PCI Express 2PCI Express 1220 0.25Ω AUX 1μs Force On Test N MOSFET 38 QFN 36 SSOP PCI Express PC LTC4242 PCI Express LTC 4242 PCI Express 2 N 12 3.3 3.3 12 3.3 LTC4242 CC EN PCI Express FAULT AUXFAULT PGOOD AUXPGOOD LT LTC LTM Hot Swap PCI Express 1
CC... 0.3 7 12 INn... 0.3 20 3 INn... 0.3 10 AUXINn... 0.3 10 ONn, AUXONn, FONn... 0.3 7 ENn... 0.3 7 FAULTn, PGOODn, AUXFAULTn, AUXPGOODn... 0.3 7 12 SENSEn... 0.3 20 12 GATEn... 0.3 25 12 OUTn (Note 3)... 12 GATEn 5 2 GATEn + 0.3 AUX OUTn, 3 SENSEn... 0.3 10 3 GATEn... 0.3 14 3 OUTn (Note 3)... 3 GATEn 5 to 3 GATEn + 0.3 LTC4242C... 0 70 LTC4242I... 40 85 SSOP... 65 150 QFN... 65 125 10 SSOP... 300 T JMAX = 125 C, θ JA = 95 C/W T JMAX = 125 C, θ JA = 34 C/W EXPOSED PAD (PIN 39) IS GND, PCB ELECTRICAL CONNECTION OPTIONAL ORDER PART NUMBER ORDER PART NUMBER UHF PART MARKING* LTC4242CG LTC4242IG Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ LTC4242CUHF LTC4242IUHF 4242 4242 * 2
TA 25ºC CC = AUXINn = 3INn = 3.3 12INn = 12 (Note 2) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Supplies IN Operating oltage CC 12 INn 3 INn AUXINn I DD Input Supply Current AUXONn = 2, ONn = 2 CC 12 INn 3 INn UL Supply Undervoltage Lockout CC Rising 12 INn Rising 3 INn Rising AUXINn Rising Δ LKO(HYST) Supply Undervoltage Lockout Hysteresis CC 12 INn 3 INn AUXINn Current Limit Δ SENSE(CB) Δ SENSE(ACL) Circuit Breaker Trip Sense oltage 12 INn 12 SENSEn 3 INn 3 SENSEn Active Current Limit Sense oltage 12 INn 12 SENSEn 3 INn 3 SENSEn 2.7 10.1 3.0 3.0 2.3 9.48 2.57 2.57 30 90 20 20 45 45 1.6 0.5 0.35 2.45 9.78 2.67 2.67 100 130 35 35 50 50 6.0 14.4 6.0 6.0 4 1 1 2.6 10.08 2.77 2.77 200 170 50 50 75 75 100 100 125 125 m m I CBAUX Circuit Breaking Current for AUX Supply 385 550 715 ma t CB Circuit Breaker Response Time 10 20 40 μs Switch Resistance R AUX Internal Switch Resistance (Note 4) R AUX = ( AUXINn AUXOUTn )/I I = 375mA 0.25 0.4 Ω External Gate Drive I GATE(UP) External N-Channel Gate Pull-Up Current Gate Drive On 12GATEn = 1 3GATEn = 1 I GATE(DN) External N-Channel Gate Pull-Down Current Gate Drive Off 12GATEn = 17, 12OUTn = 12 3GATEn = 8.3, 3OUTn = 3.3 I GATE(FPD) Δ GATE External N-Channel Gate Fast Pull-Down Current External N-Channel Gate Drive 12 GATEn 12 OUTn 3 GATEn 3 OUTn Fast Turn Off 12GATEn = 17, 12OUTn = 12 3GATEn = 8.3, 3OUTn = 3.3 I GATE = 1μA (Note 3) Input Pins PG(TH) Power Good Threshold oltage 12 OUTn Falling 3 OUTn Falling AUXOUTn Falling (Note 5) PG(HYST) Power Good Hysteresis 12 OUTn 3 OUTn AUXOUTn (Note 5) 5 5 0.5 0.5 150 150 4.5 4.5 10.08 2.772 2.772 20 5 5 9 9 1 1 250 250 5.5 5.5 10.38 2.855 2.855 70 20 20 55 55 13 13 2 2 400 400 7.9 7.9 10.68 2.937 2.937 110 30 30 ma ma ma m m m m m m μa μa ma ma ma ma m m m 3
TA 25ºC CC = AUXINn = 3INn = 3.3 12INn = 12 (Note 2) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS ON(TH) ONn, AUXONn Pin Threshold oltage Rising Edge 1.173 1.235 1.297 Δ ON(TH) ONn, AUXONn Pin Hysteresis 30 70 120 m ON(RTH) ONn, AUXONn Pin Reset Threshold oltage Falling Edge 0.5 0.6 0.7 I ON(IN) ONn, AUXONn Pin Input Current ONn = AUXONn = 1.2 ±1 μa EN(TH) ENn Pin Threshold oltage ENn Rising 1.173 1.235 1.297 Δ EN(HYST) ENn Pin Hysteresis 30 70 120 m I EN(UP) ENn Pull-Up Current ENn = 1 5 9 13 μa FON FONn Pin Logic Threshold 0.7 2.6 I SENSE SENSE Pin Input Current 12 SENSEn 3 SENSEn 12SENSEn = 12 3SENSEn = 3.3 40 40 100 100 μa μa I OUT OUT Pin Input Current Gate Drive On 12 OUTn 3 OUTn 12OUTn = 12 3OUTn = 3.3 45 27 90 60 μa μa R OUT(DIS) Output Pins OL I PU OUT Pin Discharge Resistance 12 OUTn 3 OUTn AUXOUTn Output Low oltage FAULTn, AUXFAULTn, PGOODn, AUXPGOODn (Note 5) Pull-Up Current FAULTn, AUXFAULTn, PGOODn, AUXPGOODn (Note 5) Gate Drive Off 12OUTn = 6 3OUTn = 2 AUXOUTn = 2 I PIN = 3mA PIN = 1.5 350 165 375 700 330 750 1400 660 1500 Ω Ω Ω 0.14 0.4 5 9 13 μa Slew Rate SR AUXOUT AUXOUTn Slew Rate 1.25 1.7 /ms Delays t PLH(GATE) Input High (ONn) to GATEs High Prop Delay 7 14 μs t PLH(UL) Input Supply Low (12 INn, 3 INn ) to GATEs 18 Low Prop Delay 36 μs t PLH(PG) Out Low (12 OUTn, 3 OUTn ) to PGOOD High 20 Prop Delay 40 μs t PHL(SENSE) Sense oltage High to GATE Low ΔSENSE = 200m, C GATE = 10nF 0.4 1 μs Note 1 Note 2 GND Note 3 GATE OUT 5 Note 4 QFN AUX FET Note 5 QFN 4
T A 25ºC CC = AUXINn = 3INn = 3.3 12INn = 12 (Note 2) I DD CC CC 12 INn 3 INn 12 INn U 3 INn AUX INn 12 OUTn 3 OUTn AUXOUT n OUT ONn AUXONn ENn L H ONn AUXONn ENn 5
T A 25ºC CC = AUXINn = 3INn = 3.3 12INn = 12 (Note 2) FONn L H CC FONn H L CC R ON R ON AUXINn I GATE 6
T A 25ºC CC = AUXINn = 3INn = 3.3 12INn = 12 (Note 2) I GATE I GATE 7
12 GATE1 /12 GATE2 12 N MOSFET 9μA 12 GATEn 1mA 12 GATEn 12 GATEn 12 OUTn 5.5 12 GATEn 12 OUTn 250mA RC 12 SENSE1 /12 SENSE2 12 12 12 INn 12 SENSEn 12 12 SENSEn 12 INn 12 IN1/ 12 IN2 12 12 INn 9.78 12 3.3 12 OUT1 /12 OUT2 12 12 N MOSFET 10.38 PGOOD1/ PGOOD2 L MOSFET 700Ω 12 OUTn 3 GATE1 /3 GATE2 3.3 N MOSFET 9μA 3 GATEn 1mA 3 GATEn 3 GATEn 3 OUTn 5.5 3 GATEn 3 OUTn 250mA RC 3 SENSE1 /3 SENSE2 3.3 3.3 3 INn 3 SENSEn 3.3 3 SENSEn 3 INn 3 IN1/ 3 IN2 3.3 3 INn 2.67 3.3 12 3 OUT1 /3 OUT2 3.3 3.3 N MOSFET 2.855 PGOOD1/PGOOD2 L MOSFET 375Ω 3 OUTn AUXFAULT1/AUXFAULT2 AUX AUXFAULTn 9μAH 150 AUX L FONn ENn H ON AUXON1/AUXON2 AUX FET 3.5μs 0.6 AUX AUXIN1/AUXIN2 AUX AUXINn 2.67 AUX AUXINn FET AUXOUT1/AUXOUT2 AUX AUXOUTn FET 2.855 AUXPGOOD1/AUXPGOOD2 L FET 750Ω AUXOUTn 8
AUXPGOOD1/AUXPGOOD2 (QFN) AUX AUXOUTn ENn H AUXONn L CC AUXINn ULO 9μA H EN1/EN2/ ENn 1.235 9μA QFN PCB FAULT1/FAULT2 FAULTn 9μAH 12 3.3 FAULTn L FON1/FON2H 12 3.3 AUX ONn AUXONn CC ULO FONn GND ON1/ON2 12 3.3 MOSFET 12 3.3 0.6 PGOOD1/PGOOD2 12 OUTn 3 OUTn ENn H ONn L CC ULO 9μA H CC 2.7 6 CC 2.45 9
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LTC4242 PCI Express 2 2 9μA N MOSFET MOSFET 5.5 AUX FET 1.25/ms ECB ACL IN SENSE ACLECB 2 ACL MOSFET 20μs MOSFET FAULT L MOSFET AUX FET 550mA 20μs AUX FET 1.65A 150AUX FET AUXFAULT LFET OUTN OUT PG PGOOD/AUXPGOOD LTC4242 ULO ON EN ULO CC FON LTC4242 / CC ULO FON LTC4242 2 PCI Express HPC LTC4242 1 PCI Express PCB PCI Express 2 PRSNT1 PRSNT2 2 PRSNT2 HPC 1 HPC HPC LTC4242 3 11
1. PCI Express 12
2. 3. RC PRSNT2 LC D R D ENn L 1ms R D 47k C D t ms CD = DELAY1 ( ) μf = 0. 023 μf 43. 5 33nF C D 0. 765C t D DELAY 2 = s =28. ms 9 PCI Express 12 3.3 N Q1 Q4 3.3 R1 R4 R G1 R G4 13
C G1 C G4 C G1 C G4 R5 R8Q1 Q4 N MOSFET 1. CC / / ULO 2. EN L ON LTC424212 3.3 3.3 AUXON ON 2 ONON H ON L ON H 4 EN L 9μA GATE GATE9μA/ C G C L /C G 9μA C L 1.25/ms 3.3 AUX ULO ECB PGOOD AUXPGOOD QFN L 4. 1. ON/AUXON L / 2. EN H 3. 4. ON L 1mA PGOOD H AUXPGOOD H 5 EN H 14
5. 6. 3.3 3.32 150 C AUXFAULT L 120AUXON L H LTC4242 ECB ACL ECB 20μs 6 ECBFET ACL ECB 2 20μs 7. 3.3 LTC4242 MOSFET MOSFET MOSFET ns MOSFET 15
ULO 38μs CC 20μs /AUX PGOOD/AUXPGOOD H PGOOD/AUXPGOOD L R G /C G ACL ECB 2 ACL 550mA 3 ECB 20μs 12 3.3 3.3 3.3 ACL MOSFET 18μs MOSFET 12 IN 3 IN AUXIN 18μs 3.3 CC 16 8. 3.3AUX 1. 2. EN L 3. 4. ON H 5. ON L ULO AUXON L ULO CC ULO FON H 9 LTC4242 FAULT ON RC 10 LTC4242 ( ) RAUTO CAUTO 1. 235 OL toff 2. 065 + RAUTO 9μA t OFF = 3.3ms 40μs 1.3%
CC LTC4242 CC 1μF CC 3 IN AUXIN 11 9. RC CC ULO LTC4242 3 IN / AUXIN AUXIN 3 IN AUXIN 3 IN 10 CC 7 R S C1 CC 7 11. CC RC GATE 10. 4.5 N MOSFET GATE OUT 5.5 R G C G C G R G R G 10Ω 100Ω FON H EN L LTC4242 ON ECB FAULT/AUXFAULT L CC FON FON H FON H 17
Force ON FON EN H ACL 20μs AUX AUX I CBAUX AUXFAULT AUX FET FON EN L ON AUXON PCB LTC4242 PCB MOSFET PCB 12 MOSFET PCB 12 10A PCB 1 0.5mΩ/ PCB 1DC 1 0.03 PCB 1 1 DC 1A PCB 18 12. 12MOSFETGATE
10μF CC GND CC C1 PCI Express 1. PCI Express 12 5.5A 2000μF 3.3 3.0A 1000μF 3.3 AUX 375mA 150μF 1. R SENSE Δ SENSE(CB)(MIN) R SENSE PCI Express 125 3.33 3.3 AUX 11 1.1A 1% 2. R SENSE (1%) I TRIP(MIN) I TRIP(MAX) 12 8mΩ 5.6A 6.9A 3.3 13mΩ 3.4A 4.3A 2. IGATE( UP ) t 1 CGATE = (2) OUT t 1 I GATE(UP)(MAX) = 13μA t 1 = 10ms a. 12 C GATE = 11nF b. 3.3 C GATE = 39nF 12 3.3 15nF 47nF 10% t 1 3 3. t 1 t 1(MIN) t 1(MAX) I INRUSH 12 13ms 40ms 2.4A 3.3 11ms 34ms 0.4A 3.3 AUX SR 1.7/ms I INRUSH(MAX) = C LOAD SR MAX (3) 385mA I CBAUX(MIN) 30% C LOAD 170μF 3. 12 3.3MOSFET GS = 4.5 25 C Si7336ADP4mΩ 3.3 12 3.3 3A MOSFET 36mW Si7336ADP 50 C/W 50 51.8 Si- 7336ADP 12% RON 4.5mΩ 52 C 3A PCB 50 3.3MOSFET 53m MOSFET MOSFET MOSFET 2 CL OUT PON = 2 t1 (4) 19
P ON t 1 MOSFET θ JA(MAX) 12 MOSFET 4. MOSFET P ON θ JA(MAX) ΔT 12 11W 0.75 C/W 8.3 C 3.3 0.5W 0.6 C/W 0.3 C 2 20μs MOSFET MOSFET LTC4242 MOSFET 150 20
4 12 5 3.3 3.3 21
G 36 SSOP (5.3mm) (Reference LTC DWG # 05-08-1640) NOTE: 1. 2. ( ) 3. * 0.152mm(0.006") ** 0.254mm(0.010") 22
UHF 38 QFN (5mm 7mm) (Reference LTC DWG # 05-08-1701) 1 R 0.30 0.35 45 1 NOTE 6 NOTE: 1. JEDEC M0-220 WHKD 2. 3. 4. 0.20mm 5. 6. 1 23
AMC Advanced Mezzanine Card 2 LTC4210 6 SOT-23 LTC4213 No R TM SENSE 3 LTC4214 0 16 LTC4215 I 2 C 2.9 15 8 ADC LTC4216 0 6 LT 4220 2.7 16 LTC4221 LTC4241 PCI 3.3 No R SENSE 24 1106 PRINTED IN JAPAN LINEAR TECHNOLOGY CORPORATION 2006