TPS7A78 Low-Dropout (LDO) Linear Regulator

Texas Instruments TPS7A78 Low-Dropout (LDO) Linear Regulator improves the overall efficiency and standby power in power supplies in an easy-to-use, non-magnetic approach to AC/DC conversion. The TPS7A78 uses a capacitor-drop architecture to lower the AC source voltage before actively clamping the rectified voltage. The device then regulates this rectified voltage down to the application-specific operating voltage. The device's unique architecture reduces the standby power to just a few 10s of milliwatts. The TPS7A78 switched-capacitor stage reduces power losses by stepping down the rectified input voltage by a factor of four and increasing the output-to-input current by the same ratio, as given by P_IN ≅ P_OUT and V_IN ≅ V_OUT × 4. Compared to a traditional capacitor-drop (cap-drop) stage, this step-down reduces input current, thus minimizing the capacitance value needed.