LT1641-1/LT1641-2 Positive High Voltage Hot Swap Controllers DESCRIPTIO FEATURES TM Allows Safe Board Insertion and Removal from a The LT 1641-1/LT1641-2 are 8-pin Hot Swap control- Live Backplane lers that allow a board to be safely inserted and removed Controls Supply Voltage from 9V to 80V from a live backplane. Using an external N-channel pass Programmable Analog Foldback Current Limiting transistor, the board supply voltage can be ramped up at High Side Drive for an External N-Channel a programmable rate. A high side switch driver controls an Latched Operation Mode (LT1641-1) N-channel gate for supply voltages ranging from 9V to Automatic Retry (LT1641-2) 80V. User Programmable Supply Voltage Power-Up Rate The chips feature a programmable analog foldback cur- Undervoltage Lockout rent limit circuit. If the chips remain in current limit for Overvoltage Protection more than a programmable time, the N-channel pass Both are available in 8-Lead SO Package transistor is either latched off (LT1641-1) or is set to U automatically restart after a time-out delay (LT1641-2). APPLICATIO S The PWRGD output indicates when the output voltage, Hot Board Insertion sensed by the FB pin, is within tolerance. The ON pin Electronic Circuit Breaker provides programmable undervoltage lockout. Industrial High Side Switch/Circuit Breaker The LT1641-1/LT1641-2 are available in the 8-lead SO 24V/48V Industrial/Alarm Systems package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATIO 24V Input Voltage Application R Q1 S 0.01 IRF530 V IN V OUT 24V D1 C L CMPZ R1 R5 R3 SHORT 5248B 49.9k 10 59k PIN 1% 5% 1% C1 R6, 10nF 1k, 5% R7 24k V SENSE GATE 5% CC *SMAT70A ON FB R4 3.57k LT1641-1/LT1641-2 1% R2 3.4k 1% PWRGD PWRGD TIMER GND C2 0.68F GND *DIODES, INC. 1641-1 TA01 164112fc 1 U ULT1641-1/LT1641-2 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW Supply Voltage (V ) ...............................0.3V to 100V CC ON 1 8 V CC Input Voltage (SENSE).............................0.3V to 100V FB 2 7 SENSE Input Voltage (TIMER) ...............................0.3V to 44V PWRGD GATE 3 6 Input Voltage (FB, ON)...............................0.3V to 60V GND 4 5 TIMER Output Voltage (PWRGD) ........................0.3V to 100V S8 PACKAGE 8-LEAD PLASTIC SO Output Voltage (GATE) ............................0.3V to 100V T = 125C, = 110C/W JMAX JA Operating Temperature Range ORDER PART NUMBER S8 PART MARKING LT1641-1C, LT1641-2C ........................... 0C to 70C LT1641-1CS8 16411 LT1641-1I, LT1641-2I ........................ 40C to 85C LT1641-1IS8 16411I Storage Temperature Range ................. 65C to 150C LT1641-2CS8 16412 Lead Temperature (Soldering, 10 sec).................. 300C LT1641-2IS8 16412I Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: