ZHCS264E MAY 2011 – July 2018 TPS51206
PRODUCTION DATA.
Because the TPS51206 device is a linear regulator, the VTT current flows in both source and sink directions, thereby dissipating power from the device. When the device is sourcing current, the voltage difference between VVLDOIN and VVTT times IVTT (VTT current) current becomes the power dissipation as shown in Equation 1.
In this case, if the VLDOIN pin is connected to an alternative power supply lower than the VDDQ voltage, overall power loss can be reduced. For the sink phase, VTT voltage is applied across the internal LDO regulator, and the power dissipation can be calculated by Equation 2.
Maximum power dissipation allowed by the package is calculated by Equation 3.
where