em | bleu Sets Global Benchmark for Ultra-Low-Power Bluetooth® LE Performance
EM Microelectronic announced that its em | bleu (EM9305) Bluetooth® Low Energy System-on-Chip has achieved the top ranking in the inaugural BlueJoule benchmark, an open, reproducible framework designed to measure real-world Bluetooth® advertising energy efficiency.
With this result, em | bleu establishes a new reference point for ultra-low-power Bluetooth® designs, delivering up to twice the autonomy of competing solutions in representative always-on sensor and real-time tracking scenarios.
Battery life: the critical IoT viability factor
Across medical, industrial, and retail IoT deployments, battery life has become the single most important design constraint. Limited autonomy leads to costly maintenance cycles, device returns, and battery replacement logistics that can exceed the cost of the device itself.
For Bluetooth® Low Energy sensors that spend more than 99% of their time in sleep mode between transmissions, even microamp-level reductions directly translate into months, or years, of added operating life.
Objective, reproducible comparison across vendors
Developed by Bob Frankel (EM Foundation) and Mohammad Afaneh (Novel Bits), BlueJoule provides objective, reproducible testing that finally gives the industry true comparison across vendors.
Unlike datasheet values captured in ideal laboratory conditions, BlueJoule is designed to be repeatable and verifiable, enabling engineers to evaluate “real-world” Bluetooth® efficiency on a consistent basis.
Standout performance in typical IoT advertising use cases
In BlueJoule’s inaugural ranking, em | bleu leads across both major advertising profiles:
Always-on sensors using longer advertising intervals representative of “broadcast and sleep” devices
Real-time asset tracking using more frequent advertising intervals that demand higher update rates
BlueJoule expresses results in EM•eralds, where one point corresponds to approximately one month of operation from a CR2032 coin cell, making the benchmark intuitive for product teams estimating autonomy in the field.
Benefits across four high-impact markets
The energy gains demonstrated by em | bleu translate into immediate system-level advantages:
Medical and healthcare sensors: Longer runtimes on compact batteries reduce replacement frequency, simplify workflows, and improve patient compliance, especially for disposable or semi-disposable monitoring patches.
Wearables: Manufacturers can extend runtime significantly without changing battery size, or preserve existing runtimes while reducing thickness, an advantage in tightly constrained industrial design.
Retail (ESL): Multi-year button-cell operation improves the economics of large-scale electronic shelf label deployments, where maintenance costs can dominate total cost of ownership.
Smart home and controls: True “fit-and-forget” sensors and remotes become practical, with the added potential for energy-harvesting designs enabled by operation down to 1.1V.
Designed for sleep-first efficiency
em | bleu’s leadership comes from architectural choices optimized for the reality of IoT: long sleep periods punctuated by brief radio events. While many Bluetooth® solutions focus on active-mode efficiency, em | bleu targets the dominant energy driver in sensors, sleep current, achieving 0.5 μA sleep current with full RAM retention, well below typical industry ranges.
At the core is the Synopsys ARC EM7D ultra-low-power 32-bit processor, paired with a sophisticated multi-mode power management system that dynamically powers only what’s needed. A flexible DC-DC converter supports operation from 1.1V to 5V, with optimized support for common 1.5V and 3V battery architectures.
Proven at scale and built for the smallest designs
The BlueJoule results reinforce what customers have seen in production across more than 500 million deployed devices, including em | bleu’s predecessor in the field.
EM9305 also enables new product categories through extreme miniaturization: its 1.8 × 1.8 mm WLCSP footprint supports space-constrained applications such as smart rings, pens, jewelry, hearing aids, and emerging medical form factors where board area is a primary constraint.
Availability and ecosystem
The em | bleu (EM9305) is in volume production and available through EM Microelectronic’s global distribution network. It supports Bluetooth® Core 5.4, including LE 2M PHY, LE Coded PHY, Direction Finding, and features supporting PAwR and ESL applications.
Development support includes the em | bleu DVK, software development kit, certification support, and full technical documentation via EM Microelectronic’s developer resources.
Want to reduce maintenance and total cost of ownership at scale? Contact EM Microelectronic to discuss your application and evaluate EM9305.