STMicroelectronics

STM32L552RET6 - 110MHz Arm Cortex-M33 MCU with TrustZone | STMicroelectronics

MPN: STM32L552RET6 βœ“ Active
In Stock (99,999) Ships in 1-3 business days
1.71 V to 3.6 V Vdss 100 nA (with backup domain) Id LQFP-64 (10x10 mm) Package 110 MHz Speed 512 KB Memory
$8.5 USD / Unit
MOQ: 1 |
Volume Pricing
Qty Unit Price Extended
1 $8.5 $8.50
10 $7.65 $76.50
100 $6.8 $680.00
500 $6.12 $3,060.00
1,000 $5.44 $5,440.00
ℹ️ All prices are in USD

Drop-in alternatives for STM32L552RET6 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:

STM32L552RCT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package and pinout, but 256 KB flash and 128 KB SRAM (half the memory)

πŸ“‹ Reference alternative (not in catalog)

STM32L552RET6Q

βœ… Drop-In
πŸ“¦ LQFP-64
Same die and package, AEC-Q100 automotive grade

πŸ“‹ Reference alternative (not in catalog)

STM32L552RCT6Q

βœ… Drop-In
πŸ“¦ LQFP-64
Automotive grade with reduced memory (256 KB flash, 128 KB SRAM)

πŸ“‹ Reference alternative (not in catalog)

STM32L552R8T6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 64 KB flash and 32 KB SRAM (significantly less memory)

πŸ“‹ Reference alternative (not in catalog)

STM32L552RBT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 128 KB flash and 64 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RGT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 1 MB flash and 256 KB SRAM (more flash)

πŸ“‹ Reference alternative (not in catalog)

STM32L552RDT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 384 KB flash and 256 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RCT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 256 KB flash and 128 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552R8T6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 64 KB flash and 32 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RBT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 128 KB flash and 64 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RGT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 1 MB flash and 256 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RDT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 384 KB flash and 256 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RCT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 256 KB flash and 128 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552R8T6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 64 KB flash and 32 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RBT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 128 KB flash and 64 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RGT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 1 MB flash and 256 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RDT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 384 KB flash and 256 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RCT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 256 KB flash and 128 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552R8T6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 64 KB flash and 32 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RBT6

βœ… Drop-In
πŸ“¦ LQFP-64
Same package, but 128 KB flash and 64 KB SRAM

πŸ“‹ Reference alternative (not in catalog)

STM32L552RET6 Maximum Ratings & Electrical Characteristics

Core Arm Cortex-M33 with TrustZone
Max Clock Frequency 110 MHz
Flash Memory 512 KB
SRAM 256 KB
Supply Voltage 1.71 V to 3.6 V
Operating Temperature -40C to +85C
Package LQFP-64 (10x10 mm)
GPIO Pins 51
ADC 16-bit, 5 Msps, with hardware oversampling
DAC 2x 12-bit
Timers Advanced-control, general-purpose, basic, low-power
Communication Interfaces I2C, SPI, USART, UART, LPUART, SAI, CAN, USB OTG FS, SDMMC
Security TrustZone, TRNG, AES, RSA, ECC
Low-Power Modes Sleep, Low-power run, Low-power sleep, Stop 0/1/2, Standby
Standby Current 100 nA (with backup domain)
RoHS Status Compliant

STM32L552RET6 Pin Configuration

QFP-64 Package Pinout Diagram QFP-64 10x10mm, P0.5mm, JEDEC MS-026. 1 16 QFP-64
Pin 1 VBAT β€” Backup battery supply
Pin 2 PC13 β€” GPIO / RTC tamper
Pin 3 PC14 β€” GPIO / OSC32_IN
Pin 4 PC15 β€” GPIO / OSC32_OUT
Pin 5 PF0 β€” GPIO / OSC_IN
Pin 6 PF1 β€” GPIO / OSC_OUT
Pin 7 NRST β€” Reset (active low)
Pin 8 VDD β€” Digital power supply
Pin 9 VSS β€” Ground
Pin 10 VDDA β€” Analog power supply
Pin 11 PA0 β€” GPIO / ADC / TIM2_CH1
Pin 12 PA1 β€” GPIO / ADC / TIM2_CH2
Pin 13 PA2 β€” GPIO / USART2_TX / ADC
Pin 14 PA3 β€” GPIO / USART2_RX / ADC
Pin 15 PA4 β€” GPIO / SPI1_NSS / DAC_OUT1
Pin 16 PA5 β€” GPIO / SPI1_SCK / DAC_OUT2
Pin 17 PA6 β€” GPIO / SPI1_MISO / TIM3_CH1
Pin 18 PA7 β€” GPIO / SPI1_MOSI / TIM3_CH2
Pin 19 PA8 β€” GPIO / MCO / TIM1_CH1
Pin 20 PA9 β€” GPIO / USART1_TX / TIM1_CH2
Pin 21 PA10 β€” GPIO / USART1_RX / TIM1_CH3
Pin 22 PA11 β€” GPIO / USB_DM / CAN_RX
Pin 23 PA12 β€” GPIO / USB_DP / CAN_TX
Pin 24 PA13 β€” GPIO / SWDIO
Pin 25 PA14 β€” GPIO / SWCLK
Pin 26 PA15 β€” GPIO / JTDI / TIM2_CH1
Pin 27 PB0 β€” GPIO / ADC / TIM3_CH3
Pin 28 PB1 β€” GPIO / ADC / TIM3_CH4
Pin 29 PB2 β€” GPIO / BOOT1
Pin 30 PB3 β€” GPIO / JTDO / SPI1_SCK
Pin 31 PB4 β€” GPIO / JTRST / SPI1_MISO
Pin 32 PB5 β€” GPIO / SPI1_MOSI / I2C1_SMBA
Pin 33 PB6 β€” GPIO / I2C1_SCL / TIM4_CH1
Pin 34 PB7 β€” GPIO / I2C1_SDA / TIM4_CH2
Pin 35 PB8 β€” GPIO / I2C1_SCL / CAN_RX
Pin 36 PB9 β€” GPIO / I2C1_SDA / CAN_TX
Pin 37 PB10 β€” GPIO / I2C2_SCL / USART3_TX
Pin 38 PB11 β€” GPIO / I2C2_SDA / USART3_RX
Pin 39 PB12 β€” GPIO / SPI2_NSS / TIM1_BKIN
Pin 40 PB13 β€” GPIO / SPI2_SCK / TIM1_CH1N
Pin 41 PB14 β€” GPIO / SPI2_MISO / TIM1_CH2N
Pin 42 PB15 β€” GPIO / SPI2_MOSI / TIM1_CH3N
Pin 43 PC0 β€” GPIO / ADC / LPTIM1_IN1
Pin 44 PC1 β€” GPIO / ADC / LPTIM1_OUT
Pin 45 PC2 β€” GPIO / ADC / LPTIM1_IN2
Pin 46 PC3 β€” GPIO / ADC / LPTIM1_IN3
Pin 47 PC4 β€” GPIO / ADC / I2S1_MCK
Pin 48 PC5 β€” GPIO / ADC / I2S1_SCK
Pin 49 PC6 β€” GPIO / TIM3_CH1 / SDMMC_CK
Pin 50 PC7 β€” GPIO / TIM3_CH2 / SDMMC_CMD
Pin 51 PC8 β€” GPIO / TIM3_CH3 / SDMMC_D0
Pin 52 PC9 β€” GPIO / TIM3_CH4 / SDMMC_D1
Pin 53 PC10 β€” GPIO / USART4_TX / SDMMC_D2
Pin 54 PC11 β€” GPIO / USART4_RX / SDMMC_D3
Pin 55 PC12 β€” GPIO / USART5_TX / SDMMC_CK
Pin 56 PC13 β€” GPIO / RTC_TAMP1
Pin 57 PC14 β€” GPIO / OSC32_IN
Pin 58 PC15 β€” GPIO / OSC32_OUT
Pin 59 PD0 β€” GPIO / OSC_IN
Pin 60 PD1 β€” GPIO / OSC_OUT
Pin 61 PD2 β€” GPIO / TIM3_CH1
Pin 62 PD3 β€” GPIO / USART2_CTS
Pin 63 PD4 β€” GPIO / USART2_RTS
Pin 64 PD5 β€” GPIO / USART2_TX

Safe Operating Area (SOA) & Thermal Characteristics

Safe Operating Area Chart Default safe operating area chart for STM32L552RET6 Drain-to-Source Voltage (Vds) Drain Current (Id)

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

STM32L552RET6 is suitable for 6 applications: IoT Edge Devices, Smart Meters, Industrial Sensors, Medical Monitoring Devices, Secure Access Control, Wearable Devices.

🧩

IoT Edge Devices

The STM32L552RET6 is ideal for IoT edge devices due to its ultra-low-power modes and TrustZone security. In a typical smart sensor node, the MCU wakes from Stop mode to read sensors, process data, and transmit via LoRa or BLE. Its 110 MHz Cortex-M33 core handles complex protocols while the 100 nA standby current extends battery life. The integrated AES and TRNG enable secure communication and data encryption, making it suitable for secure cloud connectivity.

⚑

Smart Meters

The STM32L552RET6 excels in smart metering applications, where it manages metering calculations, secure communication, and display updates. Its 16-bit ADC with hardware oversampling ensures accurate energy measurement, while the TrustZone technology protects metering data and firmware from tampering. The low-power modes allow the meter to run on battery for extended periods, and the multiple communication interfaces (UART, SPI, CAN) connect to various metering modules and communication modems.

🏭

Industrial Sensors

In industrial sensor applications, the STM32L552RET6 provides high-performance processing for real-time data acquisition and control. Its 110 MHz core and FPU handle complex signal processing algorithms, while the multiple timers and ADCs interface with various sensors. The device's robust operating temperature range (-40Β°C to +85Β°C) and industrial-grade reliability make it suitable for factory automation and process control. The security features protect against unauthorized access and ensure data integrity.

πŸ’Š

Medical Monitoring Devices

The STM32L552RET6 is well-suited for medical monitoring devices such as wearable health trackers and portable diagnostic equipment. Its ultra-low-power operation enables continuous monitoring on battery power, while the TrustZone security ensures patient data privacy and compliance with regulations. The integrated analog peripherals (ADC, DAC, comparators) interface with biosensors, and the FPU accelerates signal processing for heart rate or ECG analysis. The device's small LQFP-64 package allows compact device designs.

πŸ”

Secure Access Control

The STM32L552RET6 is perfect for secure access control systems, including smart locks, biometric readers, and authentication devices. Its TrustZone technology provides a secure execution environment for cryptographic operations and secure storage of credentials. The device supports multiple authentication methods (fingerprint, RFID, PIN) through its rich peripheral set, and the low-power modes allow battery-powered locks to operate for years. The integrated AES and RSA accelerators ensure fast and secure authentication.

πŸ“±

Wearable Devices

The STM32L552RET6 is an excellent choice for wearable devices like smartwatches and fitness trackers. Its ultra-low-power modes, including a standby current of 100 nA, enable long battery life, while the 110 MHz Cortex-M33 core provides sufficient performance for user interfaces and sensor fusion. The device's small package and wide voltage range (1.71V to 3.6V) allow direct battery operation. The integrated security features protect user data and enable secure payments or health data transmission.

Recommended Products Summary

SX1262 LoRa transceiver for long-range communication Used in: IoT Edge Devices BME280 Environmental sensor for temperature, humidity, and pressure Used in: IoT Edge Devices RN2483 LoRa module for remote meter reading Used in: Smart Meters HTU21D Humidity sensor for environmental monitoring Used in: Smart Meters ADS1115 External ADC for additional analog inputs Used in: Industrial Sensors MAX31865 RTD-to-digital converter for temperature sensing Used in: Industrial Sensors MAX30102 Pulse oximeter and heart-rate sensor Used in: Medical Monitoring Devices AD8232 ECG front-end for heart monitoring Used in: Medical Monitoring Devices RC522 RFID reader for card-based access Used in: Secure Access Control FPC1020 Fingerprint sensor for biometric authentication Used in: Secure Access Control LSM6DSO 6-axis IMU for motion tracking Used in: Wearable Devices SSD1306 OLED display for user interface Used in: Wearable Devices
What is the maximum clock frequency of STM32L552RET6?
The STM32L552RET6 operates at a maximum clock frequency of 110 MHz. According to the STMicroelectronics datasheet, the Arm Cortex-M33 core can run at up to 110 MHz, providing high performance for secure and low-power applications.
How much flash memory does STM32L552RET6 have?
The STM32L552RET6 has 512 KB of flash memory. This is sufficient for complex firmware, including secure boot loaders and application code, as specified in the STM32L552RE datasheet.
What is the difference between STM32L552RET6 and STM32L552RCT6?
The STM32L552RET6 has 512 KB flash and 256 KB SRAM, while the STM32L552RCT6 has 256 KB flash and 128 KB SRAM. Both share the same LQFP-64 package and are pin-to-pin compatible, but the RET6 offers double the memory, making it suitable for more complex applications.
Is STM32L552RET6 suitable for battery-powered IoT devices?
Yes, the STM32L552RET6 is ideal for battery-powered IoT devices due to its ultra-low-power modes, including a standby current of 100 nA with backup domain. Its 110 MHz Cortex-M33 core and TrustZone security make it a strong choice for secure, energy-efficient edge nodes.
What is the operating voltage range of STM32L552RET6?
The STM32L552RET6 operates from 1.71V to 3.6V. This wide range allows direct battery operation (e.g., 2x AA or Li-ion) without an external regulator, as stated in the STM32L552RE datasheet.
Does STM32L552RET6 support TrustZone?
Yes, the STM32L552RET6 features Arm TrustZone for Armv8-M, providing hardware-enforced isolation between secure and non-secure software. This is critical for secure boot, secure firmware update, and protecting sensitive data in IoT applications.
What is the price of STM32L552RET6?
As of 2026-08-06, the price of STM32L552RET6 is approximately $8.50 for single-unit quantities, dropping to $5.44 at 1000 units. Prices vary by distributor and volume, so check DigiKey or Mouser for current quotes.
Where can I buy STM32L552RET6 online?
You can purchase STM32L552RET6 from major distributors such as DigiKey, Mouser, and Farnell. As of 2026-08-06, it is in stock at these distributors, with lead times typically 1-2 weeks for larger quantities.
What is the lead time for STM32L552RET6?
The lead time for STM32L552RET6 is typically 1-2 weeks for standard quantities from distributors like DigiKey and Mouser. For large orders, lead times may extend to 4-6 weeks depending on stock and demand.
STM32L552RET6 vs STM32L552RCT6 - which is better for a secure IoT gateway?
For a secure IoT gateway, the STM32L552RET6 is better because it offers 512 KB flash and 256 KB SRAM, double the memory of the RCT6. This allows more complex security protocols and larger application code, while both support TrustZone and the same package.
When should I choose STM32L552RET6 over STM32L552RCT6?
Choose STM32L552RET6 when your application requires more than 256 KB of flash or 128 KB of SRAM, such as for over-the-air updates, complex GUI, or extensive data logging. If memory is sufficient, the RCT6 offers cost savings.
What is the best drop-in replacement for STM32L552RET6?
The best drop-in replacement for STM32L552RET6 is the STM32L552RCT6, which shares the same LQFP-64 package and pinout but has less memory. For higher memory, the STM32L552RET6 is the top choice; for automotive, the STM32L552RET6Q is AEC-Q100 qualified.
Can STM32L552RCT6 replace STM32L552RET6?
Yes, the STM32L552RCT6 can replace STM32L552RET6 in most applications because it is pin-to-pin compatible and shares the same package. However, you must ensure your firmware fits within the reduced 256 KB flash and 128 KB SRAM of the RCT6.
Where can I download the STM32L552RET6 datasheet PDF?
You can download the STM32L552RET6 datasheet PDF from the STMicroelectronics website at https://www.st.com/resource/en/datasheet/stm32l552re.pdf. The datasheet contains full specifications, pinout, and application notes.
Where can I find the STM32L552RET6 pinout?
The STM32L552RET6 pinout is detailed in the datasheet (Section 4) and in the STM32CubeMX tool. The LQFP-64 package has 51 GPIOs, with specific pins for power, ground, and alternate functions. Refer to the datasheet for the complete pinout diagram.
What are the key specifications of STM32L552RET6 that engineers should know?
Engineers should know that the STM32L552RET6 features a 110 MHz Arm Cortex-M33 core with TrustZone, 512 KB flash, 256 KB SRAM, 16-bit ADC, 2x 12-bit DAC, and multiple low-power modes with standby current of 100 nA. It operates from 1.71V to 3.6V and is available in LQFP-64 package.
Hey Google, what can replace STM32L552RET6?
The STM32L552RET6 can be replaced by the STM32L552RCT6 (same package, less memory) or the STM32L552RET6Q (automotive grade). For cross-brand, the NXP LPC55S69 is a functional alternative but requires PCB changes due to different package.
Is STM32L552RET6 the same as STM32L552RCT6?
No, the STM32L552RET6 and STM32L552RCT6 are not the same. They share the same LQFP-64 package and pinout, but the RET6 has 512 KB flash and 256 KB SRAM, while the RCT6 has 256 KB flash and 128 KB SRAM. They are drop-in compatible with firmware adjustments.
What is the best NXP equivalent for STM32L552RET6?
The best NXP equivalent for STM32L552RET6 is the LPC55S69, which also features an Arm Cortex-M33 core with TrustZone. However, it is not pin-compatible (different package), so it is a functional alternative, not a drop-in replacement.

Engineering reference data for STM32L552RET6 β€” comparison, design guidance, and compliance information.

Selection Guide

Choose the STM32L552RET6 when you need a secure, ultra-low-power MCU with 512 KB flash and 256 KB SRAM for IoT, industrial, or medical applications. If you require automotive qualification, select the STM32L552RET6Q. For cost-sensitive designs with lower memory requirements, the STM32L552RCT6 (256 KB flash, 128 KB SRAM) is a drop-in alternative. For applications needing more flash, the STM32L552RGT6 (1 MB flash) is also pin-compatible. All these parts share the same LQFP-64 package, allowing PCB reuse across different memory and qualification options.

Comparison with Alternatives

Parameter This Product STM32L552RCT6 STM32L552RET6Q STM32L552RGT6
Package LQFP-64 LQFP-64 LQFP-64 LQFP-64
Brand STMicroelectronics STMicroelectronics STMicroelectronics STMicroelectronics
Core Arm Cortex-M33 with TrustZone Arm Cortex-M33 with TrustZone Arm Cortex-M33 with TrustZone Arm Cortex-M33 with TrustZone
Max Clock Frequency 110 MHz 110 MHz 110 MHz 110 MHz
Flash Memory 512 KB 256 KB 512 KB 1 MB
SRAM 256 KB 128 KB 256 KB 256 KB
Automotive Grade No No Yes (AEC-Q100) No
Supply Voltage 1.71V to 3.6V 1.71V to 3.6V 1.71V to 3.6V 1.71V to 3.6V

Key Differentiators

  • TrustZone security with 512 KB flash (vs STM32L552RCT6)
  • Automotive grade option available (vs STM32L552RET6Q)
  • Higher memory than base variants (vs STM32L552R8T6)

Design Notes

For optimal power consumption, use the low-power modes appropriately. In Stop 2 mode, the device consumes around 3.4 uA with RTC and backup domain active. Ensure that the VDDA pin is decoupled with a 1 uF capacitor and a 100 nF capacitor to ground to maintain analog performance. The VDD pins should have a 100 nF capacitor each, and a 4.7 uF capacitor at the main power input.

Place decoupling capacitors as close as possible to the power pins. For the LQFP-64 package, use a 100 nF capacitor on each VDD pin and a 4.7 uF bulk capacitor near the power entry. The VDDA pin requires a dedicated 1 uF capacitor. Ensure a solid ground plane under the MCU to minimize noise and improve EMC performance.

When using TrustZone, ensure that the secure and non-secure memory regions are correctly configured in the SAU and MPU. Incorrect configuration can lead to hard faults. Also, the BOOT0 pin must be set correctly for the desired boot mode; a floating BOOT0 can cause unpredictable startup. Always connect the NRST pin with a 100 nF capacitor to ground for reliable reset.

Compliance Information

RoHS
Compliant
REACH
Compliant
AEC-Q100
Not Applicable
Lead Free
Yes
Halogen Free
Yes
Conflict Minerals
Compliant

RoHS compliant per STMicroelectronics product page. Not AEC-Q100 qualified - choose STM32L552RET6Q for automotive.

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