LP2996M National Semiconductor, LP2996M Datasheet - Page 13

• Manufacturer Part Number: LP2996M
• Description: IC, REG DDR TERMINATION, SMD, SO-8
• Manufacturer: National Semiconductor

Specifications of LP2996M

• Primary Input Voltage: 2.5V
• Output Voltage: 1.35V
• No. Of Pins: 8
• Output Current: 1.5A
• Voltage Regulator Case Style: SOIC
• Operating Temperature Range: 0°C To +125°C
• Svhc: No SVHC (15-Dec-2010)
• Output Voltage Fixed: 1.35V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

LEVEL SHIFTING
If standards other than SSTL-2 are required, such as SSTL-3,
it may be necessary to use a different scaling factor than 0.5
times V
are available to scale the output to any voltage required. One
method is to level shift the output by using feedback resistors
Conversely, the R2 resistor can be placed between V
and V
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
DDQ
DDQ
to shift the V
for regulating the output voltage. Several options
DDQ
to the 1.5V rail. This will produce a V
TT
output lower than the internal refer-
FIGURE 11. Decreasing VTT by Level Shifting
FIGURE 10. Increasing VTT by Level Shifting
FIGURE 12. HSTL Application
TT
SENSE
and
13
from V
10 and 11. Figure 10 shows how to use two resistors to level
shift V
calculate the exact voltage at V
be used.
V
sistors. AVIN and PVIN should be connected to a 2.5V rail for
optimal performance.
REF
voltage of approximately 0.75V for the termination re-
TT
TT
to the V
above the internal reference voltage of VDDQ/2. To
SENSE
V
V
TT
TT
= VDDQ/2 ( 1 + R1/R2)
= VDDQ/2 (1 - R1/R2)
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pin. This has been illustrated in Figures
20057515
20057517
TT
the following equation can
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