LP2996 National Semiconductor, LP2996 Datasheet
LP2996
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LP2996 Summary of contents
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... V SENSE output as a reference for the chipset and DIMMs. An additional feature found on the LP2996 is an active low shutdown (SD) pin that provides Suspend To RAM (STR) functionality. When SD is pulled low the V state providing a high impedance output, but, V active ...
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... EP Ordering Information Order Number Package Type LP2996M LP2996MX LP2996MR PSOP-8 LP2996MRX PSOP-8 LP2996LQ LP2996LQX www.national.com 20057502 20057504 Name GND Ground SD Shutdown VSENSE Feedback pin for regulating V VREF Buffered internal reference voltage of V VDDQ Input for internal reference equal to V AVIN ...
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... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. AVIN to GND PVIN to GND VDDQ (Note 2) Storage Temp. Range Junction Temperature SO-8 Thermal Resistance (θ PSOP-8 Thermal Resistance (θ LLP-16 Thermal Resistance (θ ...
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Note 1: Absolute maximum ratings indicate limits beyond which damage to the device may occur. Operating range indicates conditions for which the device is intended to be functional, but does not guarantee specific performance limits. For guaranteed specifications and test ...
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Typical Performance Characteristics and REF DDQ 20057520 20057522 20057524 20057521 REF REF 20057523 OUT 20057525 ...
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DDQ Temperature IN Maximum Sourcing Current 2.5V, PV DDQ www.national.com 20057526 20057528 IN = 2.5V) IN 20057532 Temperature IN 20057527 Maximum Sourcing Current ...
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Maximum Sinking Current 2.5V) DDQ Maximum Sinking Current 1.8V) DDQ Block Diagram Maximum Sourcing Current DDQ 20057534 Maximum Sourcing Current DDQ 20057536 7 IN ...
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... FIGURE 1. SSTL-Termination Scheme Pin Descriptions AVIN AND PVIN AVIN and PVIN are the input supply pins for the LP2996. AVIN is used to supply all the internal control circuitry. PVIN, how- ever, is used exclusively to provide the rail voltage for the output stage used to create VTT. These pins have the capa- bility to work off separate supplies depending on the applica- tion ...
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... Despite the fact that the LP2996 is designed to handle large transient output currents it is not capable of handling these for long durations, under all conditions. The reason for this is the standard packages are not able to thermally dissi- pate the heat as a result of the internal power loss ...
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... V cannot source and sink current simultaneously 20057508 P VTT The power dissipation of the LP2996 can also be calculated during the shutdown state. During this condition the output V will tri-state, therefore that term in the power equation will can also disappear as it cannot sink or source any current (leakage is negligible) ...
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... The third option for SSTL-2 applications in the situation that a 1.8V rail is not available and it is not desirable to use 2.5V connect the LP2996 power rail to 3.3V. In this situation AVIN will be limited to operation on the 3. rail as PVIN can never exceed AVIN. This configuration has the ability to ...
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... FIGURE 7. SSTL-2 Implementation with higher voltage rails DDR-II APPLICATIONS With the separate VDDQ pin and an internal resistor divider it is possible to use the LP2996 in applications utilizing DDR- II memory. Figure 6 and Figure 7 show several implementa- tions of recommended circuits with output curves displayed in the Typical Performance Characteristics. ...
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... DDQ TT ence voltage of VDDQ/2. The equations relating VTT and the resistors can be seen below: HSTL APPLICATIONS The LP2996 can be easily adapted for HSTL applications by connecting V to the 1.5V rail. This will produce a V DDQ from V to the and 11 ...
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... However, this increase in bus lines has the effect of increasing the current levels re- quired for termination. The recommended approach in termi- nating multiple channels is to use a dedicated LP2996 for each channel. This simplifies layout and reduces the internal power dissipation for each regulator. Separate V ...
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PCB Layout Considerations 1. The input capacitor for the power rail should be placed as close as possible to the PVIN pin should be connected to the V SENSE at the point where regulation is required. For motherboard ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 8-Lead Small Outline Package (M8) NS Package Number M08A 16 ...
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LLP Package (LD) NS Package Number LQA16A 8-Lead PSOP Package (PSOP-8) NS Package Number MRA08A 17 www.national.com ...
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