1.6 V to 16.5 V Hot Swap Controller with Soft Start Data Sheet ADM1170 FEATURES GENERAL DESCRIPTION Controls supply rails from 1.6 V to 16.5 V The ADM1170 is a hot swap controller that safely enables a Supply voltage range from 2.7 V to 16.5 V printed circuit board to be removed and inserted to a live Allows protected board removal and insertion to a live backplane. This is achieved using an external N-channel power backplane MOSFET with a current control loop that monitors the load External sense resistor provides adjustable analog current current through a sense resistor. An internal charge pump is limit with circuit breaker used to enhance the gate of the N-channel FET. When an Soft start controls inrush current profile overcurrent condition is detected, the gate voltage of the FET is Peak fault current limited with fast response reduced to limit the current flowing through the sense resistor. Charge pumped gate drive for external N-FET switch Automatic retry or latch-off during current fault The ADM1170 operates with a supply voltage ranging from Undervoltage lockout 2.7 V to 16.5 V. By using independent SENSE pins from VCC, 8-lead, TSOT package the ADM1170 allows for the hot swap of supplies ranging down to 1.6 V. During an overcurrent condition, the TIMER pin APPLICATIONS capacitor determines the amount of time the FET remains at a current limiting mode of operation until it is shut down. The Hot swap board insertion: line cards, raid systems CLR ON (ON- ) pin is the enable input for the device and can be Industrial high-side switches/circuit breakers used to monitor the input supply voltage. The ADM1170 also Electronic circuit breakers features soft start to provide the user with a capacitor program- mable ramping reference to the internal current sense comparator. This provides a linearly increasing current limit at startup at a rate set by CSS. This helps to reduce and limit large inrush currents. This device is available in two options: the ADM1170-1 with automatic retry for overcurrent fault and the ADM1170-2 with latch-off for an overcurrent fault. Toggling the ON (ON-CLR) pin resets a latched fault. The ADM1170 is packaged in an 8-lead TSOT. FUNCTIONAL BLOCK DIAGRAM R SENSE Q LONG 1 V = 1.8V V = 1.8V IN OUT C LOAD SENSE+ SENSE V = 3.3VAUX LONG IN V CC GATE ADM1170-1 R ON1 SHORT ON SS R ON2 C SS TIMER GND C TIMER GND LONG GND Figure 1. Rev. A Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20062013 Analog Devices, Inc. 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Technical Support www.analog.com 05124-001ADM1170 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 UVLO ........................................................................................... 11 Applications ....................................................................................... 1 ON (ON-CLR) Pin ..................................................................... 11 General Description ......................................................................... 1 GATE ........................................................................................... 11 Functional Block Diagram .............................................................. 1 Current Limit Function ............................................................. 11 Revision History ............................................................................... 2 Calculating the Current Limit .................................................. 11 Specifications ..................................................................................... 3 Circuit Breaker Function ........................................................... 11 Absolute Maximum Ratings ............................................................ 4 Timer Function ........................................................................... 12 Thermal Characteristics .............................................................. 4 Power-Up Timing Cycle ............................................................ 12 ESD Caution .................................................................................. 4 Circuit Breaker Timing Cycle ................................................... 12 Pin Configurations and Function Descriptions ........................... 5 Automatic Retry or Latched Off ............................................... 13 Typical Performance Characteristics ............................................. 6 Soft Start ...................................................................................... 13 Theory of Operation ...................................................................... 11 Outline Dimensions ....................................................................... 14 Overview ...................................................................................... 11 Ordering Guide .......................................................................... 14 REVISION HISTORY 1/ 13Rev. 0 to Rev. A Changes to Figure 36 ...................................................................... 13 Changes to Ordering Guide .......................................................... 14 7/06Revision 0: Initial Version Rev. A Page 2 of 16