SLVSE46A November 2017 – January 2018 TPS65680
The TPS65680 requires a low-voltage input supply VIN (typical 3.7V) and high and low gate driver supplies VGH and VGL1 and VGL2. VGL2 (power pad) may be connected to a dedicated most negative gate driver supply or it must be connected to the VGL1 pin. Supplies may be applied in any order during power-up. The typical power-up and power-down sequence is shown in Figure 6. The first voltage rail to be applied to the device is typically battery voltage or a pre-regulated 3.3V supply, VIN. The second rail is the negative gate driver supply VGL2, followed by VGL1, and finally VGH.
The power-down and panel discharge sequence is triggered by a falling edge on the LS_CNTRL pin. After a delay of D1, active discharge of the VGH supply is enabled. At this point, all external rails can be powered down, typically by disabling them simultaneously.