STMicroelectronics Brings New 100W Power-over-Ethernet Standard to Connectivity and Smart-Building Applications
Geneva, April 3, 2019 -- A new chipset from STMicroelectronics lets users quickly build reliable and space-efficient Powered Devices (PDs) to take advantage
Geneva, April 3, 2019 -- A new chipset from STMicroelectronics lets users quickly build reliable and space-efficient Powered Devices (PDs) to take advantage of the latest IEEE 802.3bt Power-over-Ethernet (PoE) specification.
The PM8804 and PM8805 provide the PoE-converter circuitry for PDs up to class-8, which defines a usable power budget of 71 Watts. The chipset saves space, enhances reliability, and cuts time to market for next-generation connectivity equipment including 5G “small cells,” WLAN access points, switches, and routers. ST’s new PoE chipset also targets smart-building and smart-office applications such as IP cameras, access-control systems, display panels, lighting, curtain or shutter controllers, video-call systems, IP phones, and tabletop consoles.
The PM8804 implements a complete PWM controller for a 48V isolated flyback or forward converter, including dual low-side gate drivers for high-efficiency forward active-clamp topologies. The operating frequency is selectable up to 1MHz, allowing the use of small external filter and decoupling components for high power density. Also featuring a high-voltage start up regulator with 20mA output capability, the PM8804 helps save on board space and bill of materials.
The PM8805 companion chip contains two active bridges, a charge pump for driving high-side MOSFETs, a hot-swap FET, and the IEEE 802.3bt compliant interface. Integrating the active bridges saves the real-estate otherwise occupied by eight discrete MOSFETs and their driving circuitry. The PM8805 generates a Power-good signal for enabling the PM8804 and other circuitry such as an LED driver, and supports Maintain Power Signature (MPS) current control that allows the PD to enter power-saving standby without being disconnected.
Both devices are in production now. The PM8804 is packaged as a 3mm x 3mm, 0.5mm-pitch VFQFPN-16.
ST is a global semiconductor leader delivering intelligent and energy-efficient products and solutions that power the electronics at the heart of everyday life. ST’s products are found everywhere today, and together with our customers, we are enabling smarter driving and smarter factories, cities, and homes, along with the next generation of mobile and Internet of Things devices. By getting more from technology to get more from life, ST stands for life.augmented.