In power converters, extended soft-start duration and loop compensation typically require large capacitors. However, off-chip capacitors increase packaging cost and peripheral complexity, reducing system reliability. Although on-chip integration is viable, capacitance density is strictly limited by process constraints and chip area, thereby restricting compensation network flexibility and soft-start time adjustment. To address these limitations, a highly integrated DC-DC converter with a simplified off-chip environment is proposed. For internal loop compensation, an improved scheme employing a transconductance amplifier achieves equivalent capacitance amplification, enhancing stability and design flexibility. For on-chip soft-start, a capacitor-free method utilizing charging current diversion is presented, enabling prolonged soft-start time within a limited area to suppress inrush current effectively. The converter is implemented in a 0.18-µm BCD process with an area of 1.73 mm². Measurement results demonstrate that, at a 5 V/2 A output rating, the converter achieves an efficiency exceeding 80% over a load range of 1 mA to 2 A, with a peak efficiency of 95.1%. Under a load step change, the output voltage overshoot and undershoot are less than 180 mV, and the recovery time is approximately 200 μs, indicating good stability of the converter. The measured start up time is approximately 4.8 ms.