Si3459 OCTAL IEEE 802.3AT POE PSE CONTROLLER Features Octal-Port Power Sourcing Maskable interrupt pin Equipment (PSE) controller Comprehensive fault protection IEEE 802.3at Type I and II circuitry includes: compliant Power undervoltage lockout Output current limit and short- Port priority shutdown control circuit protection Adds enhanced features for Thermal overload detection maximum design flexibility: Pin-programmable AUTO modes Per-port current and voltage Ordering Information: Extended operating temp range: monitoring See page 49. 40 to +85 C PoE+ support with programmable current limits 56-pin QFN package Multi-point detection (RoHS-compliant) Programmable power MOSFET On-chip dc-dc converter enables gate drive control single-rail power operation Configurable watchdog timer enables failsafe operation Applications IEEE Power Sourcing Equipment IP Phone Systems (PSE) Smartgrid Switches Power over Ethernet Switches Ruggedized and Industrial Switches Description The Si3459 is a fully-programmable, eight-port power management controller for IEEE 802.3 compliant Power Sourcing Equipment (PSE). Designed for use in PSE endpoint (switches), the Si3459 integrates eight independent ports, each with IEEE-required powered device (PD) detection and classification functionality. In addition, the Si3459 features a fully-programmable architecture that enables powered device (PD) disconnect using a dc sense algorithm, a robust multipoint detection algorithm, software-configurable per-port current and voltage monitoring, and programmable current limits to support the IEEE 802.3at standard. Intelligent protection circuitry includes input undervoltage detection, output current limit, and short-circuit protection. The Si3459 operates by 2 host processor control through a three-wire, I C-compatible serial interface. Independent serial data input and output pins enable high- voltage isolation through external isolators. An interrupt pin is used to alert the host processor of various status and fault conditions. The device also supports pin-programmable AUTO modes for autonomous operation, without the need for a host processor. The Si3459 also features an on- chip dc-dc converter for creating the digital voltage rail from the PoE voltage, thus enabling single-rail power operation. Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com Rev. 1.2 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice August 10, 2021 Si3459 Functional Block Diagrams VPWR MCU HVIO Detect Xn (/4) SHDN (+52 V) SPI n SCL Detect HV Drive C8051 SDAI Drive SIO Control SRAM MCU Core SDAO A1 Detection MUX OTP A2 A3 A4 n 2 INT n POR WDT RESET Measure (x2) Gate 50MHz TIMERS AUTO Measure n Drive Xn AMUX 2 Gate PGA Drive ADrC AMUX 10 Bit 500Khz Temp DC-DC Bandgap n Sensor Controller VDD AGND VDDA DG ND CA P DCE N SWO SENSEn GATEn DRA I Nn KSENS x VDD (+3.3V) Rs n 0.25 V DRAINn (NOTE: Only one port shown) DC-DC Converter Block Diagram VPWR VDDA 3.3V CAP 4.3V Regulator DCEN ISENSE SWO AGND The case shown has both the DC-DC converter and series regulator enabled. To enable ONLY the series regulator, tie SWO to VPWR. External components are unnecessary. 2 Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com Rev. 1.2 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice August 10, 2021 V PORTn (V VPWR) DRAINn