The TPS53128 is a dual, adaptive on-time D-CAP2TM mode synchronous buck controller. The part enables system designers to cost effectively complete the suite of various end equipment's power bus regulators with a low external component count and low standby consumption. The main control loop for the TPS53128 uses the D-CAP2TM Mode topology which provides a very fast transient response with no external component. The TPS53128 also has a proprietary circuit that enables the device to adapt not only low equivalent series resistance (ESR) output capacitors such as POSCAP/SP-CAP, but also ceramic capacitor. The fixed frequency emulated adaptive on-time control supports seamless operation between PWM mode at heavy load condition and reduced frequency operation at light load for high efficiency down to milliampere range. The part provides a convenient and efficient operation with conversion voltages from 4.5 V to 24 V and output voltage from 0.76 V to 5.5 V.