The TPS51123 is a cost effective, dual-synchronous buck controller targeted for notebook system power supply solutions. It provides 5-V and 3.3-V LDOs and requires few external components. The TPS51123 supports high efficiency, fast transient responses and provides a combined power-good signal. Out-of-Audio mode light-load operation enables low acoustic noise at much higher efficiency than conventional forced PWM operation. Adaptive on-time D-CAP control provides convenient and efficient operation. The part operates with supply input voltages ranging from 5.5 V to 28 V and supports output voltages from 2 V to 5.5 V. The TPS51123 is available in a 24-pin QFN package and is specified from -40°C to 85°C ambient temperature range.