The APW7093 is a reversible energy flow, constant-offtime, pulse-width modulated (PWM), step-down DC-DC converter. It is ideal for use in notebook and sub-notebook computers that require 1.1V to 5V active termination power supplies. This device features an internal PMOS power switch and internal synchronous rectifier for high efficiency and reduced component count. The internal 90mW PMOS power switch and 60mW NMOS synchronous-rectifier switch easily deliver continuous load currents up to 3A. The APW7093 accurately tracks an external reference voltage, produces an adjustable output from 1.1V to VIN, and achieves efficiencies as high as 94%. The APW7093 uses a unique current-mode, constantoff-time, PWM control scheme that allows the output to source or sink current. This feature allows energy to return to the input power supply that otherwise would be wasted. The programmable constant-off-time architecture sets switching frequencies up to 1MHz, allowing the user to optimize performance trade-offs between efficiency, output switching noise, component size, and cost. The APW7093 features an adjustable soft-start to limit surge currents during startup, a 100% duty-cycle mode for lowdropout operation, and a low-power shutdown mode that disables the power switches and reduces supply current below 1µA. The APW7093 is available in a 32-pin TQFN with an exposed backside pad or a 16-pin SSOP.