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STMicroelectronics STM32L021D4P6
- Part No.:
- STM32L021D4P6
- Manufacturer:
- STMicroelectronics
- Category:
- Microcontrollers
- Package:
- 14-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
STM32L021D4P6.pdf
- Description:
- IC MCU 32BIT 16KB FLASH 14TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:413
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Product details
Overview
STM32L021D4P6 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller in TSSOP20 package, featuring 16 KB Flash, 2 KB SRAM, 512 B EEPROM with ECC, 12-bit ADC (1.14 Msps), and hardware AES-128 encryption. It operates from 1.65 V to 3.6 V across –40 °C to +125 °C and delivers 0.54 µA Stop mode + RTC + 2 KB RAM retention - ideal for battery-powered sensor nodes and smart metering endpoints.
For engineers reviewing the STM32L021D4P6 datasheet, STM32L021D4P6 pinout, STM32L021D4P6 application, or STM32L021D4P6 equivalent, key selection criteria include ultra-low standby current (0.23 µA), 5 µs Flash wakeup time, 23 5V-tolerant I/Os, and integrated AES for secure firmware updates in constrained IoT edge devices.
Technical Context
The STM32L021D4P6 implements a single-core Arm Cortex-M0+ running up to 32 MHz with 0.95 DMIPS/MHz performance, supported by multiple clock sources including factory-trimmed 16 MHz HSI (±1%), 32 kHz LSE for RTC calibration, and multispeed MSI (65 kHz–4.2 MHz). Its power architecture integrates programmable voltage detector (PVD), ultra-low-power brownout reset (BOR) with five thresholds, and dynamic voltage scaling for optimized active/low-power mode transitions.
Peripherals are interconnected via a dedicated matrix supporting concurrent DMA transfers across ADC, USART, SPI, I²C, timers, and AES. The device includes two ultra-low-power comparators (operable down to 1.65 V), a temperature sensor, 96-bit unique ID, CRC unit, and serial wire debug (SW-DP) - all designed for deterministic real-time operation in energy-critical embedded systems without external support components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core | Arm Cortex-M0+, 32-bit, up to 32 MHz - enables deterministic real-time control with minimal code footprint |
| Memory | 16 KB Flash with ECC + 2 KB SRAM + 512 B EEPROM with ECC - ensures data integrity and firmware resilience in field-deployed devices |
| Power Modes | 0.23 µA Standby (2 wakeup pins), 0.54 µA Stop + RTC + 2 KB RAM retention - extends coin-cell battery life to >10 years in periodic-sensing applications |
| ADC | 12-bit, 1.14 Msps, 10-channel, operational down to 1.65 V - supports high-resolution analog sensing without external supply rail boosting |
| Crypto | Hardware AES-128 engine - accelerates secure boot, OTA update decryption, and TLS handshake offload without CPU overhead |
| I/O | 23 I/Os, 20 of which are 5V tolerant - simplifies interface to legacy peripherals and industrial logic without level shifters |
| Debug | Serial Wire Debug (SW-DP) - enables non-intrusive real-time tracing and low-pin-count in-circuit debugging |
Pinout & Package
STM32L021D4P6 is housed in a 20-pin TSSOP package (6.5 × 4.4 mm, 0.65 mm pitch), optimized for compact PCB layouts and automated assembly. Pin functions align with STM32L021x4 series standardization, supporting full peripheral mapping within the 20-pin constraint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD, VSS | Power supply and ground | Dual VDD/VSS pairs ensure stable core and I/O domain operation; decoupling required per datasheet layout guidelines |
| NRST | Active-low reset input | Asynchronous reset with internal pull-up; accepts 5V-tolerant logic for compatibility with external supervisors |
| PA0–PA9, PB0–PB7 | General-purpose I/Os | 23 total GPIOs (some multiplexed); 20 support 5V tolerance - enables direct connection to 5V sensors, displays, and UART transceivers |
| PA1, PA2, PA3, PA4, PA5, PA6, PA7, PA9, PA10, PB0, PB1, PB6, PB7 | Alternate function mapping | Support USART, LPUART, SPI, I²C, ADC, comparators, timers - allows full peripheral use without pin expansion |
| BOOT0 | Boot mode selection | Configures boot from system memory (for bootloader execution) or main Flash - critical for field firmware recovery |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low-power BOR | 5 selectable brownout thresholds (1.62 V to 2.52 V) - prevents erratic operation during battery sag while avoiding premature resets |
| RTC with calibration | 32 kHz LSE oscillator with ±10 ppm accuracy and software calibration - sustains precise timekeeping over temperature and aging without external crystal trimming |
| Low-power timer (LPTIM) | 16-bit ultra-low-power timer running from LSE/LSI, independent of CPU clock - enables sub-second wakeups and pulse counting during Stop mode |
| Pre-programmed bootloader | Factory-loaded USART/SPI bootloader - permits firmware updates over serial interface without JTAG debugger or external programmer |
| Hardware ECC | On-the-fly error correction for Flash and EEPROM - eliminates need for external checksum validation and extends memory lifetime in harsh environments |
Applications
| Smart Utility Metering | Wireless Sensor Node |
|---|---|
Use Scenario: Battery-powered gas/water meter reading endpoint transmitting hourly consumption data via NB-IoT or LoRaWAN. IC Role / Device Role / Timing Role: Main controller managing ADC sampling of flow sensors, RTC-based scheduling, AES-encrypted payload generation, and low-power radio interface timing. Use Value: 0.23 µA Standby current and 5 µs wakeup enable >15-year battery life; 512 B EEPROM stores calibration constants and tamper logs with ECC protection. | Use Scenario: Industrial vibration monitor mounted on rotating machinery, logging accelerometer data at 1 kHz and triggering alerts on anomaly detection. IC Role / Device Role / Timing Role: Real-time signal acquisition host with 12-bit ADC oversampling, LPTIM-driven sampling intervals, and hardware CRC for sensor data integrity. Use Value: 1.14 Msps ADC resolution captures transient events; 2 KB SRAM buffers burst samples; Stop mode + RTC preserves context between measurements. |
| Medical Wearable Patch | Asset Tracking Beacon |
Use Scenario: Disposable ECG patch measuring heart rate and rhythm, transmitting encrypted biometric data to smartphone via BLE. IC Role / Device Role / Timing Role: Signal conditioning and secure processing unit interfacing with analog front-end, managing BLE stack timing, and executing AES-128 encryption before transmission. Use Value: 5V-tolerant I/Os simplify connection to op-amp stages; hardware AES reduces CPU load and power-per-bit; 125 °C rating supports sterilization processes. | Use Scenario: GPS-enabled logistics tag reporting location every 6 hours using cellular or satellite uplink in cold-chain transport. IC Role / Device Role / Timing Role: Power manager and secure identity anchor - controls GPS module sleep/wake cycles, validates firmware signatures, and stores cryptographic keys in protected EEPROM. Use Value: 0.54 µA Stop + RTC + 2 KB RAM retention maintains GPS almanac and session state; 96-bit unique ID enables device-level authentication in cloud platforms. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ultra-low-power MCU applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STM32L011D4P6 | Same package and core, but only 16 KB Flash, 1.5 KB SRAM, no EEPROM, no AES | Lacks hardware encryption and data retention memory - unsuitable for secure firmware updates or long-term sensor logging | Select when cost sensitivity outweighs security and nonvolatile data storage requirements |
| STM32L031F6P6 | TSSOP20, 32 KB Flash, 8 KB SRAM, 1 KB EEPROM, AES, but no LPUART or USB | Higher memory and crypto capability, yet missing low-power UART - limits compatibility with certain LPWAN modems | Choose for applications needing larger firmware space and enhanced data logging, where LPUART is not required |
Compared with STM32L011D4P6, the STM32L021D4P6 adds EEPROM and AES for secure, persistent data handling; versus STM32L031F6P6, it trades memory capacity for LPUART integration - making it optimal for compact, secure, communication-centric edge nodes.
Availability
STM32L021D4P6 is available at Aetrix Electronics and suitable for smart metering, wireless sensor networks, medical wearables, and asset tracking applications requiring stable component supply and long-term manufacturability.
Supply support for STM32L021D4P6 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and analog products for industrial, automotive, and consumer markets.
The STM32L0 Access line targets cost-sensitive, ultra-low-power applications demanding robustness, security, and extended battery life - with the STM32L021D4P6 optimized for minimal footprint and maximum peripheral integration in TSSOP20.
FAQ
What is the maximum operating frequency and associated power consumption in Run mode?
The STM32L021D4P6 runs up to 32 MHz with typical current draw of 76 µA/MHz at 3.3 V. At full speed, this equates to ~2.43 mA total active current - verified in datasheet Table 21 under "Run mode, code from Flash." This value assumes all peripherals disabled and includes core, memory, and clock system overhead.
Does STM32L021D4P6 support hardware debugging, and what interface is used?
Yes, it supports Serial Wire Debug (SW-DP) via SWCLK and SWDIO pins (PA14/PA13), enabling full breakpoint, watchpoint, and memory inspection capabilities without requiring additional debug pins. SW-DP consumes negligible power and remains functional in all debug-enabled low-power modes except Standby.
How many I/O pins are 5V tolerant, and which ones are they?
20 of the 23 GPIOs are 5V tolerant, specifically PA0–PA9, PB0–PB7, and PA15. These pins tolerate up to 5.5 V regardless of VDD level, allowing direct interfacing with 5V peripherals such as RS-232 transceivers, industrial sensors, and legacy microcontrollers without external level-shifting circuitry.
Can the internal EEPROM be used for storing calibration data, and what endurance does it offer?
Yes, the 512 B data EEPROM supports byte/word write and erase operations with guaranteed 100,000 write/erase cycles and 20-year data retention at 85 °C (per datasheet Table 43). It includes hardware ECC and sector protection, making it suitable for storing sensor calibration coefficients, device IDs, and security keys in field-deployed equipment.
STM32L021D4P6 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 14-TSSOP (0.173", 4.40mm Width)
- Series:
- STM32L0
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Core Processor:
- ARM® Cortex®-M0+
- Core Size:
- 32-Bit Single-Core
- Speed:
- 32MHz
- Connectivity:
- I2C, IrDA, SPI, UART/USART
- Peripherals:
- Brown-out Detect/Reset, DMA, POR, PWM, WDT
- Number of I/O:
- 11
- Program Memory Size:
- 16KB (16K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- 512 x 8
- RAM Size:
- 2K x 8
- Voltage - Supply (Vcc/Vdd):
- 1.65V ~ 3.6V
- Data Converters:
- A/D 4x12b
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
STM32L021D4P6 FAQ
1.How can I place an order for STM32L021D4P6 through Aetrix?
Please submit a Request for Quotation (RFQ) for STM32L021D4P6 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for STM32L021D4P6 reliable?
The price and inventory of STM32L021D4P6 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM32L021D4P6 is usually 5 days.
3.What payment methods are accepted for STM32L021D4P6?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM32L021D4P6 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM32L021D4P6?
STM32L021D4P6 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM32L021D4P6 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for STM32L021D4P6?
For technical support, including STM32L021D4P6 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM32L021D4P6 requirements.
6.How does Aetrix verify that STM32L021D4P6 is sourced from the original manufacturer or authorized distributors?
All STM32L021D4P6 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that STM32L021D4P6 meets industry standards.
7.What is the process for return or replacement of STM32L021D4P6?
All STM32L021D4P6 units undergo pre-shipment inspection (PSI). If there is an issue with STM32L021D4P6, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The STM32L021D4P6 part is unused and in its original packaging.
Return procedure for STM32L021D4P6:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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