Power Supply Voltage Drop Improvement using Boost Converter in Smartphone Systems

There has been a rapid increase in smartphone applications and features, which require high performance to support them. This causes current consumption to increase, resulting in the system voltage drop and leading to power problems with the power of the smartphone. A representative example is the sudden power off problem caused by Under Voltage Lock Out (UVLO), which is a serious problem because it can be immediately recognized by the user. To solve this problem, the main approach is often to lower the clock speed of the main processing unit, but this has the problem of decreasing performance. This paper proposes a circuit that compensates for voltage drop caused by momentary peak current by using a boost converter to drive the gate of the buck converter. To verify the proposed circuit, the DC resistance of the smartphone was modeled. Simulation results confirm that the circuit reduces the voltage drop by 298mV when a peak current of 10A occurs. This improvement ensures the power stability by preventing UVLO without limiting the performance of the main processing unit.