DA14695 vs STM32WB55

DA14695 vs STM32WB55: Dialog Wearable SoC vs. ST Dual-Core Wireless MCU

The DA14695 and STM32WB55 are both capable BLE SoCs with Cortex-M application cores, but they approach wireless integration from different angles: DA14695 integrates wearable-specific peripherals, while STM32WB55 integrates the full STM32 peripheral ecosystem alongside a dual-core wireless architecture.

Overview

DA14695 from Dialog Semiconductor targets wearable applications with a 96 MHz Cortex-M33, integrated PMU, QSPI interface, USB 2.0, I²S audio, display controller, capacitive touch, and BLE 5.1 radio. It is the most peripheral-rich BLE SoC for wearable designs in Dialog's portfolio.

STM32WB55 from STMicroelectronics uses a dual-core design: a 64 MHz Cortex-M4 for user applications and a 32 MHz Cortex-M0+ running ST's wireless firmware (BLE 5.0 + IEEE 802.15.4 for Thread/Zigbee). The M4 application core has access to the full STM32 peripheral set — including USB 2.0 FS, LCD controller, SAI audio interface, 12-bit ADC, timers, and hardware crypto — within a 1 MB flash / 256 KB SRAM envelope. STM32WB55 is fully compatible with STM32CubeIDE and the HAL/RTOS middleware ecosystem.

Key Differences

• Core architecture: STM32WB55 uses M4 + M0+ dual-core (application + radio isolation); DA14695 uses single M33 with radio subsystem.
• Flash: STM32WB55 has 1 MB flash; DA14695 has 512 KB on-chip plus QSPI external memory.
• SRAM: DA14695 has 512 KB SRAM; STM32WB55 has 256 KB total (split across application and radio domains).
• PMU: DA14695 integrates a full multi-rail PMU; STM32WB55 requires external power management ICs.
• 802.15.4 / Thread: STM32WB55 supports Thread and Zigbee via the M0+ radio core; DA14695 is BLE 5.1-only.
• USB: Both integrate USB 2.0 FS.
• STM32 ecosystem: WB55 benefits from STM32CubeIDE, HAL drivers, and FreeRTOS/ThreadX middleware; DA14695 uses Dialog's SmartSnippets Toolbox.
• Wearable focus: DA14695's PMU, display controller, and touch integration are wearable-specific; STM32WB55 is a general-purpose wireless MCU.

Use Cases

DA14695 Excels At

Wearable consumer electronics where integrated power management of display, touch, audio, sensors, and radio on a single chip reduces BOM complexity. A smartwatch designed around DA14695 avoids several external power management ICs, simplifying PCB layout and reducing component count.

Medical wearables requiring coordinated power domain control — ensuring the display backlight powers down when the device sleeps while keeping the heart rate sensor and BLE radio active — leverage DA14695's PMU for this coordination in hardware.

STM32WB55 Excels At

STM32-ecosystem products with wireless extension — devices built on existing STM32 designs that need wireless capability added. A team with STM32-based industrial controller firmware can add BLE commissioning and Thread mesh by migrating to STM32WB55 with minimal code changes to the application layer.

Multi-protocol smart home devices needing both BLE and Thread/Zigbee — STM32WB55's M0+ radio core supports both protocols in a way DA14695 cannot, making it suitable for Zigbee-to-BLE bridges and Thread-enabled accessories.

USB HID BLE dongles leveraging STM32WB55's USB 2.0 FS alongside BLE to create PC-connected wireless bridges for keyboards, mice, or sensor data collection.

Verdict

DA14695 is the superior choice for wearable products where integrated PMU, display controller, capacitive touch, USB 2.0, and 512 KB SRAM are all required simultaneously. The PMU alone — managing independent voltage rails for display, sensor, audio, and radio from a single rechargeable lithium cell — replaces two or three external PMIC components that would otherwise add PCB area, design complexity, and firmware interaction challenges. For smartwatches, fitness bands, and medical wearables, DA14695's peripheral set is the most complete single-chip solution available.

STM32WB55 is the better choice for STM32-ecosystem teams extending existing product lines with wireless capability, for products requiring multi-protocol (BLE + Thread/Zigbee) operation in a single chip, or for applications needing USB BLE dongles and PC-connected wireless bridges. Its 1 MB flash supports larger firmware images and A/B OTA partitions. The STM32 middleware ecosystem — FreeRTOS, ThreadX, CMSIS-DSP, USB device library — provides production-tested firmware modules that reduce time-to-market for complex applications. Teams already skilled in STM32 will find STM32WB55 a lower-risk wireless extension of familiar architecture than adopting Dialog's separate toolchain.

The BLE version difference (5.0 on WB55 vs. 5.1 on DA14695) is minor for most applications. The protocol difference (BLE + 802.15.4 on WB55 vs. BLE-only on DA14695) is major — it determines whether the device can join Thread or Zigbee networks at all.