LT1641 Positive High Voltage Hot Swap Controller FEATURES DESCRIPTIO TM Allows Safe Board Insertion and Removal from a The LT 1641 is an 8-pin Hot Swap controller that allows Live Backplane a board to be safely inserted and removed from a live Controls Supply Voltage from 9V to 80V backplane. Using an external N-channel pass transistor, Programmable Analog Foldback Current Limiting the board supply voltage can be ramped up at a program- High Side Drive for an External N-Channel mable rate. A high side switch driver controls an N-channel Automatic Retry Capability gate for supply voltages ranging from 9V to 80V. User Programmable Supply Voltage Power-Up Rate The chip features a programmable analog foldback cur- Undervoltage Lockout rent limit circuit. If the chip remains in current limit for Overvoltage Protection more than a programmable time, the N-channel pass Available in 8-Lead SO Package transistor turns off and is optionally set to automatically restart after a time-out delay. U APPLICATIO S The PWRGD output indicates when the output voltage, sensed by the FB pin, is within tolerance. The ON pin Hot Board Insertion provides programmable undervoltage lockout. Electronic Circuit Breaker Industrial High Side Switch/Circuit Breaker The LT1641-1/LT1641-2 are recommended for new 24V/48V Industrial/Alarm Systems designs. The LT1641 is available in the 8-lead SO 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 Automatic Restart Application R Q1 S 0.01 IRF530 V IN V OUT 24V D1 C L R1 R5 CMPZ R3 SHORT 49.9k 10 5248B 59k PIN 1% 5% 1% 10nF R7 24k 5% V SENSE GATE CC *SMAT70A ON FB R4 3.57k LT1641 1% R2 3.4k 1% PWRGD PWRGD TIMER GND C2 0.68F GND 1641 TA01 *DIODES, INC. 1641fd 1 U ULT1641 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 3 6 GATE Input Voltage (FB, ON)...............................0.3V to 60V GND 4 5 TIMER Output Voltage (PWRGD) ........................0.3V to 100V S8 PACKAGE Output Voltage (GATE) ............................0.3V to 100V 8-LEAD PLASTIC SO T = 125C, = 110C/W Operating Temperature Range JMAX JA NOT RECOMMENDED FOR NEW DESIGNS LT1641CS8 ............................................. 0C to 70C SEE LT1641-1/LT1641-2 LT1641IS8.......................................... 40C to 85C ORDER PART NUMBER S8 PART MARKING Storage Temperature Range ................. 65C to 150C LT1641CS8 1641 Lead Temperature (Soldering, 10 sec).................. 300C LT1641IS8 1641I Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: