The ADP5134 combines two high performance buck regulators and two low dropout (LDO) regulators. It is available in a 24-lead 4 mm × 4 mm LFCSP. The high switching frequency of the buck regulators enables tiny multilayer external components and minimizes the board space. When the MODE pin is set to high, the buck regulators operate in forced pulse-width modulation (PWM) mode. When the MODE pin is set to low, the buck regulators operate in PWM mode when the load is above a predefined threshold. When the load current falls below a predefined threshold, the regulator operates in power save mode (PSM), improving the light load efficiency. The two buck regulators operate out of phase to reduce the input capacitor requirement. The low quiescent current, low dropout voltage, and wide input voltage range of the ADP5134 LDO regulators extend the battery life of portable devices. The ADP5134 LDO regulators maintain power supply rejection greater than 60 dB for frequencies as high as 10 kHz while operating with a low headroom voltage of 500 mV.