EFM8 Sleepy Bee Family
EFM8SB2 Reference Manual
The EFM8SB2, part of the Sleepy Bee family of MCUs, is the
world’s most energy friendly 8-bit microcontrollers with a compre-
hensive feature set in small packages.
These devices offer lowest power consumption by combining innovative low energy tech-
niques and short wakeup times from energy saving modes into small packages, making
them well-suited for any battery operated applications. With an efficient 8051 core, 6-bit
current reference, and precision analog, the EFM8SB2 family is also optimal for embed-
ded applications.
EFM8SB2 applications include the following:
ENERGY FRIENDLY FEATURES
• Lowest MCU sleep current with supply
brownout detection (50 nA)
• Lowest MCU active current with these
features (170 μA / MHz at 24.5 MHz clock
rate)
• Lowest MCU sleep current using internal
RTC operating and supply brownout
detection (<300 nA)
• Ultra-fast wake up for digital and analog
peripherals (< 2 μs)
• Integrated low drop out (LDO) voltage
regulator to maintain ultra-low active
current at all voltages
• Hand-held devices
• Industrial controls
• Battery-operated consumer electronics
• Sensor interfaces
Security
I/O Ports
Core / Memory
Clock Management
CIP-51 8051 Core
(25 MHz)
Energy Management
Internal LDO
Regulator
Brown-Out Detector
Power-On Reset
8-bit SFR bus
Serial Interfaces
Timers and Triggers
Analog Interfaces
2 x SPI
Pin Reset
Timers
0/1/2/3
PCA/PWM
Watchdog
Timer
Comparator 0
16/32-bit CRC
Flash Program
Memory
(up to 64 KB)
RAM Memory
(4352 bytes)
Debug Interface
with C2
Lowest power mode with peripheral operational:
Idle
Normal
Suspend
Sleep
High Frequency
24.5 MHz RC
Oscillator
Pin Wakeup
External
Interrupts
General
Purpose I/O
I
2
C / SMBus
UART
External 32 kHz
RTC Oscillator
Low Power 20
MHz RC
Oscillator
External
Oscillator
Real Time
Clock
Internal Voltage
Reference
Comparator 1
ADC
Internal Current Reference
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Rev. 0.1