STMicroelectronics STM32L073CBU6

Overview

STM32L073CBU6 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller featuring 192 KB Flash with ECC, 20 KB SRAM, 6 KB EEPROM, integrated LCD driver, USB 2.0 (crystal-less), and dual 12-bit DACs - deployed in battery-powered industrial sensors and portable medical monitors requiring sub-1 µA Stop mode operation.

For engineers reviewing the STM32L073CBU6 datasheet, STM32L073CBU6 pinout, STM32L073CBU6 application, or STM32L073CBU6 equivalent, key selection criteria include its 0.86 µA Stop mode + RTC + 20-KB RAM retention, 12-bit ADC at 1.14 Msps (16 channels), and 48 MHz RC self-calibrated for USB timing accuracy without external crystal.

Technical Context

The STM32L073CBU6 implements a dual-bank Flash architecture enabling read-while-write operation and hardware ECC protection, paired with a multi-speed internal RC oscillator suite (MSI: 65 kHz–4.2 MHz; HSI48: factory-trimmed for USB). Its low-power design integrates dynamic voltage scaling and five power modes - including Standby (0.29 µA) and Stop + RTC (0.86 µA) - with fast 5 µs wakeup from Flash.

Peripherals are routed via an interconnect matrix supporting concurrent DMA transfers across ADC, DAC, USART, SPI, I²C, and timers. The device includes a dedicated LCD controller (up to 4×52 segments), two ultra-low-power comparators (down to 1.65 V), and a touch sensing controller (24 channels), all operating within the 1.65–3.6 V supply range and -40 to +125 °C temperature envelope.

Key Specifications

Pinout & Package

STM32L073CBU6 is housed in a 48-pin UFQFPN package (7 × 7 mm, 0.5 mm pitch), optimized for compact, thermally efficient PCB layouts in space-constrained portable devices.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power MCU applications.

Compared with STM32L072CBU6, the STM32L073CBU6 adds USB and LCD functionality at identical footprint; versus STM32L432KCU6, it trades computational headroom for 3.8× lower Stop-mode current - critical for decade-long battery life.

Availability

STM32L073CBU6 is available at Aetrix Electronics and suitable for smart utility meters, portable medical monitors, industrial wireless sensor nodes, and low-power HVAC controllers requiring stable component supply across multi-year production cycles.

Supply support for STM32L073CBU6 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 management ICs, MEMS, and automotive-grade components since 1987.

The STM32L0 series targets ultra-low-power embedded applications - specifically designed for battery-operated and energy-harvesting systems demanding sub-microamp sleep currents and robust analog integration without external support components.

FAQ

What is the maximum operating frequency and core type of the STM32L073CBU6?

The STM32L073CBU6 features an Arm Cortex-M0+ core rated for up to 32 MHz operation, delivering 0.95 DMIPS per MHz. It achieves this frequency using internal oscillators (HSI16 or MSI) or external crystals (HSE up to 25 MHz), with PLL support for higher clock synthesis. All timing specifications - including ADC conversion, USB frame generation, and timer resolution - are validated at this maximum frequency under full voltage and temperature range conditions.

Does the STM32L073CBU6 support USB without an external crystal?

Yes, the STM32L073CBU6 integrates a factory-trimmed 48 MHz HSI48 RC oscillator that is self-calibrated using USB Start-of-Frame (SOF) tokens, eliminating the need for an external 48 MHz crystal. This feature is fully supported in production silicon and documented in Section 3.18.5 of DS10685 Rev 7, enabling reliable USB 2.0 Full-Speed communication in crystal-less configurations.

How much SRAM and EEPROM does the STM32L073CBU6 include, and what are their key reliability features?

The STM32L073CBU6 includes 20 KB of general-purpose SRAM and 6 KB of data EEPROM - both protected by hardware ECC. The EEPROM supports >300,000 write/erase cycles and 20-year data retention at 55 °C, with built-in wear leveling and error correction logic. SRAM retains full contents in Stop mode with RTC active at 0.86 µA, and includes 20 bytes of backup registers preserved in Standby mode.

Which low-power modes are available, and what is the lowest achievable current consumption?

The STM32L073CBU6 offers five low-power modes: Sleep, Low-power Run, Low-power Sleep, Stop, and Standby. The lowest current is 0.29 µA in Standby mode with three wakeup pins enabled and RTC disabled. With RTC and 20 KB SRAM retention active, Stop mode draws 0.86 µA - verified per Table 37 and Table 38 in DS10685 Rev 7 under 1.8 V, 25 °C conditions.