DLPS039F December 2015 – April 2019 TPS99000-Q1
Main asynchronous digital logic reset (DVDD_RSTZ) – Monitor of the main power of the 3.3 V power supply input to the TPS99000-Q1. This monitor output is used as an asynchronous reset for all of the digital logic inside TPS99000-Q1.
The PROJ_ON pin is the main on/off switch for DLP subsystem. 1 is ON, 0 is OFF. Once DVDD_ARSTZ is released, TPS99000-Q1 will begin sampling the PROJ_ON pin. If it is low, system stays in the OFF state. If it goes high, TPS99000-Q1 begins to progress through the power-on process.
The TPS99000-Q1 includes a VMAIN brown out monitor function. A voltage monitor observes the voltage on the VMAIN input pin, as shown in Figure 34. The Zener may be necessary for over voltage protection of the pin, in case the voltage being monitored has the potential to go high, such as a battery input.
Either PROJ_ON or VMAIN may be used to turn the system on and off, and doing so will remove power to the DLPC230-Q1. For fast control of turning the display on and off without removing power to the DLPC230-Q1, change the operating mode of the DLPC230-Q1 embedded software between 'Standby' and 'Display'.
This monitor is used to provide the DLP subsystem with an early warning that power to the unit is going away. The system will park the DMD mirrors and proceed to a ready for power-off state if the VMAIN input voltage falls below a fixed threshold. External resistors should be used to divide the input power rail. Once a VMAIN brown out occurs, the main power rails to the TPS99000-Q1 must remain within their operating ranges until the TPS99000-Q1 power-down is complete.
The main power rails to the chipset (6 V, 3.3 V, 1.8 V and 1.1 V) are monitored with real time power monitors as well. Each of these monitors is logically 'OR'ed together to produce the pwrgood2 signal in Figure 35.
Additionally, all power within the TPS99000-Q1 can be monitored by the ADC function. DLPC230-Q1 software configures the ADC block to collect all voltage information in the system each frame. Any gross out of specification issues are captured and reported as system errors in the DLPC230-Q1 system status.