Datasheet
Table Of Contents
- FEATURES
- APPLICATIONS
- DESCRIPTION
- ABSOLUTE MAXIMUM RATINGS
- THERMAL INFORMATION
- RECOMMENDED OPERATING CONDITIONS
- ELECTRICAL CHARACTERISTICS
- DEVICE INFORMATION
- TYPICAL CHARACTERISTICS
- APPLICATION INFORMATION
- VDDQ Switch Mode Power Supply Control
- VREF and REFIN, VDDQ Output Voltage
- Soft-Start and Powergood
- Power State Control
- MODE Pin Configuration
- Discharge Control
- D-CAP™ Mode
- D-CAP2™ Mode Operation
- Light-Load Operation
- VTT and VTTREF
- VDDQ Overvoltage and Undervoltage Protection
- VDDQ Out-of-Bound Operation
- VDDQ Overcurrent Protection
- VTT Overcurrent Protection
- V5IN Undervoltage Lockout Protection
- Thermal Shutdown
- External Components Selection
- Layout Considerations
TPS51916
SLUSAE1D –DECEMBER 2010–REVISED JUNE 2012
www.ti.com
Power State Control
The TPS51916 has two input pins, S3 and S5, to provide simple control scheme of power state. All of VDDQ,
VTTREF and VTT are turned on at S0 state (S3=S5=high). In S3 state (S3=low, S5=high), VDDQ and VTTREF
voltages are kept on while VTT is turned off and left at high impedance state (high-Z). The VTT output floats and
does not sink or source current in this state. In S4/S5 states (S3=S5=low), all of the three outputs are turned off
and discharged to GND according to the discharge mode selected by MODE pin. Each state code represents as
follow; S0 = full ON, S3 = suspend to RAM (STR), S4 = suspend to disk (STD), S5 = soft OFF. (See Table 1)
Table 1. S3/S5 Power State Control
STATE S3 S5 VREF VDDQ VTTREF VTT
S0 HI HI ON ON ON ON
S3 LO HI ON ON ON OFF(High-Z)
S4/S5 LO LO OFF OFF(Discharge) OFF(Discharge) OFF(Discharge)
MODE Pin Configuration
The TPS51916 reads the MODE pin voltage when the S5 signal is raised high and stores the status in a register.
A 15-μA current is sourced from the MODE pin during this time to read the voltage across the resistor connected
between the pin and GND. Table 2 shows resistor values, corresponding control mode, switching frequency and
discharge mode configurations.
Table 2. MODE Selection
RESISTANCE BETWEEN CONTROL SWITCHING
MODE NO. DISCHARGE MODE
MODE AND GND (kΩ) MODE FREQUENCY (kHz)
7 200 400
Tracking
6 100 300
D-CAP™
5 68 300
4 47 400
Non-tracking
3 33 500
2 22 670
D-CAP2™
1 12 670
Tracking
0 1 500
Discharge Control
In S4/S5 state, VDDQ, VTT, and VTTREF outputs are discharged based on the respective discharge mode
selected above. The tracking discharge mode discharges VDDQ output through the internal VTT regulator
transistors enabling quick discharge operation. The VTT output maintains tracking of the VTTREF voltage in this
mode. (Please refer to Figure 29) After 4 ms of tracking discharge operation, the mode changes to non-tracking
discharge. The VDDQ output must be connected to the VLDOIN pin in this mode. The non-tracking mode
discharges the VDDQ and VTT pins using internal MOSFETs that are connected to corresponding output
terminals. The non-tracking discharge is slow compared with the tracking discharge due to the lower current
capability of these MOSFETs. (Please refer to Figure 30)
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