19 12 11 20 10 21 9 22 8 23 7 24 Si3484 64-PORT POE POWER MANAGEMENT CONTROLLER Features Pin Assignments 24-Pin QFN Enables use of smaller power Supports classification-based and supplies for up to 64-port PoE LLDP power negotiation systems with Si3459 and Si3454 Supports individual port priority and PSE Controller ICs port configuration Can operate with or without a host Supports Power supply status from 1 MISO 18 SDA Configuration save capability up to 3 power supplies 2 SCK 17 SCL Pin-selectable SPI or UART interface 24-pin Quad flat pack package GND 3 16 BAUD0 Top View Pin-selectable UART data rate 4x4 mm PCB footprint RoHS (Pads on Bottom of Package ) VDD 4 15 BAUD1 complaint Fully-compliant with IEEE 802.3-AT 5 RST 14 RSVD Types I and II Extended temperature operating range (40 to +85 C) 6 RSVD 13 PSLCT Applications Power over Ethernet Endpoint Industrial automation systems switches and Midspans Networked audio See5. Pin Description on page 45. Supports high-power PDs, such as: IP Phone Systems and iPBXs Pan/Tilt/Zoom security cameras Wireless Access Points Security and RFID systems Description The Si3484 is a power manager intended for use with the Si3459 Power over Ethernet (PoE) Power Sourcing Equipment (PSE) controllers for power management of up to 64 ports with three power sources. The Si3459 is capable of delivering over 30 W per port, which means that, in a 24- or 48-port system, a very large power supply would have to be used to avoid overload. Typically, not all ports are used at full power so, a smaller power supply can be used along with the Si3484 power management controller. Use of the Si3484 power manager greatly simplifies system implementation of power management. The Si3484 power management controller is programmed via a SPI or UART interface to set the system power supply capacity, the port power configuration (Type 1: 15.4 W, or high-power Type 2: 30 W) ports, the port priority, the detection timing (Alternative A or Alternative B), and the fault recovery protocol. Once programmed, the configuration data can be saved, and the Si3484 can work without host intervention. Port and overall status information is available and continuously updated. The Si3484 uses the real-time overload and current monitoring capability of the Si3459 to manage power shared among up to 64 ports. Power management is selectable between grant-based or consumption-based algorithms in order to supply power to the greatest number of ports. In high-reliability systems, multiple power supplies are often connected to provide redundancy, which further increases the power supply monitoring requirements. The Si3484 can manage up to three power supplies automatically, enabling or disabling ports in priority order. Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com Rev. 1.0 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice August 5, 2021 MOSI RESET PSE RSVD NSS RSVD TX RX PS3 RSVD PS2 PS1 INTSi3484 Functional Block Diagram Si3484 Application Diagram MCU or Host Controller UART or SPI Si8631 Digital Isolator Select UART or SPI Power Supply Present Si3484 Power Management UART Power Supply 1 Controller Baud Rate Power Supply 2 2 I C Power Supply 3 Power Si3459 Port Controller Si3459 Port Controller Si3459 Port Controller PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD PD 2 Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com Rev. 1.0 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice August 5, 2021