DDR Termination Regulator
TJ2997
FIGURE 4. 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 TJ2997 in
applications utilizing DDR-II memory. Figure 3 and Figure 4 show several implementations of
recommended circuits. Figure 3 shows the recommended circuit configuration for DDR-II applications.
The output stage is connected to the 1.8V rail and the AVIN pin can be connected to either a 3.3V or 5V
rail.
FIGURE 5. Recommended DDR-II Termination
If it is not desirable to use the 1.8V rail it is possible to connect the output stage to a 3.3V rail. Care
should be taken to do not exceed the maximum junction temperature as the thermal dissipation
increases with lower VTT output voltages. For this reason it is not recommended to power PVIN off a rail
higher than the nominal 3.3V. The advantage of this configuration is that it has the ability to source and
sink a higher maximum continuous current.
FIGURE 6. DDR-II Termination with higher voltage rails
Apr, 2011 - R1.0.1
10/13
HTC
HTC [ HTC KOREA TAEJIN TECHNOLOGY CO. ]
