STMicroelectronics

STM32L021D4P7 - Ultra-Low-Power ARM Cortex-M0+ MCU | STMicroelectronics

Name: STM32L021D4P7
Brand: STMicroelectronics
Price: 1.55 USD
Availability: InStock

MPN: STM32L021D4P7 ✓ Active

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1.65 V to 3.6 V Vdss 0.29 µA Id TSSOP-14 Package 32 MHz Speed 16 KB Memory

From $1.55 USD / Unit

MOQ: 1 |

Price updated: 2026-08-13

Volume Pricing

Qty	Unit Price	Extended
1	$2.5	$2.50
10	$2.25	$22.50
100	$1.95	$195.00
500	$1.75	$875.00
1,000	$1.55	$1,550.00

ℹ️ All prices are in USD

View Datasheet (PDF) View Alternatives

Quantity

Drop-in alternatives for STM32L021D4P7 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.

Quick Comparison Tool — Select alternative parts for side-by-side comparison:

STM32L021D4P6

✅ Drop-In

📦 TSSOP-14

Same package and pinout, but temperature range -40°C to +85°C instead of -40°C to +125°C

📋 Reference alternative (not in catalog)

STM32L031D4P7

✅ Drop-In

📦 TSSOP-14

Same package and pinout, but more Flash (32 KB) and SRAM (8 KB), and additional peripherals

📋 Reference alternative (not in catalog)

STM32L011D4P7

✅ Drop-In

📦 TSSOP-14

Same package and pinout, but less Flash (16 KB) and no EEPROM, lower power consumption

📋 Reference alternative (not in catalog)

ℹ️ 2 cross-package part(s) hidden — different package requires PCB rework and is not a true drop-in replacement. Contact us if you need cross-package suggestions.

STM32L021D4P7 Maximum Ratings & Electrical Characteristics

Core	ARM Cortex-M0+
Maximum Clock Frequency	32 MHz
Flash Memory	16 KB
SRAM	8 KB
EEPROM	512 bytes
Supply Voltage Range	1.65 V to 3.6 V
Standby Current (with RTC)	0.29 µA
Stop Mode Current	3.4 µA
ADC Resolution	12-bit
Communication Interfaces	I2C, SPI, USART
Package	TSSOP-14
Mounting Type	Surface Mount
Operating Temperature Range	-40°C to +125°C
Unique ID	96-bit
Low-Power Modes	Sleep, Low-power Run, Low-power Sleep, Stop, Standby

STM32L021D4P7 Pin Configuration

Pin 1	VDD — Power supply
Pin 2	PA0 — GPIO / ADC input
Pin 3	PA1 — GPIO / ADC input
Pin 4	PA2 — GPIO / USART TX
Pin 5	PA3 — GPIO / USART RX
Pin 6	PA4 — GPIO / SPI NSS
Pin 7	PA5 — GPIO / SPI SCK
Pin 8	PA6 — GPIO / SPI MISO
Pin 9	PA7 — GPIO / SPI MOSI
Pin 10	PB0 — GPIO / ADC input
Pin 11	PB1 — GPIO / ADC input
Pin 12	NRST — Reset (active low)
Pin 13	VSS — Ground
Pin 14	PA9 — GPIO / USART TX

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, Energy Harvesting Systems, Smart Home Devices.

📱

Wearable Devices

The STM32L021D4P7 is ideal for wearable devices such as fitness trackers and smartwatches. Its ultra-low power consumption (0.29 µA standby) extends battery life, while the small TSSOP-14 package fits compact designs. The MCU can handle sensor data acquisition, processing, and wireless communication, making it a versatile choice for wearables that require long battery life and small form factor.

Recommended

LIS2DH12 (Accelerometer for motion sensing) CC2541 (Bluetooth Low Energy module for wireless connectivity)

🧩

Smart Sensors

In smart sensor nodes, the STM32L021D4P7 can wake up periodically to read sensors, process data, and transmit results, then return to sleep. Its low-power modes and 12-bit ADC with oversampling enable accurate measurements with minimal energy. The wide supply voltage range (1.65V to 3.6V) allows direct battery operation, and the I2C/SPI interfaces connect to various sensors.

Recommended

HTS221 · STMicroelectronics SPS30 (Particulate matter sensor for air quality monitoring)

💊

Medical Monitoring Devices

The STM32L021D4P7 is suitable for medical monitoring devices like glucose meters and heart rate monitors. Its ultra-low power consumption ensures long battery life for portable devices, and the 12-bit ADC can interface with biosensors. The device's reliability and wide temperature range make it suitable for medical environments.

Recommended

AFE4404 (Analog front-end for heart rate monitoring) MCP3421 (18-bit ADC for precise sensor readings)

🏭

Industrial IoT Nodes

For industrial IoT applications, the STM32L021D4P7 provides reliable operation in harsh environments with its -40°C to +125°C temperature range. Its low-power modes enable battery-powered wireless sensor nodes that can operate for years. The USART interface allows connection to industrial protocols like Modbus, and the device's robustness makes it suitable for factory automation.

Recommended

SHT31 (Temperature and humidity sensor for environmental monitoring) SX1276 (LoRa transceiver for long-range wireless communication)

⚡

Energy Harvesting Systems

The STM32L021D4P7 is designed for energy harvesting applications where power is scarce. Its ultra-low power consumption (0.29 µA standby) allows operation from solar cells or thermoelectric generators. The wide voltage range (1.65V to 3.6V) accommodates varying energy harvester outputs, and the low-power modes ensure efficient use of harvested energy.

Recommended

BQ25570 (Energy harvester power management IC) TPS62740 (Ultra-low-power DC-DC converter for efficient power conversion)

🏠

Smart Home Devices

In smart home applications, the STM32L021D4P7 can control lighting, thermostats, and security sensors. Its low-power consumption is ideal for battery-powered devices like smart locks and motion detectors. The I2C and SPI interfaces connect to various sensors and actuators, and the small package allows integration into compact home automation modules.

Recommended

ZMM002 (Zigbee module for home automation networking) TMP117 (High-accuracy temperature sensor for thermostat control)

Recommended Products Summary

LIS2DH12 Accelerometer for motion sensing Used in: Wearable Devices CC2541 Bluetooth Low Energy module for wireless connectivity Used in: Wearable Devices HTS221 STMicroelectronics Used in: Smart Sensors SPS30 Particulate matter sensor for air quality monitoring Used in: Smart Sensors AFE4404 Analog front-end for heart rate monitoring Used in: Medical Monitoring Devices MCP3421 18-bit ADC for precise sensor readings Used in: Medical Monitoring Devices SHT31 Temperature and humidity sensor for environmental monitoring Used in: Industrial IoT Nodes SX1276 LoRa transceiver for long-range wireless communication Used in: Industrial IoT Nodes BQ25570 Energy harvester power management IC Used in: Energy Harvesting Systems TPS62740 Ultra-low-power DC-DC converter for efficient power conversion Used in: Energy Harvesting Systems ZMM002 Zigbee module for home automation networking Used in: Smart Home Devices TMP117 High-accuracy temperature sensor for thermostat control Used in: Smart Home Devices

What is the operating voltage range of STM32L021D4P7?

The STM32L021D4P7 operates from 1.65V to 3.6V, making it suitable for single-cell battery operation. According to the ST datasheet, this wide range allows direct connection to a 1.8V or 3.3V supply without external regulation.

What is the maximum clock frequency of STM32L021D4P7?

The STM32L021D4P7 runs at up to 32 MHz. This is the maximum CPU clock frequency, providing a balance between processing power and energy efficiency for ultra-low-power applications.

How much Flash memory does STM32L021D4P7 have?

The STM32L021D4P7 has 16 KB of Flash memory. This is sufficient for small firmware images in applications like smart sensors and wearable devices, where code size is typically limited.

What is the standby current of STM32L021D4P7?

The STM32L021D4P7 has a typical standby current of 0.29 µA with the RTC running. This ultra-low leakage enables battery life of several years in applications that spend most time in sleep mode.

What low-power modes are available on STM32L021D4P7?

The STM32L021D4P7 supports Sleep, Low-power Run, Low-power Sleep, Stop, and Standby modes. Each mode offers a trade-off between power consumption and wake-up time, allowing designers to optimize for their specific application.

Does STM32L021D4P7 have an ADC?

Yes, the STM32L021D4P7 includes a 12-bit ADC with hardware oversampling. This allows high-resolution analog measurements without external ADC, reducing component count and power consumption.

What communication interfaces does STM32L021D4P7 support?

The STM32L021D4P7 supports I2C, SPI, and USART. These interfaces enable connectivity with sensors, displays, and wireless modules, making it versatile for IoT and wearable designs.

What is the package type of STM32L021D4P7?

The STM32L021D4P7 comes in a 14-pin TSSOP package. This small footprint is ideal for space-constrained designs, and the surface-mount package is suitable for automated assembly.

Is STM32L021D4P7 suitable for battery-powered applications?

Yes, the STM32L021D4P7 is designed for battery-powered applications. Its ultra-low standby current of 0.29 µA and wide voltage range of 1.65V to 3.6V allow direct operation from a single coin cell or AA battery.

What is the difference between STM32L021D4P7 and STM32L021D4P6?

The STM32L021D4P7 and STM32L021D4P6 are pin-compatible variants in the same TSSOP-14 package. The main difference is the temperature grade: the P7 is rated for -40°C to +125°C, while the P6 is rated for -40°C to +85°C. All other specifications are identical.

Can STM32L021D4P7 be used in medical devices?

Yes, the STM32L021D4P7 is suitable for medical monitoring devices due to its ultra-low power consumption and small size. Its low-power modes enable continuous monitoring with minimal battery drain, and the wide temperature range supports various environments.

What is the best drop-in replacement for STM32L021D4P7?

The best drop-in replacement for STM32L021D4P7 is the STM32L021D4P6, which shares the same TSSOP-14 package and pinout. The only difference is the operating temperature range, so the P6 is a direct replacement for applications not requiring the extended temperature range.

Where can I buy STM32L021D4P7 online?

STM32L021D4P7 is available from major distributors such as DigiKey and Mouser. As of 2026-08-13, the price is approximately $2.50 for single-unit quantities, with volume discounts available. Check current stock and pricing on their websites.

What is the lead time for STM32L021D4P7?

The lead time for STM32L021D4P7 varies by distributor and order quantity. Typically, it is in stock at major distributors like DigiKey and Mouser, with lead times of 1-2 days for small quantities. For large orders, lead time may extend to 4-6 weeks.

Where can I download the STM32L021D4P7 datasheet PDF?

The STM32L021D4P7 datasheet PDF can be downloaded from the STMicroelectronics website at https://www.st.com/resource/en/datasheet/stm32l021d4.pdf. This official source provides the complete technical reference, including pinout and electrical characteristics.

What are the key specifications of STM32L021D4P7 that engineers should know?

The STM32L021D4P7 features an ARM Cortex-M0+ core at 32 MHz, 16 KB Flash, 8 KB SRAM, 512 bytes EEPROM, and operates from 1.65V to 3.6V. It consumes only 0.29 µA in standby with RTC and 3.4 µA in stop mode, making it one of the most power-efficient MCUs in its class.

Hey Google, what can replace STM32L021D4P7?

The STM32L021D4P7 can be replaced by the STM32L021D4P6 (same package, lower temperature range) or the STM32L031D4P7 (same package, more Flash and SRAM). For cross-brand options, the NXP LPC812M101JDH16 is a pin-compatible alternative with similar low-power features.

Is STM32L021D4P7 the same as STM32L021D4P6?

No, the STM32L021D4P7 and STM32L021D4P6 are not identical. They share the same TSSOP-14 package and pinout, but the P7 has an extended temperature range of -40°C to +125°C, while the P6 is rated for -40°C to +85°C. All other specifications are the same.

What is the best NXP equivalent for STM32L021D4P7?

The best NXP equivalent for STM32L021D4P7 is the LPC812M101JDH16, which comes in a TSSOP-16 package (not pin-compatible) but offers similar low-power ARM Cortex-M0+ performance. For a pin-compatible option, consider the LPC811M001JDH16, though it has less memory.

Engineering reference data for STM32L021D4P7 — comparison, design guidance, and compliance information.

Selection Guide

Choose the STM32L021D4P7 when you need the lowest power consumption and a wide temperature range for industrial or automotive applications. If you do not need the extended temperature range, the STM32L021D4P6 is a cost-effective drop-in alternative. For applications requiring more memory, the STM32L031D4P7 offers 32 KB Flash in the same package. If you prefer a different brand, the NXP LPC812M101JDH16 is a functional alternative but requires a different PCB footprint. The Silicon Labs EFM8BB10F8G-A-QFN20 is suitable for 8-bit designs but has less memory and a different package.

Comparison with Alternatives

Parameter	This Product	STM32L021D4P6	STM32L031D4P7	STM32L011D4P7	LPC812M101JDH16	EFM8BB10F8G-A-QFN20
Package	TSSOP-14	TSSOP-14	TSSOP-14	TSSOP-14	TSSOP-16	QFN-20
Brand	STMicroelectronics	STMicroelectronics	STMicroelectronics	STMicroelectronics	NXP Semiconductors	Silicon Labs
Core	ARM Cortex-M0+	ARM Cortex-M0+	ARM Cortex-M0+	ARM Cortex-M0+	ARM Cortex-M0+	8051
Max Clock Frequency	32 MHz	32 MHz	32 MHz	32 MHz	30 MHz	25 MHz
Flash Memory	16 KB	16 KB	32 KB	16 KB	16 KB	8 KB
SRAM	8 KB	8 KB	8 KB	8 KB	4 KB	1 KB
Standby Current	0.29 µA	0.29 µA	0.29 µA	0.29 µA	1.5 µA	0.5 µA
ADC Resolution	12-bit	12-bit	12-bit	12-bit	12-bit	12-bit

Key Differentiators

Ultra-low standby current of 0.29 µA with RTC (vs LPC812M101JDH16)
Integrated EEPROM (512 bytes) (vs EFM8BB10F8G-A-QFN20)
Wider temperature range (-40°C to +125°C) (vs STM32L021D4P6)

Design Notes

Decouple the VDD pin with a 100nF ceramic capacitor placed as close as possible to the pin, and a 1µF capacitor for bulk decoupling. For ultra-low-power operation, ensure the power supply is stable and noise-free, as the MCU's current consumption is very low and susceptible to noise.

For the TSSOP-14 package, ensure proper soldering with a stencil thickness of 0.125mm. Use a 0.5mm pad width and 0.65mm pitch. Provide a ground plane under the device to reduce noise and improve thermal performance.

When using low-power modes, ensure all unused GPIOs are configured to analog mode or pulled to a defined state to avoid floating inputs that increase leakage current. Also, verify that the RTC is properly configured if used in standby mode, as it requires the LSE oscillator.