STM32L021D4P7 - Ultra-Low-Power ARM Cortex-M0+ MCU | STMicroelectronics
MPN: STM32L021D4P7 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.15 | $2.15 |
| 10 | $1.93 | $19.30 |
| 100 | $1.72 | $172.00 |
| 500 | $1.55 | $775.00 |
| 1,000 | $1.38 | $1,380.00 |
Drop-in alternatives for STM32L021D4P7 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
STM32L011D4P7
β Drop-Inπ Reference alternative (not in catalog)
STM32L031D4P7
β Drop-Inπ Reference alternative (not in catalog)
STM32L041D4P7
β Drop-Inπ Reference alternative (not in catalog)
EFM8BB10F8G-A-QFN20
β Drop-Inπ Reference alternative (not in catalog)
PIC16F18313-I/SN
β Drop-Inπ Reference alternative (not in catalog)
STM32L021D4P7 Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M0+ |
| Max Clock Frequency | 32 MHz |
| Flash Memory | 16 KB |
| SRAM | 8 KB |
| EEPROM | 512 bytes |
| Supply Voltage Range | 1.65 V to 3.6 V |
| Operating Temperature Range | -40C to +125C |
| Package | TSSOP-14 |
| Mounting Type | Surface Mount |
| Number of I/O Pins | 11 |
| ADC Resolution | 12-bit |
| ADC Channels | 8 |
| Communication Interfaces | I2C, SPI, USART |
| Low-Power Modes | Sleep, Low-power Run, Low-power Sleep, Stop, Standby |
| Standby Current (with RTC) | 0.29 Β΅A |
| Stop Mode Current | 3.4 Β΅A |
| RoHS Status | Compliant |
STM32L021D4P7 Pin Configuration
| Pin 1 | VBAT β Backup battery supply for RTC and backup registers |
| Pin 2 | PC14 β GPIO / OSC32_IN |
| Pin 3 | PC15 β GPIO / OSC32_OUT |
| Pin 4 | NRST β Reset (active low) |
| Pin 5 | VDDA β Analog power supply |
| Pin 6 | PA0 β GPIO / ADC_IN0 / USART2_CTS |
| Pin 7 | PA1 β GPIO / ADC_IN1 / USART2_RTS |
| Pin 8 | PA2 β GPIO / ADC_IN2 / USART2_TX |
| Pin 9 | PA3 β GPIO / ADC_IN3 / USART2_RX |
| Pin 10 | PA4 β GPIO / ADC_IN4 / SPI1_NSS |
| Pin 11 | PA5 β GPIO / ADC_IN5 / SPI1_SCK |
| Pin 12 | PA6 β GPIO / ADC_IN6 / SPI1_MISO |
| Pin 13 | PA7 β GPIO / ADC_IN7 / SPI1_MOSI |
| Pin 14 | VSS β Ground |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this digital IC. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
STM32L021D4P7 is suitable for 6 applications: Wearable Devices, Smart Sensors, Medical Monitoring Devices, Industrial IoT Nodes, Portable Consumer Electronics, Energy Harvesting Systems.
Wearable Devices
The STM32L021D4P7 is ideal for wearable devices such as fitness trackers and smart watches. Its ultra-low power consumption (0.29 Β΅A standby) allows operation on a coin cell battery for years. The small TSSOP-14 package fits space-constrained designs. The MCU can handle sensor data acquisition, processing, and wireless communication while maintaining long battery life. Its multiple low-power modes enable the device to sleep between measurements, waking only when needed. The integrated 12-bit ADC and communication interfaces (I2C, SPI, USART) support various sensors and connectivity options. The wide supply voltage range (1.65V to 3.6V) ensures compatibility with single-cell batteries. The STM32L0 series is well-supported by ST's development tools, accelerating time-to-market.
Recommended
Smart Sensors
The STM32L021D4P7 is perfect for smart sensors in industrial and consumer applications. Its ultra-low power consumption allows battery-powered sensors to operate for extended periods. The MCU can read analog sensors via its 12-bit ADC, process data, and transmit results over I2C, SPI, or USART. The multiple low-power modes enable the sensor to sleep between readings, conserving energy. The wide operating temperature range (-40C to +125C) makes it suitable for harsh environments. The small package and low pin count simplify PCB design. The STM32L0 series offers a rich set of peripherals, including comparators and timers, which can be used for sensor signal conditioning. The device's robust design and long-term availability make it a reliable choice for industrial IoT.
Recommended
Medical Monitoring Devices
The STM32L021D4P7 is well-suited for medical monitoring devices such as glucose meters, pulse oximeters, and portable ECG monitors. Its ultra-low power consumption ensures long battery life, critical for patient convenience. The MCU can process biosignals from sensors, perform calculations, and display results on a small screen or transmit data wirelessly. The 12-bit ADC provides sufficient resolution for accurate signal acquisition. The device's small footprint allows for compact, portable designs. The STM32L0 series includes features like a unique ID for device authentication and secure communication. The wide supply voltage range supports various battery chemistries. The MCU's reliability and long-term availability are essential for medical devices that must meet regulatory standards.
Recommended
Industrial IoT Nodes
The STM32L021D4P7 is an excellent choice for industrial IoT nodes that monitor equipment health, environmental conditions, or energy usage. Its ultra-low power consumption enables deployment in remote locations where battery replacement is difficult. The MCU can interface with various sensors, process data locally, and transmit it to a central system via wired or wireless interfaces. The wide operating temperature range (-40C to +125C) ensures reliable operation in industrial environments. The device's multiple low-power modes allow it to conserve energy during idle periods. The STM32L0 series is designed for robustness, with features like brown-out reset and watchdog timers. The small package and low cost make it suitable for large-scale deployments.
Recommended
Portable Consumer Electronics
The STM32L021D4P7 is ideal for portable consumer electronics like remote controls, smart tags, and digital thermometers. Its ultra-low power consumption extends battery life, reducing the frequency of battery replacement. The MCU can handle user input, display output, and communication with other devices. The small TSSOP-14 package is perfect for compact designs. The device's low cost makes it suitable for high-volume consumer products. The STM32L0 series offers a range of low-power modes that can be tailored to the application's needs. The integrated EEPROM allows for storing user settings or calibration data without external memory. The wide supply voltage range supports various battery types, including coin cells and AA batteries.
Recommended
Energy Harvesting Systems
The STM32L021D4P7 is well-suited for energy harvesting systems that draw power from solar cells, thermoelectric generators, or vibration harvesters. Its ultra-low power consumption allows it to operate with the limited energy available from these sources. The MCU can manage power conversion, store energy in capacitors or batteries, and perform periodic tasks. The wide supply voltage range (1.65V to 3.6V) is compatible with typical energy harvesting outputs. The device's low-power modes enable it to sleep while energy is being harvested, waking only when sufficient energy is available. The STM32L0 series includes features like a real-time clock that can wake the MCU at scheduled intervals. The small package and low cost make it ideal for distributed sensor networks powered by energy harvesting.
Recommended
Recommended Products Summary
Engineering reference data for STM32L021D4P7 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STM32L011D4P7 | STM32L031D4P7 | STM32L041D4P7 | EFM8BB10F8G-A-QFN20 | PIC16F18313-I/SN |
|---|---|---|---|---|---|---|
| Package | TSSOP-14 | TSSOP-14 | TSSOP-14 | TSSOP-14 | TSSOP-14 | TSSOP-14 |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | Silicon Labs | Microchip Technology |
| Core | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | ARM Cortex-M0+ | 8051 | PIC16 |
| Max Clock Frequency | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 25 MHz | 32 MHz |
| Flash Memory | 16 KB | 8 KB | 32 KB | 32 KB | 8 KB | 3.5 KB |
| SRAM | 8 KB | 2 KB | 8 KB | 8 KB | 1 KB | 256 B |
| Supply Voltage Range | 1.65V to 3.6V | 1.65V to 3.6V | 1.65V to 3.6V | 1.65V to 3.6V | 1.8V to 3.6V | 1.8V to 5.5V |
| Standby Current | 0.29 Β΅A | 0.29 Β΅A | 0.29 Β΅A | 0.29 Β΅A | 0.05 Β΅A | 0.02 Β΅A |
Key Differentiators
- Ultra-low standby current of 0.29 Β΅A with RTC (vs PIC16F18313-I/SN)
- ARM Cortex-M0+ core with 32 MHz performance (vs EFM8BB10F8G-A-QFN20)
- Integrated EEPROM (512 bytes) (vs STM32L011D4P7)
Design Notes
Decouple the VDD and VDDA pins with 100 nF ceramic capacitors placed as close to the pins as possible. Additionally, use a 1 Β΅F capacitor on VDDA for analog noise filtering. For battery-powered designs, consider using the VBAT pin for backup power to maintain RTC functionality when the main supply is removed.
For the TSSOP-14 package, ensure adequate copper pour on the ground plane to minimize noise. Keep high-speed signals short and away from analog pins. The exposed pad (if present) should be soldered to the ground plane for thermal and electrical performance. Follow ST's layout guidelines in the datasheet for optimal EMC performance.
When using low-power modes, ensure that all unused I/Os are configured properly to avoid floating inputs, which can increase leakage current. Also, verify that the RTC clock source is correctly configured to achieve the specified standby current. Failure to do so may result in higher power consumption than expected.
Compliance Information
RoHS and REACH compliant per STMicroelectronics product page. Not AEC-Q100 qualified; this is a general-purpose MCU.
