The Tech Blog

This bit of tech was one of the most key innovations which made Bluetooth audio good. Classic Bluetooth audio sounded OK, but drained battery quickly and sometimes lagged behind video. Bluetooth Low Energy (BLE) solved power issues, but wasn’t originally built for audio. Early BLE couldn’t ensure packets arrived exactly when needed, leading to dropouts, delays, or distorted sound. We needed a reliable, low-latency audio without sacrificing battery life. That’s why Bluetooth LE Audio was introduced along with BLE v5.2 spec.

Think of Isochronous Adaptation Layer(ISOAL) as the invisible worker organizing audio packets to ensure they’re delivered precisely on time. It acts as a bridge between your audio source, like a smartphone, and the wireless radio inside your headphones/earbuds.

Before ISOAL existed, audio streams had to cram large chunks into single packets, causing inflexibility and interruptions. Synchronizing stereo earbuds was difficult because packets weren’t always perfectly timed. ISOAL fixes these issues, enabling smooth stereo playback and synchronized sound across multiple devices without lag or glitches.

So how does it actually work? When your phone streams audio, it hands complete chunks (called Service Data Units, or SDUs) to ISOAL. If these chunks are too large for transmission, ISOAL breaks them into smaller pieces. It labels each smaller piece (called Protocol Data Units, or PDUs) with precise timestamps and sequence numbers. These labels act as detailed instructions, so your earbuds know exactly when to reconstruct and play the audio smoothly.

In summary, ISOAL ensures perfect audio sync between left and right earbuds. BTW, ISOAL is implemented entirely in the controller’s firmware and doesn’t need any additional hardware or app firmware coding. Its timestamps are in the microsecond range, ensuring precision. ISOAL handles both Connected Isochronous Streams (CIS) for point-to-point audio (true-wireless earbuds) and Broadcast Isochronous Streams (BIS) for one-to-many audio.

Happen to run across this relatively new breakthrough in battery tech and spend time exploring it further yesterday. Some of you may have heard of Silicon Carbon Batteries being used in flagship phones with charger battery capacities. I think it could change how we store energy.

The key difference between SiC and normal lithium battery is in their anode composition. In a normal lithium-ion battery, lithium ions move in and out of graphite anode layers in a process called intercalation. In a silicon-carbon cell, tiny silicon particles sit inside a carbon structure and form alloys with lithium. This packs in far more Li ions than graphite. Meaning more energy density.

Theoretically, Graphite anode delivers around 372mAh/g. Silicon one can store up to 3,600 mAh/g(10x). But pure Si expand to 300-400% when battery is charged and contracts when discharged. This repeated size variation can cause the electrode to break down and not be useful in a battery. To confine this swelling, usually Silicon is coated with conductive carbon in SiC Batteries. There are also other secret sauces at play. So while we don’t get full 10x gains, we still achieve much higher capacity, boosting energy density from ~300 Wh/kg(normal) to ~450 Wh/kg(SiC).

These cells deliver higher energy for the same weight, making them ideal for both smartphones and EVs. They also charge faster, cutting down wait times significantly. With greater capacity per charge, devices need fewer charge cycles, which helps extend overall battery lifespan. It also means thinner, lighter batteries for the same performance.

In EVs, carmakers are testing them to push range to current max ranges or to cut pack weight. Stationary storage makers are looking at them for grid support, where extra energy and longer life helps cuts system costs. Chinese phone players are already using them, EV folks like Benz is considering them for their electric EVs. I think this tech will be mainstream in cars, phones, and home storage in the next 2-4yrs.