4.5-V to 28-V, dual-synchronous buck controller with 100-mA LDOs and flexible external components

The TPS51125A 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 270-kHz VCLK output can be used to drive an external charge pump, generating gate drive voltage for the load switches without reducing the main converter’s efficiency. The TPS51125A supports high efficiency, fast transient response 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 TPS51125A is available in a 24-pin QFN package and is specified from -40°C to 85°C ambient temperature range.