LTC1645 Dual-Channel Hot Swap Controller/Power Sequencer FEATURES DESCRIPTIO TM n The LTC 1645 is a 2-channel Hot Swap controller that Allows Safe Board Insertion and Removal from a allows a board to be safely inserted and removed from a Live Backplane n live backplane. Using external N-channel pass transistors, Programmable Power Supply Sequencing n the supply voltages can be ramped at a programmable Programmable Electronic Circuit Breaker n rate. Two high side switch drivers control the N-channel User-Programmable Supply Voltage Power-Up and gates for supply voltages ranging from 1.2V to 12V. The Power-Down Rate n two channels can be set to ramp up and down separately, High Side Drivers for External N-Channel FETs n or they can be programmed to rise and fall simultaneously, Controls Supply Voltages from 1.2V to 12V n ensuring power supply tracking at the two outputs. Ensures Proper Power-Up Behavior n Undervoltage Lockout Programmable electronic circuit breakers protect against n Glitch Filter Protects Against Spurious RESET Signals shorts at either output. The RESET output can be used to n 8- and 14-Pin SO Packages generate a system reset when a supply voltage falls below U a user-programmed voltage. An additional spare com- APPLICATIO S parator is available for monitoring a second supply voltage. n Hot Board Insertion n The LTC1645 is available in the 8- and 14-pin SO packages. Power Supply Sequencing n , LTC and LT are registered trademarks of Linear Technology Corporation. Electronic Circuit Breaker Hot Swap is a trademark of Linear Technology Corporation. TYPICAL APPLICATIO 5V and 3.3V Hot Swap 5V and 3.3V Hot Swap Waveforms V 0.005* IRF7413 OUT2 3.3V V IN2 + 5A C LOAD2 ON 5V/DIV V 0.005* IRF7413 OUT1 5V V IN1 + 5A C 10 LOAD1 GATEn 10 10V/DIV 0.01F 0.01F 25V 25V V OUT2 5V/DIV SENSE1 GATE1 V SENSE2 GATE2 CC2 V CC1 V OUT1 LTC1645 5V/DIV (8-LEAD) ON ON 10k GND 1645 TA01 GND *LRF1206-01-R005-J (IRC) BACKPLANE PLUG-IN CARD 1645fa 1 CONNECTOR 2 CONNECTOR 1 U ULTC1645 ABSOLUTE AXI U RATI GS (Note 1) Supply Voltage (V , V ) ................................. 13.2V Output Current CC1 CC2 Input Voltage GATE1, GATE2............................................... 20mA + FB, ON, COMP ..................... 0.3V to (V + 0.3V) Operating Temperature Range CC1 TIMER ................................................. 0.3V to 2.5V LTC1645C ............................................... 0 C to 70 C SENSE1 ..................... (V 0.7V) to (V + 0.3V) LTC1645I............................................ 40 C to 85 C CC1 CC1 SENSE2 ...................... (V 0.7V) to (V + 0.3V) Storage Temperature Range ................. 65 C to 150 C CC1 CC2 Output Voltage Lead Temperature (Soldering, 10 sec).................. 300 C RESET, COMPOUT, FAULT .....................0.3V to 16V GATE1, GATE2................. Internally Limited (Note 3) UUW PACKAGE/ORDER I FOR ATIO ORDER PART ORDER PART TOP VIEW NUMBER NUMBER TOP VIEW V 1 14 V CC2 CC1 SENSE2 2 13 SENSE1 V 1 8 V CC2 CC1 LTC1645CS8 LTC1645CS GATE2 3 12 GATE1 SENSE2 2 7 SENSE1 LTC1645IS8 LTC1645IS FAULT 4 11 TIMER GATE2 3 6 GATE1 RESET 5 10 ON GND ON 4 5 FB 6 9 COMPOUT S8 PART MARKING S8 PACKAGE + GND 7 8 COMP 8-LEAD PLASTIC SO T = 125 C, q = 150 C/ W 1645 S PACKAGE JMAX JA 14-LEAD PLASTIC SO 1645I T = 125 C, q = 110 C/ W JMAX JA Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. A 2.375V V 12V, 1.2V V 12V unless otherwise noted (Note 2). CC1 CC2 SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS DC Characteristics I V Supply Current ON = V = 5V, V = 3.3V l 1.1 2.0 mA CC1 CC1 CC1 CC2 I V Supply Current ON = V = 5V, V = 3.3V l 0.28 0.4 mA CC2 CC2 CC1 CC2 V V Undervoltage Lockout High to Low l 2.16 2.23 2.3 V LKO1 CC1 V V Undervoltage Lockout High to Low l 1.06 1.12 1.18 V LKO2 CC2 V V Undervoltage Lockout Hysteresis 25 mV LKHn CCn V FB Pin Voltage Threshold High to Low l 1.226 1.238 1.250 V FB D V FB Pin Threshold Line Regulation High to Low, V = 2.375V to 12V l 14 mV FB CC1 V FB Pin Voltage Threshold Hysteresis 5 mV FBHST + V COMP Pin Voltage Threshold High to Low l 1.226 1.238 1.250 V COMP + D V COMP Pin Threshold Line Regulation High to Low, V = 2.375V to 12V l 14 mV COMP CC1 + V COMP Pin Voltage Threshold Hysteresis 5 mV COMPHST 1645fa 2 U WWW