Single-cell (1S) battery laptops are having a moment. By cutting the battery pack down to one cell instead of two or three in series, OEMs can lower system BOM cost and simplify the power architecture — fewer cells to balance, fewer protection components, and a lighter, thinner design overall. It’s no surprise more thin-and-light and budget-friendly laptops are adopting this approach.
But the 1S architecture comes with a catch that doesn’t show up on a spec sheet until you start measuring battery life: the LED backlight driver for the LCD display becomes noticeably less efficient. The reason is straightforward. A 1S cell sits at a lower voltage than a 2S or 3S pack, which means the boost converter driving the LED backlight has to work across a much larger voltage conversion ratio to reach the LED string voltage. Bigger conversion ratios mean bigger losses — and on a single cell, there’s nowhere for that inefficiency to hide.
This problem is getting worse, not better, for an ironic reason: the rest of the system is improving. SoCs, memory, and other platform components keep getting more power-efficient, especially in low-power standby modes. As those components shrink their share of total power draw, the display — and specifically the LED backlight driver — stands out even more. In many modern designs, the display now accounts for as much as 70% of total system power. What used to be one power consumer among many is now, by far, the biggest one.
That makes backlight driver efficiency a first-order design decision, not an afterthought. This is exactly where pSemi’s ARC1C0608 comes in. It’s purpose-built for this exact challenge:
- Full 1S battery range support — it operates cleanly across the entire discharge curve of a single cell, from full charge down to cutoff, without efficiency collapsing at the low end.
- Peak efficiency >94% — even with the larger conversion ratio inherent to 1S systems.
- Parallel-able architecture — multiple ARC1C0608 devices can be combined to drive the higher LED currents needed for high-resolution, high-brightness displays, without sacrificing efficiency as brightness scales up.
Figure 1. ARC1C0608 Efficiency vs IOUT in parallel operation
Figure 1 shows the 2pcs parallel ARC1C0608 efficiency in 10P8S LED configuration at different battery voltages. The peak efficiency is >94% with a very tight efficiency gap between different voltages.
The efficiency number matters more than it might seem. Going from a typical competing solution to >94% efficiency roughly cuts backlight power losses in half. Since the backlight is now the single largest power draw in the system, that kind of loss reduction translates directly into real, noticeable battery life — often an extra hour of runtime with no other changes to the platform.
As 1S battery designs continue to spread across the laptop market, the LED backlight driver is quickly becoming the component that separates a good battery life story from a great one. Solutions like the ARC1C0608 show that you don’t have to trade off BOM savings and simplicity for runtime — with the right driver, you can have both.
Please visit https://psemi.com/products/power-management/led-boost-arc1c0608-arc1c0605/ to learn more about ARC1C0608.
Please contact Sales@psemi.com for any questions.