency of up to 50 MHz.

Solution for smart applications
The three bees BB52, BB51 and BB50 come from the same hive, but cover different needs. They are similar in core, speed, timer and 12-bit ADC structure. Similar to a bee colony, they develop their strengths in handling different tasks. They differ in flash, RAM, comparators and the DAC unit.

Getting a lot done on her own

Similar to a biological honey collector, every busy bee can "manage" a lot on its own. Its size and manoeuvrability play the decisive role here. The degree of integration provided is very high and economical at the same time.

With the "Busy Bee" BB5, external oscillators and an external charge controller can be dispensed with.

BB5 „Busy Bee“ saves on external components

The little bees can handle voltages from 1.71 to 5.5 volts. For the clock, they already have a 50 MHz HFRCO and an 80 kHz LFRCO on-chip. A temperature sensor is also integrated on the MCU.

This space gained around the bees makes the BB5 family agile and increases the range of use for various applications.

In addition, the internal voltage references and the power-on-reset curcit also contribute to saving external components.

The BB50 starts in the smart 2 x 2 mm QFN12 package and ends with its BB52 colleague in the still small 5 x 5 mm QFN32 package. TSSOP-20, -28 and SOIC 16 derivatives are also available.

Functional Security Crossbar
Every pin can handle almost every function. In small applications, it is crucial to avoid complicated wiring. The busy bee counters this typical problem with a highly functional "crossbar". The developer can thus dispense with complex cable routing, which saves time and money.

Key Features



  • 8051 @ 50 MHz
  • 1,8 - 5,5 Volt Service area
  • Up to 32 kB Flash / 2304 B RAM



  • <10 µA Snooze Mode / <30 µs Wakeup
  • 1,3 µA Sleep Mode / <20 ms Wakeup

Housing / Temperature range



  • 2 x 2 mm QFN 12 to 5x5 mm QFN 32
  • TSSOP20 and TSSOP 28
  • SOIC16
  • -40 to +85°C (optional +125°C)

Advanced safety functions


  • 16-Bit CRC


For easy entry into the world of the" Busy Bee".

PRO Kits: BB52-PK5206A / BB51-PK5207A

  • 1x Pro Kit each with BB52 or BB51
  • On Board Debugger
  • On Board Enegy profiler
  • Sensors, push-buttons and expansion Slot
PRO Kits: BB52-PK5206A / BB51-PK5207A

Explorer Kits: BB52-EK27001A / BB51-EK2700A

  • 1x Low cost Explorer Kit each with BB52 or BB51
  • On board debugger
  • Button and one Qwiic and one MikroE expansion slot each for additional hardware
Explorer Kits: BB52-EK27001A / BB51-EK2700A

At SILICON LABS, you get everything from a single source. Hardware in the form of SoC or modules, as well as the matching software stacks and tools.

Simplicity Studio 5 is the central hub for your development. Based on the Eclipse environment, all information and tools are provided here with just a few clicks.

The development environment is rounded off by the unlimited Keil compiler licence, which is of course included.

Start today in the world of the "busy little bees" - We have more information ready for you on request.

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