STMicroelectronics BLUENRG-345AC

Overview

BLUENRG-345AC from STMicroelectronics is a programmable Bluetooth® Low Energy 5.2 System-on-Chip integrating an Arm® Cortex®-M0+ core (64 MHz), 256 KB flash, 64 KB RAM, and a dedicated BlueNRG radio coprocessor. It delivers -104 dBm RX sensitivity at 125 kbps (Coded PHY), +8 dBm programmable TX output, and supports up to 128 simultaneous BLE connections in industrial automation, smart lighting, and medical wearables.

For engineers reviewing the BLUENRG-345AC datasheet, BLUENRG-345AC pinout, BLUENRG-345AC application, or BLUENRG-345AC equivalent, key selection criteria include its dual-role BLE 5.2 stack support, ultra-low power DEEPSTOP mode (0.6 µA with external LSE), integrated SMPS regulator, hardware AES-128 and PKA accelerators, and QFN48 package compatibility with industrial temperature range (-40 °C to +105 °C).

Technical Context

The BLUENRG-345AC implements a partitioned BLE 5.2 protocol stack: time-critical layers (PHY, LL, HCI) handled by the BlueNRG core coprocessor (DMA-based), while non-critical layers (host stack, profiles) run on the Cortex-M0+. Its RF subsystem uses a low-IF receiver architecture with integrated balun and supports Coded PHY for long-range operation.

Power management combines an embedded SMPS (1.2–1.9 V output), MLDO, LPREG, and RFLDO domains to enable fine-grained voltage scaling across operating modes-SHUTDOWN (10 nA), DEEPSTOP (0.6 µA), and RUN (18 µA/MHz)-with retention control per SRAM bank and configurable wake-up sources including RTC, GPIOs, and BLE radio events.

Key Specifications

Pinout & Package

BLUENRG-345AC is housed in a VFQFPN48 (6 × 6 mm) package with exposed thermal pad, supporting up to 32 fast I/Os (28 with wake-up capability, 31 5 V tolerant), and requiring VSSRF pins connected to ground plane per STMicroelectronics layout guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Bluetooth Low Energy SoC applications.

Compared with nRF52840 and CC2642R, BLUENRG-345AC uniquely balances ultra-low DEEPSTOP current (0.6 µA), hardware PKA for ECDH, and Coded PHY-optimized RF front-end-making it optimal for battery-constrained, security-sensitive, long-range industrial and medical BLE endpoints where firmware size and cryptographic latency matter.

Availability

BLUENRG-345AC is available at Aetrix Electronics and suitable for industrial sensor nodes, smart lighting hubs, fitness trackers, and connected medical patches requiring stable component supply across extended product lifecycles.

Supply support for BLUENRG-345AC 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, designing and manufacturing microcontrollers, power ICs, sensors, and wireless SoCs for industrial, automotive, and consumer markets.

The BlueNRG-LP product line targets ultra-low-power wireless applications demanding BLE 5.2 compliance, cryptographic security, and extended battery life-specifically engineered for industrial IoT edge nodes and regulated medical wearables.

FAQ

What is the maximum number of simultaneous BLE connections supported by BLUENRG-345AC?

The BLUENRG-345AC supports up to 128 physical BLE connections in concurrent master/slave roles. This is enabled by its dedicated BlueNRG core coprocessor handling link-layer timing, freeing the Cortex-M0+ to manage higher-layer stack functions and application logic without connection count bottlenecks.

Does BLUENRG-345AC require an external crystal oscillator for BLE operation?

Yes, BLUENRG-345AC requires a 32 MHz crystal oscillator for BLE radio timing accuracy and a 32 kHz crystal for RTC and low-power mode timing. Both are supported with integrated trimming capacitors, eliminating external load capacitors for the 32 MHz crystal and reducing BOM count.

How does the integrated SMPS improve power efficiency compared to LDO-only operation?

The integrated SMPS reduces active-mode power consumption by ~30% versus LDO operation at 3.3 V supply, delivering 1.2–1.9 V to digital domains. It operates at 4 MHz or 8 MHz and can be disabled for low-voltage (<2.0 V) or low-complexity designs, with automatic bypass mode ensuring seamless transition between SMPS and LDO regulation.

Can BLUENRG-345AC operate as both a BLE central and peripheral simultaneously?

Yes, BLUENRG-345AC supports simultaneous central and peripheral roles via hardware-assisted multi-role operation. The BlueNRG core coprocessor manages concurrent connections, allowing one instance to act as a sensor peripheral while another serves as a gateway central-critical for mesh proxy nodes and wearable-to-smartphone bridging.