NE57810S Philipss, NE57810S Datasheet - Page 10

• Manufacturer Part Number: NE57810S
• Description: Advanced DDR memory termination power with external reference in
• Manufacturer: Philipss

from the outputs emerging from main system power supply. This can
Philips Semiconductors
Externally programmed V
The NE57810 allows use of an external reference voltage to set its
V
where the V
voltage and current to be drawn from a power supply bus that is not
the DDR RAM supply voltage. This may have some advantages
when you are attempting to better match the power being drawn
be seen in Figure 13.
The internal reference voltage is set by two matched 100 k
resistors connected in a resistor divider between the V
pins of the NE57810.
2003 Sep 12
TT
Advanced DDR memory termination power
with external reference in
output voltage. This pin (ExtRefIn pin 4) is used for applications
TT
voltage is not V
EXTERNAL REFERENCE IN
DD
+V
GND
divided by 2. This allows V
DD
TT
output voltage
C
IN
Figure 13. Externally programmed V
DD
and V
V
ExtRefIn
DD
TT
SS
NE57810
V
SS
10
Setting the value of V
an external resistor divider whose resistor values are less than 5 k
each or by connecting the output of an operational amplifier that is
outputting the reference voltage. If the external resistor divider is
used, place a 0.01 F ceramic bypass capacitor between the
ExtRefIn pin (pin 4) and the V
new reference voltage when the external resistor divider is used will
be about 0.5 percent PLUS the sum of the tolerances of the
resistors used in the divider.
Please note that when the NE57810 is operating in this fashion, the
power dissipation of the part may increase.
RefOut
V
TT
TT
.
C
(LF)
ref
OUT
V
REF
or V
TT
SS
can be done in two ways: by placing
pin (pin 3). The accuracy of the
C
(HF)
OUT
SL01679
+V
GND
TT
NE57810
Product data