 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LTC4235 Datasheet(PDF) 11 Page - Linear Technology |
|
||||||||||||||||||||||||||||||
LTC4235 Datasheet(HTML) 11 Page - Linear Technology |
|
|
11 / 22 page  LTC4235 11 4235f For more information www.linear.com/LTC4235 High availability systems often employ parallel-connected powersuppliesorbatteryfeedstoachieveredundancyand enhance system reliability. Power ORing diodes are com- monlyusedtoconnectthesesuppliesatthepointofloadat the expense of power loss due to significant diode forward voltage drop. The LTC4235 minimizes this power loss by using external N-channel MOSFETs as the pass elements, allowing for a low voltage drop from the supply to the load when the MOSFETs are turned on. When an input source voltage drops below the output common supply voltage, the appropriate MOSFET is turned off, thereby matching the function and performance of an ideal diode. By adding a current sense resistor and a Hot Swap MOSFET after the parallel-connected ideal diode MOSFETs, the LTC4235 enhances the ideal diode performance with inrush current limiting and overcurrent protection (see Figure 1). This allows the board to be safely inserted and removed from a live backplane without damaging the connector. Internal VCC Supply The LTC4235 operates with an input supply from 9V to 14V. The power supply to the device is internally regulated at 5V by a low dropout regulator (LDO) with an output at the INTVCC pin. An internal diode-OR circuit selects the applicaTions inForMaTion highest of the supplies at the IN and OUT pins to power the devicethroughtheLDO.Thediode-ORschemepermitsthe device’s power to be kept alive by the OUT voltage when the IN supplies have collapsed or shut off. AnundervoltagelockoutcircuitpreventsalloftheMOSFETs from turning on until the INTVCC voltage exceeds 2.2V. A 0.1µF capacitor is recommended between the INTVCC and GND pins, close to the device for bypassing. No external supply should be connected at the INTVCC pin so as not to affect the LDO’s operation. A small external load of less than 500µA can be connected at the INTVCC pin. Turn-On Sequence The board power supply at the OUT pin is controlled with external N-channel MOSFETs (MD1, MD2 and MH) in Figure 1. The ideal diode MOSFETs connected in parallel on the supply side function as a diode-OR, while MH on the load side acts as a Hot Swap MOSFET controlling the power supplied to the output load. The sense resistor RS monitors the load current for overcurrent detection. The HGATE capacitor CHG controls the gate slew rate to limit the inrush current. Resistor RHG with CHG compensates the current control loop, while RHpreventshighfrequency oscillations in the Hot Swap MOSFET. Figure 1. Card Resident Diode-OR with Hot Swap Application BACKPLANE CONNECTOR VIN1 12V VIN2 12V CARD CONNECTOR CPO1 GND ON FAULT PWRGD IMON ADC CL 680µF 12V 7A R1 2k INTVCC Z2 SMAJ15A D2OFF IN1 DGATE1 DGATE2 LTC4235 4235 F01 MD2 SiR158DP MH SiR158DP RS 0.003 HGATE OUT SENSE+ SENSE– CPO2 C3 0.1µF C4 0.1µF IN2 + R2 13.7k R3 100k R4 100k RH 10 RHG 1k CHG 10nF REG C2 0.1µF C1 0.1µF MD1 SiR158DP EN CFT 0.1µF C5 0.1µF Z1 SMAJ15A FTMR |
Similar Part No. - LTC4235 |
|
Similar Description - LTC4235 |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
