Power adapters and chargers for consumer applications typically consist of transformers and other passive components, connected to active components on a board to convert the incoming AC signal to a regulated output voltage. AmberSemi, a fabless semiconductor company based in Dublin, California, is working on technologies to digitalize the sense, control, and power conversion of the incoming AC power with solid-state silicon-based solutions.
AmberSemi has worked on three aspects in digital control and conversion of incoming AC power: AC Direct DC Enabler, AC Direct Sensing, and AC Switch Controller.
AC Direct DC Enabler
This is a miniature, single silicon-chip–based AC/DC power converter with a topology that is neither a linear switch nor a switch-mode power supply. It’s a novel method for power conversion directly from the AC mains, eliminating transformers, rectifiers, and bulky electrolytics. The technology used in this single-chip converter, which is based on several of their patents, provides several advantages over conventional approaches. Below are some of its characteristics:
- Small footprint: Figure 1 shows a comparison between a conventional power supply board versus AmberSemi’s single-chip solution. Almost all products today need some sort of DC power to run the control logic in a microcontroller that dictates how a device should operate. AmberSemi’s reduction in size allows more components, such as IoT connectivity, sensors, and additional features to be added to products within the same footprint of conventional product form factors. Some product implementation examples include smoke detectors, thermostats, appliances, security products, smart blinds, and even products like light switches and dimmers that are constrained to a single gang box. This reduction in size also allows for the creation of slimmer product form factors that can easily fit in constrained spaces like a light switch.
- Programmability: The DC output is programmable from 2.5 V to 24 V.
- Input/output specifications: The AC input can be from 45 V to 240 V RMS. Output DC power drive is available to a maximum of 5 W, sufficient to control cameras, doorbells, thermostats, microcontroller application boards, and other consumer devices. Figure 2 compares the regulation overload switching between the AmberSemi Direct DC Enabler and a conventional, commercially available supply. Regulation is within 10 mV during steady-state operation for loads ranging from 0.25 W to 5 W at the standard 120-V and 240-V AC inputs for the AmberSemi Direct DC Enabler, which compares favorably to the greater-than-150-mV ripple seen on the competitor product.
The AmberSemi Direct DC Enabler achieves an efficiency of 80% at full load, which also compares well with the 66% to 74% efficiency achieved by conventional, competitive products.
Read the actual article at Power Electronics News: