Datasheet

4.8
JP3
Current Mode Control
4.9
JP4
DDR Mode
4.10
JP4
DDR2 Mode
4.11
JP4
DDR3 or Adjustable Output Voltage
4.12 Self-Driven LDO Supply Voltage
4.13 External LDO Supply Voltage
Configuration www.ti.com
The TPS51116EVM can be configured to operate in a more conventional current mode control. In this
mode, the transconductance amplifier’s output is connected to the compensation network.
To program the EVM for current mode control, set JP3 into the lower position.
The TPS51116EVM can be configured to operate in DDR mode, setting the switching regulator output
voltage (V
VDDQ
) to 2.5 V and the LDO termination voltage (V
VTT
) to 1.25 V.
To program the EVM for DDR mode, place the JP4 jumper in the center vertical position.
The TPS51116EVM comes preconfigured in DDR2 mode, setting the switching regulator output voltage
(V
VDDQ
) to 1.8 V and the LDO termination voltage (V
VTT
) to 0.9 V.
To program the EVM for DDR2 mode, place the JP4 jumper in the right horizontal position.
The TPS51116EVM can be configured to operate in DDR3 or adjustable output mode, allowing the user to
set V
VDDQ
between 1.5 V and 3.0 V by selecting the R10 and R11 voltage divider and using the internal
750-mV reference. The V
VTT
output voltage tracks at of this adjustable voltage. The default values for R10
and R11 provide DDR3 voltage levels. These set the switching regulator voltage (V
VDDQ
) to 1.5 V and the
LDO termination voltage (V
VTT
) to 0.75 V.
To program the EVM for adjustable output voltage mode, place the JP4 jumper in the left horizontal
position.
Table 3. Adjustable Output Voltage Resistor Values
(1)
V
VDDQ
(V) V
VTT
(V) R10 (k Ω ) R11 (k Ω )
3.0 1.50 14.3 4.75
2.7 1.35 12.4 4.75
2.0 1.00 8.06 4.75
(1)
For adjustable output voltage mode, place the JP4 jumper in the left horizontal position.
The TPS51116EVM comes preconfigured in self-driven LDO supply voltage mode. In this mode, the LDO
is supplied directly from the V
VDDQ
switching regulator’s output, eliminating the need for an external supply
voltage.
To program the EVM for self-driven LDO supply voltage, place a short in the R1 position.
The TPS51116EVM can be configured in an external LDO supply voltage mode. In this mode the LDO is
supplied by an external voltage source not produced by the TPS51116, allowing the user to select another
power rail to provide power to the VLDOIN by removing the 0- Ω resistor from the R1 position and applying
an external supply to the LDOIN_EX pin (J1) on the EVM board.
Using the TPS51116EVM8 SLUU202A – SEPTEMBER 2004 – Revised November 2008
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