LTC4258 Quad IEEE 802.3af Power over Ethernet Controller with Integrated Detection FEATURES DESCRIPTIO TM Controls Four Independent 48V Powered The LTC 4258 is a quad 48V Hot Swap controller de- Ethernet Ports signed for use in IEEE 802.3af compliant Power Each Port Includes: Sourcing Equipment (PSE). It consists of four independent IEEE 802 .3af Compliant PD Detection and ports, each with output current limit, short-circuit protec- Classification tion, complete Powered Device (PD) detection and classi- Output Current Limit with Foldback fication capability, and programmable PD disconnect using Short-Circuit Protection with Fast Gate Pull-Down DC sensing. Used with power MOSFETs and passives as PD Disconnect Using DC Sensing in Figure 1, the LTC4258 can implement a complete IEEE Power Good Indication 802.3af-compliant PSE. TM 2 Operates Autonomously or by I C Control The LTC4258 can operate autonomously or be controlled by 4-Bit Programmable Digital Address Allows Control 2 an I C serial interface. Up to 16 LTC4258s may coexist on of Up to 64 Ports the same data bus, allowing up to 64 powered Ethernet ports Programmable INT Pin Eliminates Software Polling to be controlled with only two digital lines. Fault conditions Current and Duty Cycle Limits Protect External FETs are optionally signaled with the INT pin to eliminate software Available in a 36-Pin SSOP Package polling. U APPLICATIO S External power MOSFETs, current sense resistors and di- odes allow easy scaling of current and power dissipation IEEE 802.3af Compliant Endpoint and Midspan levels and provide protection against voltage and current Power Sources spikes and ESD events. IP Phone Systems The LTC4258 is available in a 36-pin SSOP package. DTE Power Distribution , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Linear Technology also provides solutions for 802.3af PD Hot Swap is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. applications with the LTC4257, LTC4257-1, and LTC4267. TYPICAL APPLICATIO 3.3V 0.1F 0.1F 100V X7R INT SHDN1 SHDN2 SHDN3 SHDN4 V AUTO BYP RESET SCL DD SDAIN DETECT1 SDAOUT DETECT2 AD0 DETECT3 LTC4258 0.1F 100V SMAJ58A CMPD3003 AD1 4 4 4 AD2 DETECT4 AD3 DGND AGND V SENSE1 GATE1 OUT1 SENSE2 GATE2 OUT2 SENSE3 GATE3 OUT3 SENSE4 GATE4 OUT4 EE 10k 10k 10k 10k R S1 48V PORT1 Q1 R S2 0.1F PORT2 Q2 R S3 PORT3 Q3 R S4 PORT4 4258 F01 Q4 RS1 TO RS4: 0.5 Q1 TO Q4: IRFM120A Figure 1. Complete 4-Port Powered Ethernet Power Source 4258fb 1 U ULTC4258 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW Supply Voltages ORDER PART 1 36 NC RESET V to DGND .......................................... 0.3V to 5V NUMBER DD BYP 2 35 AUTO V to AGND ......................................... 0.3V to 70V EE INT 3 34 OUT1 LTC4258CGW 4 GATE1 DGND to AGND (Note 2) ................................. 0.3V SCL 33 SDAOUT 5 32 SENSE1 Digital Pins 6 31 OUT2 SDAIN SCL, SDAIN, SDAOUT, INT, AUTO, RESET AD3 7 30 GATE2 8 29 SENSE2 SHDNn, ADn ................. DGND 0.3V to DGND + 5V AD2 AD1 9 28 V EE Analog Pins AD0 10 27 OUT3 GATEn (Note 3) ................... V 0.3V to V + 12V 11 GATE3 EE EE DETECT1 26 DETECT2 12 25 SENSE3 DETECTn .................... DGND 21V to DGND + 0.3V 13 24 OUT4 DETECT3 SENSEn ................................. V 0.3V to V + 1V EE EE DETECT4 14 23 GATE4 OUTn .................................... V 70V to V + 70V 15 22 SENSE4 EE EE DGND V 16 21 AGND BYP Current ................................................. 0.1mA DD 17 20 SHDN4 SHDN1 Operating Ambient Temperature Range ...... 0C to 70C SHDN2 18 19 SHDN3 Junction Temperature (Note 4)............................ 150C GW PACKAGE 36-LEAD PLASTIC SSOP Storage Temperature Range ................ 65C to 150C T = 150C, = 80C/W JMAX JA Lead Temperature (Soldering, 10 sec)................. 300C Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: