LTC4261/LTC4261-2 Negative Voltage Hot Swap Controllers with 2 ADC and I C Monitoring FEATURES DESCRIPTION TM n Allows Safe Insertion into Live 48V Backplanes The LTC 4261/LTC4261-2 negative voltage Hot Swap n 10-Bit ADC Monitors Current and Voltages controllers allow a board to be safely inserted and removed 2 n I C/SMBus Interface or Single-Wire Broadcast Mode from a live backplane. Using an external N-channel pass n Floating Topology Allows Very High Voltage transistor, the board supply voltage can be ramped at an Operation adjustable rate. The devices feature independently adjust- n Independently Adjustable Inrush and Overcurrent able inrush current and overcurrent limits to minimize Limits stresses on the pass transistor during start-up, input n Controlled Soft-Start Inrush step and output short conditions. The LTC4261 defaults n Adjustable UV/OV Thresholds and Hysteresis to latch-off while the LTC4261-2 defaults to auto-retry on n Sequenced Power Good Outputs with Delays overcurrent faults. n Adjustable Power Good Input Timeout 2 An I C interface and onboard 10-bit ADC allow monitoring n Programmable Latchoff or Auto-Retry After Faults of board current, voltage and fault status. A single-wire n Alerts Host After Faults broadcast mode is available to simplify the interface by n Available in 28-Lead Narrow SSOP and 24-Lead eliminating two optoisolators. (4mm 5mm) QFN Packages The controllers have additional features to interrupt the host when a fault has occurred, notify when output power APPLICATIONS is good, detect insertion of a board and turn off the pass n AdvancedTCA Systems transistor if an external supply monitor fails to indicate n Telecom Infrastructure power good within a timeout period. n 48V Distributed Power Systems L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot n Power Monitors Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 7382167, 8194379, 8230151. TYPICAL APPLICATION 2 48V/200W Hot Swap Controller with I C and ADC 48V RTN Start-Up Behavior 453k 4 1k IN SERIES 1% 1/4W EACH V 48V INPUT IN UV = 38.5V UVL PGI 50V/DIV UV RELEASE 16.9k UVH ALERT AT 43V 1% ADIN2 SDAO V OV = 72.3V OV SDAI + OUT LTC4261CGN + 330F 50V/DIV V IN OV RELEASE INTV SCL CC 100V AT 71V ON ADIN LOAD SENSE PGIO 11.8k 0.5A/DIV PG ON SS TMR EN V SENSE GATE DRAIN RAMP EE 1% V IN 1M 1k 47nF PG 1F 220nF 10 50V/DIV 42612 TA01b 10nF 0.1F 47nF 10ms/DIV 100V 0.008 5% 1% V OUT 48V INPUT 42612 TA01 Q1 IRF1310NS 42612fd 1 For more information www.linear.com/LTC4261LTC4261/LTC4261-2 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) V (Note 3) .......................................... 0.3V to 10.65V Operating Ambient Temperature Range IN Drain (Note 4) .......................................... 0.3V to 3.5V LTC4261C ................................................ 0C to 70C PGI, ON, ALERT, SDAO, SDAI, SCL, ADIN, ADIN2, LTC4261I .............................................40C to 85C OV, SENSE, ADR1, ADR0, FLTIN, TMR, Storage Temperature Range SS, RAMP Voltages ...................0.3V to INTV + 0.3V SSOP ................................................. 65C to 150C CC UVL, UVH, EN ............................................ 0.3V to 10V QFN .................................................... 65C to 125C GATE Voltage .................................. 0.3V to V + 0.3V Lead Temperature (Soldering, 10 sec) IN PG, PGIO Voltages .................................... 0.3V to 80V SSOP Only ........................................................300C Supply Voltage (INTV ) .......................... 0.3V to 5.5V CC PIN CONFIGURATION TOP VIEW 1 PGIO PGI 28 TOP VIEW ON 2 27 PG 3 26 EN ALERT 24 23 22 21 20 SDAO 4 25 ADR1 SDAO 1 19 EN SDAI 5 24 ADR0 SDAI 2 18 ADR1 6 23 ADIN SCL SCL 3 17 ADR0 INTV 7 22 FLTIN INTV 4 25 16 ADIN CC CC UVL 8 21 V IN UVL 5 15 V IN 9 20 TMR UVH 6 14 TMR UVH OV 7 13 SS ADIN2 10 19 SS 8 9 10 11 12 OV 11 18 RAMP 12 17 NC NC V 13 16 DRAIN EE UFD PACKAGE 24-LEAD (4mm 5mm) PLASTIC QFN 14 15 GATE SENSE T = 125C, = 45C/W JMAX JA GN PACKAGE EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB 28-LEAD PLASTIC SSOP T = 125C, = 85C/W JMAX JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4261CGN PBF LTC4261CGN TRPBF LTC4261CGN 28-Lead Plastic SSOP 0C to 70C LTC4261IGN PBF LTC4261IGN TRPBF LTC4261IGN 28-Lead Plastic SSOP 40C to 85C LTC4261CGN-2 PBF LTC4261CGN-2 TRPBF LTC4261IGN-2 28-Lead Plastic SSOP 0C to 70C LTC4261IGN-2 PBF LTC4261IGN-2 TRPBF LTC4261IGN-2 28-Lead Plastic SSOP 40C to 85C LTC4261CUFD PBF LTC4261CUFD TRPBF 4261 24-Lead (4mm 5mm) Plastic QFN 0C to 70C LTC4261IUFD PBF LTC4261IUFD TRPBF 4261 24-Lead (4mm 5mm) Plastic QFN 40C to 85C LTC4261CUFD-2 PBF LTC4261CUFD-2 TRPBF 42612 0C to 70C 24-Lead (4mm 5mm) Plastic QFN LTC4261IUFD-2 PBF LTC4261IUFD-2 TRPBF 42612 24-Lead (4mm 5mm) Plastic QFN 40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: