EFM8 Busy Bee Family
EFM8BB2 Data Sheet
The EFM8BB2, part of the Busy Bee family of MCUs, is a multi-
purpose line of 8-bit microcontrollers with a comprehensive feature
set in small packages.
These devices offer high-value by integrating advanced analog and enhanced high-
speed communication peripherals into small packages, making them ideal for space-con-
strained applications. With an efficient 8051 core, enhanced pulse-width modulation, and
precision analog, the EFM8BB2 family is also optimal for embedded applications.
EFM8BB2 applications include the following:
• Motor control
• Consumer electronics
• Sensor controllers
• Medical equipment
• Lighting systems
• High-speed communication hub
KEY FEATURES
• Pipelined 8-bit C8051 core with 50 MHz
maximum operating frequency
• Up to 22 multifunction, 5 V tolerant I/O
pins
• One 12-bit Analog to Digital converter
(ADC)
• Two Low-current analog comparators with
build-in DAC as reference input
• Integrated temperature sensor
• 3-channel PWM / PCA with special
hardware kill/safe state capability
• Five 16-bit timers
• Two UARTs, SPI, SMBus/I2C master/
slave and I2C slave
• Priority crossbar for flexible pin mapping
Core / Memory
CIP-51 8051 Core
(50 MHz)
Flash Program
Memory
(16 KB)
Clock Management
External CMOS
Oscillator
High Frequency
49 MHz RC
Oscillator
High Frequency
24.5 MHz RC
Oscillator
Energy Management
Internal LDO
Regulator
Power-On Reset
RAM Memory
(2304 bytes)
Debug Interface
with C2
Low Frequency
RC Oscillator
Brown-Out
Detector
5 V-to 3.3 V LDO
Regulator
8-bit SFR bus
Serial Interfaces
2 x UART
SPI
High-Speed
I2C Slave
I/O Ports
External
Interrupts
General
Purpose I/O
Timers and Triggers
Timer
0/1/2
Watchdog
Timer
PCA/PWM
Analog Interfaces
ADC
Comparator 0
Security
16-bit CRC
Pin Reset
I
2
C / SMBus
Pin Wakeup
Timer 3/4
Comparator 1
Internal
Voltage
Reference
Lowest power mode with peripheral operational:
Normal
Idle
Suspend
Snooze
Shutdown
silabs.com
| Building a more connected world.
Rev. 1.4
EFM8BB2 Data Sheet
Feature List
1. Feature List
The EFM8BB2 highlighted features are listed below.
• Core:
• Pipelined CIP-51 Core
• Fully compatible with standard 8051 instruction set
• 70% of instructions execute in 1-2 clock cycles
• 50 MHz maximum operating frequency
• Memory:
• Up to 16 KB flash memory, in-system re-programmable
from firmware, including 1 KB of 64-byte sectors and 15
KB of 512-byte sectors.
• Up to 2304 bytes RAM (including 256 bytes standard 8051
RAM and 2048 bytes on-chip XRAM)
• Power:
• 5 V-input LDO regulator
• Internal LDO regulator for CPU core voltage
• Power-on reset circuit and brownout detectors
• I/O: Up to 22 total multifunction I/O pins:
• All pins 5 V tolerant under bias
• Flexible peripheral crossbar for peripheral routing
• 5 mA source, 12.5 mA sink allows direct drive of LEDs
• Clock Sources:
• Internal 49 MHz oscillator with accuracy of ±1.5%
• Internal 24.5 MHz oscillator with ±2% accuracy
• Internal 80 kHz low-frequency oscillator
• External CMOS clock option
• Timers/Counters and PWM:
• 3-channel Programmable Counter Array (PCA) supporting
PWM, capture/compare, and frequency output modes
• 5 x 16-bit general-purpose timers
• Independent watchdog timer, clocked from the low frequen-
cy oscillator
• Communications and Digital Peripherals:
• 2 x UART, up to 3 Mbaud
• SPI™ Master / Slave, up to 12 Mbps
• SMBus™/I2C™ Master / Slave, up to 400 kbps
• I
2
C High-Speed Slave, up to 3.4 Mbps
• 16-bit CRC unit, supporting automatic CRC of flash at 256-
byte boundaries
Analog:
• 12-Bit Analog-to-Digital Converter (ADC)
• 2 x Low-current analog comparators with adjustable refer-
ence
On-Chip, Non-Intrusive Debugging
• Full memory and register inspection
• Four hardware breakpoints, single-stepping
Pre-loaded UART bootloader
Temperature range -40 to 85 ºC or -40 to 125 ºC
• Automotive grade available (requires PPAP)
Single power supply of 2.2 to 3.6 V or 3.0 to 5.25 V
QFN28, QSOP24, and QFN20 packages
•
•
•
•
•
•
With on-chip power-on reset, voltage supply monitor, watchdog timer, and clock oscillator, the EFM8BB2 devices are truly standalone
system-on-a-chip solutions. The flash memory is reprogrammable in-circuit, providing nonvolatile data storage and allowing field up-
grades of the firmware. The on-chip debugging interface (C2) allows non-intrusive (uses no on-chip resources), full speed, in-circuit
debugging using the production MCU installed in the final application. This debug logic supports inspection and modification of memory
and registers, setting breakpoints, single stepping, and run and halt commands. All analog and digital peripherals are fully functional
while debugging. Each device is specified for 2.2 to 3.6 V operation (or up to 5.25 V with the 5 V regulator option). Both the G-grade
and I-grade devices are available in 28-pin QFN, 20-pin QFN, or 24-pin QSOP packages, and A-grade devices are available in 28-pin
QFN or 20-pin QFN packages. All package options are lead-free and RoHS compliant.
silabs.com
| Building a more connected world.
Rev. 1.4 | 2
EFM8BB2 Data Sheet
Ordering Information
2. Ordering Information
EFM8 BB2 2 F 16 G
–
A
–
QFN28 R
Tape and Reel (Optional)
Package Type
Revision
Temperature Grade G (-40 to +85), I (-40 to +125), A (-40 to +125, Automotive Grade)
Flash Memory Size – 16 KB
Memory Type (Flash)
Family Feature Set
Busy Bee 2 Family
Silicon Labs EFM8 Product Line
Figure 2.1. EFM8BB2 Part Numbering
All EFM8B2 family members have the following features:
• CIP-51 Core running up to 50 MHz
• Three Internal Oscillators (49 MHz, 24.5 MHz and 80 kHz)
• SMBus
• I2C Slave
• SPI
• 2 UARTs
• 3-Channel Programmable Counter Array (PWM, Clock Generation, Capture/Compare)
• 5 16-bit Timers
• 2 Analog Comparators
• 12-bit Analog-to-Digital Converter with integrated multiplexer, voltage reference, and temperature sensor
• 16-bit CRC Unit
• AEC-Q100 qualified
• Pre-loaded UART bootloader
In addition to these features, each part number in the EFM8BB2 family has a set of features that vary across the product line. The
product selection guide shows the features available on each family member.
Table 2.1. Product Selection Guide
Pb-free (RoHS Compliant)
Ordering Part Number
Digital Port I/Os (Total)
Comparator 0 Inputs
Comparator 1 Inputs
5-to-3.3 V Regulator
Flash Memory (KB)
Temperature Range
ADC0 Channels
RAM (Bytes)
EFM8BB22F16G-C-QFN28
EFM8BB21F16G-C-QSOP24
EFM8BB21F16G-C-QFN20
EFM8BB22F16I-C-QFN28
16
16
16
16
2304
2304
2304
2304
22
21
16
22
20
20
15
20
10
10
10
10
12
12
7
12
Yes
Yes
Yes
Yes
Yes
—
—
Yes
-40 to +85 ºC
-40 to +85 ºC
-40 to +85 ºC
-40 to +125 ºC
QFN28
QSOP24
QFN20
QFN28
silabs.com
| Building a more connected world.
Rev. 1.4 | 3
Package
EFM8BB2 Data Sheet
Ordering Information
Pb-free (RoHS Compliant)
Ordering Part Number
Digital Port I/Os (Total)
Comparator 0 Inputs
Comparator 1 Inputs
5-to-3.3 V Regulator
Flash Memory (KB)
ADC0 Channels
RAM (Bytes)
Temperature Range
EFM8BB21F16I-C-QSOP24
EFM8BB21F16I-C-QFN20
EFM8BB22F16A-C-QFN28
EFM8BB21F16A-C-QFN20
16
16
16
16
2304
2304
2304
2304
21
16
22
16
20
15
20
15
10
10
10
10
12
7
12
7
Yes
Yes
Yes
Yes
—
—
Yes
—
-40 to +125 ºC
-40 to +125 ºC
-40 to +125 ºC
-40 to +125 ºC
QSOP24
QFN20
QFN28
QFN20
The A-grade (i.e. EFM8BB21F16A-C-QFN20) devices receive full automotive quality production status, including AEC-Q100 qualifica-
tion, registration with International Material Data System (IMDS), and Part Production Approval Process (PPAP) documentation. PPAP
documentation is available at
www.silabs.com
with a registered and NDA approved user account.
silabs.com
| Building a more connected world.
Rev. 1.4 | 4
Package
Table of Contents
1. Feature List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Introduction.
3.2 Power
3.3 I/O.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. 7
. 8
. 8
. 9
. 9
.10
.12
.13
.13
.14
3.4 Clocking .
3.5 Counters/Timers and PWM .
3.7 Analog .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
3.6 Communications and Other Digital Peripherals .
3.8 Reset Sources
3.9 Debugging .
3.10 Bootloader
4. Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.1 Electrical Characteristics . . . . . . .
4.1.1 Recommended Operating Conditions .
4.1.2 Power Consumption. . . . . . .
4.1.3 Reset and Supply Monitor . . . . .
4.1.4 Flash Memory . . . . . . . . .
4.1.5 Power Management Timing . . . .
4.1.6 Internal Oscillators . . . . . . .
4.1.7 External Clock Input . . . . . . .
4.1.8 ADC . . . . . . . . . . . .
4.1.9 Voltage Reference . . . . . . .
4.1.10 Temperature Sensor . . . . . .
4.1.11 1.8 V Internal LDO Voltage Regulator
4.1.12 5 V Voltage Regulator. . . . . .
4.1.13 Comparators . . . . . . . . .
4.1.14 Port I/O . . . . . . . . . .
4.2 Thermal Conditions .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
4.3 Absolute Maximum Ratings .
4.4 Typical Performance Curves .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.16
.16
.17
.20
.20
.21
.21
.22
.23
.24
.25
.25
.25
.26
.27
.27
.28
.29
5. Typical Connection Diagrams
5.1 Power
5.2 Debug
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. . . . . . . . . . . . . . . . . . . . . . . . 33
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.33
.34
.34
5.3 Other Connections .
6. Pin Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6.1 EFM8BB2x-QFN28 Pin Definitions .
silabs.com
| Building a more connected world.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.35
Rev. 1.4 | 5