LTC1421/LTC1421-2.5 Hot Swap Controller FEATURES DESCRIPTIO TM n Allows Safe Board Insertion and Removal from a The LTC 1421/LTC1421-2.5 are Hot Swap controllers Live Backplane that allow a board to be safely inserted and removed from a n System Reset and Power Good Control Outputs live backplane. Using external N-channel pass transistors, n Programmable Electronic Circuit Breaker the board supply voltages can be ramped up at a program- n User Programmable Supply Voltage Power-Up Rate mable rate. Two high side switch drivers control the N- n High Side Driver for Two External N-Channels channel gates for supply voltages ranging from 3V to 12V. n Controls Supply Voltages from 3V to 12V A programmable electronic circuit breaker protects against n Connection Inputs Detect Board Insertion or Removal shorts. Warning signals indicate that the circuit breaker n Undervoltage Lockout has tripped, a power failure has occurred or that the switch n Power-On Reset Input drivers are turned off. The reset output can be used to generate a system reset when the power cycles or a fault U occurs. The two connect inputs can be used with stag- APPLICATIO S gered connector pins to indicate board insertion or re- n Hot Board Insertion moval. The power-on reset input can be used to cycle the n Electronic Circuit Breaker board power or clear the circuit breaker. The trip point of the ground sense comparator is set at 0.1V for LTC1421 and 2.5V for LTC1421-2.5. The LTC1421/LTC1421-2.5 are available in 24-pin SO and , LTC and LT are registered trademarks of Linear Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation. SSOP packages. TYPICAL APPLICATIO Q3 1/2 Si4936DY V EE 12V C3 R4 1A C LOAD 0.47m F + 20k V EE R2 Q2 5% 0.025W 1/2 Si4936DY V DD 1 2 12V V DD + 1A 3 4 C R1 Q1 LOAD 0.005W MTB50N06E V CC 1 2 5V V CC 10k + R6 5A 3 4 C 20k LOAD C2 23 22 21 20 19 18 17 16 D1 1% 0.1m F V SETLO GATELO V V SETHI GATEHI V R5 CCLO OUTLO CCHI OUTHI 10 16k RAMP R3 5% 2 9 1k CON2 CPON 24 14 AUXV COMP CC 13 R7 C1 + 1m F COMP 1m F 7.15k LTC1421 8 REF 1% 4 11 FAULT FAULT FB m P 15 COMPOUT I/O 3 6 POR POR PWRGD I/O 1 7 CON1 RESET RESET GND DISABLE 12 5 1 GND BEA V CC 13 BEB 12 DATA BUS GND DATA 1421 TA01 QS3384 BUS QuickSwitch IS A REGISTERED TRADEMARK QuickSwitch OF QUALITY SEMICONDUCTOR CORPORATION. BACKPLANE PC BOARD 1 STAGGERED CONNECTOR U ULTC1421/LTC1421-2.5 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART Supply Voltage (V , V , AUXV ) .............. 13.2V TOP VIEW CCLO CCHI CC NUMBER Input Voltage (Analog Pins) ..... 0.3V to (V + 0.3V) 1 AUXV CCHI CON1 24 CC Input Voltage (Digital Pins)................... 0.3V to 13.2V 2 V CON2 23 CCLO LTC1421CG 3 SETLO Output Voltage (Digital Pins) .. 0.3V to (V + 0.3V) POR 22 CCLO LTC1421CSW 4 GATELO FAULT 21 Output Voltage (CPON) ......... 13.2V to (V + 0.3V) CCLO LTC1421CG-2.5 5 V DISABLE 20 OUTLO Output Voltage (V , V ) ........... 0.3V to 13.2V OUTLO OUTHI LTC1421CSW-2.5 6 V PWRGD 19 CCHI Output Voltage (GATELO, GATEHI) ........... 0.3V to 20V LTC1421IG 7 SETHI RESET 18 Operating Temperature Range LTC1421ISW 8 GATEHI REF 17 LTC1421C ............................................... 0 C to 70 C LTC1421IG-2.5 9 V CPON 16 OUTHI LTC1421I........................................... 40 C to 85 C LTC1421ISW-2.5 10 COMPOUT RAMP 15 Storage Temperature Range ................ 65 C to 150 C 11 COMP FB 14 Lead Temperature (Soldering, 10 sec)................. 300 C + 12 COMP GND 13 G PACKAGE SW PACKAGE 24-LEAD PLASTIC SSOP 24-LEAD PLASTIC SO T = 125 C, q = 100 C/W (G) JMAX JA T = 125 C, q = 85 C/W (SW) JMAX JA Consult factory for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. V = 12V, V = 5V unless otherwise noted (Note 2). A CCHI CCLO SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS DC Characteristics I V Supply Current CON1 = CON2 = GND, POR = V l 1.5 3 mA CCLO CCLO CCLO I V Supply Current CON1 = CON2 = GND, POR = V l 0.6 1 mA CCHI CCHI CCLO V Undervoltage Lockout V and V 2.28 2.45 2.60 V LKO CCLO CCHI V Undervoltage Lockout Hysteresis V and V 100 mV LKH CCLO CCHI V Reference Output Voltage No Load l 1.220 1.232 1.244 V REF D V Reference Line Regulation 3V V 12V, No Load l 48 mV LNR CCLO D V Reference Load Regulation I = 0mA to 5mA, Sourcing Only l 13 mV LDR O I Reference Short-Circuit Current V = 0V 45 mA RSC REF V Comparator Offset Voltage 0V V (V - 1.3V) l 10 mV COF CM CCLO V Comparator Power Supply Rejection 0V V (V - 1.3V), 3V V 12V l 1 mV/V CPSR CM CCLO CCLO V Comparator Hysteresis 0V V (V - 1.3V) 7 mV CHST CM CCLO V Reset Voltage Threshold (V ) FB = V l 2.80 2.90 3.00 V RST OUTLO OUTLO FB = Floating l 4.50 4.65 4.75 V FB = GND l 5.75 5.88 6.01 V V Reset Threshold Hysteresis (V ) FB = V 7mV RHST OUTLO OUTLO FB = Floating 12 mV FB = GND 15 mV R FB Pin Input Resistance 0V V V 95 kW FB FB CCLO V Circuit Breaker Trip Voltage V = (V V ) or V = (V V ) l 40 50 60 mV CB CB CCLO SETLO CB CCHI SETHI V Output Voltage for Re-Power-Up LTC1421 (Note 3) 0.1 V TRIP LTC1421-2.5 (Note 4) 2.5 V 2 U U WWW WU