The ST1PS01 uses synchronous rectification to provide an efficiency of 92% at 400mA full load and 95% when delivering just 1mA. Power-saving design features keep the quiescent current to 500nA and include a low-power voltage reference. There is also a pulse-frequency counter for controlling converter current at light load, with two high-speed comparators to help minimize output ripple.
Integrated feedback-loop compensation, soft-start circuitry, and power switches ensure a space-saving solution that requires just a few small-outline passives to complete the circuit. The typical inductor value is 2.2µH. In addition, output-voltage selection logic not only saves external voltage-setting components but also gives flexibility to configure modules digitally at manufacture or let the host system change the output voltage on the fly. Eight variants, each with four optional output-voltage settings, allow a choice of regulated outputs from 3.3V to 0.625V. All models feature a Power-good indicator.
A wide input-voltage range, from 1.8V to 5.5V, further enhances flexibility for designers by allowing various battery chemistries or configurations as simple as a single lithium cell and extending runtime as the battery discharges. ST1PS01 regulators are also ideal for devices powered from energy-harvesting systems and feature a low noise-architecture that allows use in noise-sensitive applications.
An evaluation board, STEVAL-1PS01EJR, is available and the ST1PS01 regulators are now in full production, packaged as 400µm-pitch flip-chip devices measuring 1.11mm x 1.41mm, and priced from $0.686 for orders of 1000 pieces.