LTC4240IGN#TR Linear Technology, LTC4240IGN#TR Datasheet
LTC4240IGN#TR
Specifications of LTC4240IGN#TR
Available stocks
Related parts for LTC4240IGN#TR
LTC4240IGN#TR Summary of contents
Page 1
... APPLICATIO S Hot Board Insertion into CompactPCI Bus Electronic Circuit Breaker , LTC and LT are registered trademarks of Linear Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation. QuickSwitch is a registered trademark of Quality Semiconductor Corp. CompactPCI is a trademark of the PCI Industrial Computer Manufacturers Group. ...
Page 2
LTC4240 ABSOLUTE AXI U RATI GS (Notes 1, 2) Supply Voltages 5V IN .................................................................... 12V IN ................................................................. V EEIN ................................................................... Input Voltages PRSNT1#, PRSNT2#, SCL, RESETIN, OFF/ON .................................................. –0.3V to 12V ...
Page 3
ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER V 12V Switch Voltage Drop 12V V V Switch Voltage Drop VEE EE I Current Foldback CL I Current Fault Threshold TH T Thermal Shutdown Temperature TS V Power ...
Page 4
LTC4240 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER t Stop Condition Setup Time SUSTP t Data Hold Time HDDAT t Data Setup Time SUDAT t Clock Low Period LOW t Clock High Period HIGH t Clock/Data ...
Page 5
W U TYPICAL PERFOR A CE CHARACTERISTICS V Supply Current EEIN vs Temperature –0.8 OFF/ –0.9 –1.0 –1.1 –1.2 –50 – 100 TEMPERATURE ( C) 4240 G07 12V Output Current 1.6 12V = 12V ...
Page 6
LTC4240 W U TYPICAL PERFOR A CE CHARACTERISTICS 3V Input Current SENSE vs Temperature 3.3V SENSE –50 – 100 TEMPERATURE ( C) 4240 G16 Timer Pin Turn-On Current vs ...
Page 7
W U TYPICAL PERFOR A CE CHARACTERISTICS V UVLO Threshold Voltage EEIN vs Temperature –7.6 –8.0 –8.4 –8.8 –9.2 –9.6 –10.0 – 100 –25 TEMPERATURE ( C) 4240 G25 3V Foldback Current Limit Voltage vs Temperature ...
Page 8
LTC4240 CTIO S PRSNT1# (Pin 1): PCI Present Detect Input 1. PRSNT1# and PRSNT2# are readable over the I and PRSNT2# indicate the maximum power used by the card. Do not float. PRSNT2# (Pin 2): ...
Page 9
CTIO S node. An external 1k resistor between the transistor’s base and 3V is needed. IN PRECHARGE (Pin 18): Precharge Monitor Input. An inter- nal error amplifier servos the DRIVE pin voltage to keep the ...
Page 10
LTC4240 W BLOCK DIAGRA SENSE OUT 70mV, +– + TIMER LO 165mV, A1 TIMER HI +– – + CP1 55mV +– – 4.3V UVL OFF/ON 28 FAULT 7 Q13 PWRGD 8 Q12 ...
Page 11
U U APPLICATIO S I FOR ATIO The LTC4240 is a Hot Swap controller that allows a board to be safely inserted and removed from a CompactPCI bus slot. The LTC4240 has built-in 2-wire I interface hardware to allow software ...
Page 12
LTC4240 U U APPLICATIO S I FOR ATIO used to turn off/on the power switches, turn on the status LED (alerting the user that its safe to remove the plug-in board), and assert the LOCAL_PCI_RST# signal. The I bus is ...
Page 13
U U APPLICATIO S I FOR ATIO START and STOP Commands The START command is defined as a high to low transition of the SDA line while the SCL line is high asynchro- nous event issued by ...
Page 14
LTC4240 U U APPLICATIO S I FOR ATIO ADDRESS BYTE SCL START SDA 0 1 ADDR 4 ADDR 3 ADDR 2 Table 2. Command Byte Definitions HIGH C7 Don’t care C6 Don’t care C5 Ignore V ...
Page 15
U U APPLICATIO S I FOR ATIO Table 3 shows the definition for each data bit. PWRGD, FAULT, RESETIN, and RESETOUT external pins can be monitored. PRSNT1# and PRSNT2# are PCI signals that provide information on the power requirements of ...
Page 16
LTC4240 U U APPLICATIO S I FOR ATIO stage in the hot plug sequence, indicating that the LTC4240 is in reset mode with all power switches off (BD_SEL# is still pulled high to long 5V). The 12V and –12V supplies ...
Page 17
U U APPLICATIO S I FOR ATIO Note that capacitor C1 performs dual functions. In addi- tion to controlling the ramp up rates of the 5V and 3.3V outputs, it also compensates the current limit loop. Current limit faults are ...
Page 18
LTC4240 U U APPLICATIO S I FOR ATIO Timer During a power-up sequence, an 11.5 A current source is connected to the TIMER pin (Pin 5) and charges up the external TIMER pin capacitor. Current limit faults are ignored until ...
Page 19
U U APPLICATIO S I FOR ATIO Once the TIMER voltage has reached 5.5V, all of the supplies will be latched off if any supply enters current limit for at least 35 s. The 35 s delay prevents quick current ...
Page 20
LTC4240 U U APPLICATIO S I FOR ATIO sense resistor drops to 0.0049 and the largest value of threshold voltage increases to 60mV. This results in a trip current of 12.2A LOAD(MAX) SENSE ...
Page 21
APPLICATIO S I FOR ATIO Transient Power Dissipation There are certain transient events that can significantly increase the power dissipated by the external FET. If the LTC4240 5V supply ( 10%) powers up into a ...
Page 22
LTC4240 U U APPLICATIO S I FOR ATIO Table 6. R1 and R2 Resistor Values vs Precharge Voltages V R11A R11B V PRECHARGE PRECHARGE 1.5V 18 9.09 0.9V 1.4V 18 7.15 0.8V 1.3V 18 5.36 0.7V 1.2V 18 3.65 0.6V ...
Page 23
U U APPLICATIO S I FOR ATIO than 2 A, then a 50K resistor can be connected directly from the 1V bias voltage to the I/O line. However, many ICs connected to the I/O lines can have leakage currents up ...
Page 24
LTC4240 U U APPLICATIO S I FOR ATIO The assumption by the CompactPCI specification is that there is a diode to 3.3V on the circuit that is driving the BD_SEL# pin. The 1.2k resistor pull card ...
Page 25
U U APPLICATIO S I FOR ATIO Disallowing bulk capacitors on the input power pins mitigates the inrush current during hot plug. However, it also tends to create a resonant circuit formed by the inductance of the backplane power supply ...
Page 26
LTC4240 U U APPLICATIO S I FOR ATIO Note (see front page schematic) that the 12V and –12V show 0.01 F snubber capacitors. This is consistent with the CPCI specification since we also recommend a 10 snubber resistor. The 12V ...
Page 27
... Vishay-Dale Vishay-Siliconix Diodes, Inc. Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights PART NUMBER ...
Page 28
... Eliminates ORing Diodes, Identifies and Localizes Faults www.linear.com .386 – .393* .033 (9.804 – 9.982) (0.838 1615 REF .150 – .157** (3.810 – 3.988 .004 – .009 (0.102 – 0.249) .0250 (0.635) BSC GN28 (SSOP) 0502 LT/TP 0403 2K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2003 4240f ...