M251KE3AE

The NuMicro® M251KE3AE is a low-power microcontroller based on Arm® Cortex®-M23 core for Armv8-M architecture. It runs up to 48 MHz with 128 Kbytes embedded Flash memory and 16 Kbytes embedded SRAM , 4 Kbytes Flash loader memory ( LDROM ) for In-System Programming ( ISP ) , The 32-bit low-power microcontrollers supports wide supply voltage from 1.8 ~ 5.5 V and operating temperature range from - 40 ℃ ~ + 105 ℃ .

The NuMicro® M251KE3AE behaves low power consumption in Normal Run mode 138 μA / MHz at 48 MHz , Idle mode 60 μA / MHz , power down mode 2.5 μA ( RTC on, RAM retention ) , power down mode 1.7 μA ( RTC off, RAM retention ) and Deep Power-down mode. The NuMicro® M251KE3AE series integrates RTC with independent VBAT voltage source pin to support low power mode with main power off and VBAT only. It’s low power, wide supply voltage and fast wake-up features make it suitable for battery-powered IoT applications.

The NuMicro® M251KE3AE provides 8 channels of Nuvoton proprietary interface “Programmable Serial I / O” ( PSIO ) capable of generating specific waveform to emulate arbitrary serial communication protocols to connect with specific peripherals by PSIO hardware engine. PSIO can be treated as extension of popular serial communication standard ( UART , SPI …etc. ) , niche serial communication standard (specific protocol for EEPROM, cardreader…etc.) and proprietary protocol ( SPI -like protocol for LED-lighting application…etc. ). This PSIO hardware engine can simulate comprehensive serial communication protocol with low CPU loading, low control complexity and high timing precision at the same time.High elasticity and flexibility makes PSIO being a powerful and useful tool while connecting to diverse peripherals.

The NuMicro® M251KE3AE integrates Voltage Adjustable Interface ( VAI ) , with 6 I/O pins to support the 2nd I/O voltage from 1.65 ~ 5.5 V to save level shifter components while connecting to external devices.

The NuMicro® M251KE3AE series provides 1-region programable eXecute-Only-Memory ( XOM ) to secure critical program codes. A tamper pin is implemented to avoid malicious damage from hacker. Accompany with 96-bit Unique Identification ( UID ) and 128-bit Unique Customer Identification ( UCID ) to enhance the product security.

The NuMicro® M251KE3AE is equipped with plenty of peripherals such as Timers, Watchdog Timers, RTC, External Bus Interface (EBI), GPIOs x85, up to 24 channels of PWM, Universal Serial Control Interface (USCI) x3, UART x3, QSPI x1, SPI/ I²S x1, I²C x2, ISO-7816-3 x1, PDMA x8, makes it highly suitable for connecting comprehensive external modules and LED lighting control. The M251KE3AE integrates high performance analog front-end circuit blocks, such as 16 channels of 12-bit 880 kSPS ADC, analog comparator ( ACMP ), temperature sensor, low voltage reset ( LVR ) and brown-out detector ( BOD ) to enhance product performance, reduce external components and form factor simultaneously.

The package types of the M251KE3AE is LQFP128 ( 14 mm x 14 mm ). Pin-to-pin compatible in same package makes optimizing product features and performance easily.

Target Application:

Smart Home / Smart Home Appliance
Industrial Control / Industrial Automation
Smart City
IoT Device
Security Alarm System
Electronic Payments
Communication Modules
Portable Wireless Data Collector
Smart Door lock
Handheld Medical Device
( GPS ) Location Tracker
Electronic Shelf Labels ( ESL )

Key Features:

• Operating Characteristics
- Voltage range: 1.8 V ~ 5.5 V
- Temperature range: - 40 ℃ ~ 105 ℃

• Core
- Arm® Cortex®-M23, Armv8-M, 48 MHz
- 32-bit H / W multiplier / divider

• Memories
- 128 KB Flash
- 16 KB SRAM
- 4 KB LDROM
- 1-region eXecute-Only-Memory ( XOM )
- ISP / ICP / IAP programming

• Clocks
- 4 ~ 32 MHz external high speed crystal oscillator ( HXT ) for precise timing operation
- 32.768 kHz external low speed crystal oscillator ( LXT ) for RTC function and low-power system operation
- 48 MHz internal high speed RC oscillator ( HIRC ) for system operation
- 4.032 MHz internal high speed RC oscillator ( MIRC ) for system operation
- 38.4 kHz internal low speed RC oscillator ( LIRC ) for Watchdog Timer and wake-up operation.

• Power management
- Integrated with Power-on Reset, Brown-out Reset and Low Voltage Reset
- Built-in LDO
- Support RTC with independent VBAT voltage source pin

• Low Power Consumption
- 138 μA / MHz in operating mode
- 60 μA / MHz in idle mode
- 2.5 μA in Power down mode ( RTC on, RAM retention )
- 1.7 μA in Power down mode ( RTC off, RAM retention )
- 1.45 μA in Deep Power down mode

• RTC
- Supports external power pin VBAT ( Standalone VBAT for RTC power domain )

• Timers
- Up to 4 * 32-bit timers

• PDMA
- 8 channels

• PWM
- 24-channels PWM
- Supports trigger ADC
- Supports maximum clock frequency up to 96 MHz
- Supports independent mode for PWM output / Capture input channel
- Supports complementary mode for 3 complementary paired PWM output channel

• Analog
- 16 channels 12-bit 880 kSPS ADC
- 2 sets of rail-to-rail comparators ( ACMP )

• Communication interfaces
- 3 sets of USCI Configured as UART, SPI or I²C)
- 3 sets of UART interface
- 1 set of QSPI interface
- 1 set of SPI / I²S interface ( Configured as SPI or I²S )
- 2 sets of I²C interfaces
- 1 set of Smart Card Interface (ISO-7816-3)
- 16 / 8-bits EBI ( External Bus Interface ) interface

• VAI ( Voltage Adjustable Interface )
- 6 I/O pins to support the 2nd I/O voltage from 1.65 ~ 5.5 V, applied voltage to the VDDIO pin

• PSIO ( Programmable Serial I / O )
- PSIO ( Programmable Serial I / O ) is capable of generating specific waveform to emulate arbitrary serial communication protocols to connect with specific peripherals by PSIO hardware engine.
- 8 PSIO pins

• 96-bit Unique ID ( UID )

• 128-bit Unique Customer ID ( UCID )

• Packages
- LQFP128 ( 14 mm x 14 mm )