2 Proposed Application Method for Better System Performance

Figure 2-1 shows the proposed application method using the TPS62810 for better load transition performance and higher efficiency. The MODE or SYNC pin is not fixed to a single voltage level (high or low) in this case and is directly controlled by SSD controller based on the system load conditions. The goal is to operate in Auto Mode at light load condition for higher efficiency and immediately change to FPWM from Auto Mode before the load switches to heavy load from light load condition using the control signal from SSD controller.

Figure 2-1 Proposed Application Method

Figure 2-2 shows a timing sequence from the host to the SSD controller, and the red line represents the wake-up signal from the host while the blue line indicates actual system load. As shown in Figure 2-2, actual system load starts to increasing 7ms later after receiving this wake-up signal from the host. The TPS62810 gets this wake-up signal from the SSD controller directly to control the MODE or SYNC pin of the TPS62810, and the TPS62810 operates in FPWM from Auto Mode at point A to have better load transient performance with lower output voltage ripple before the system load goes up at point B.

When the SSD system enters idle mode, the SSD controller receives a signal from the host at point C. The system then switches to idle mode 2ms later at point D. After point D, the TPS62810 switches from FPWM to Auto Mode to achieve better ripple performance and higher efficiency under light load conditions. All of these operations are triggered by a control signal directly from the SSD controller.

The key point is that the SSD controller receives a signal from the host prior to any actual system load transition between light and heavy states, which can be utilized to trigger a mode change in the TPS62810.

Figure 2-2 Timing Sequence from the Host to SSD Controller