The small DC/DC converters have an integrated coil and control IC.torex Semiconductor explains that a power supply circuit can be constructed by adding a ceramic capacitor and a resistor for voltage setting to the external components. This can reduce space requirements for board areas and shorten development time. Integrating a coil simplifies board layout, says the company, to minimise radiation noise and problems with circuit operation.

Input voltage is 3.0 to 36V (absolute maximum ratings 40V) and switching frequency is 2.2MHz. The DC/DC converters have a built-in 0.75V standard voltage supply and the output voltage can be set from 1.8 to 5.0V with an external resistance. The control system can be selected from PWM control (XDL605) or PWM/PFM automatic switching control (XDL606).

The soft-start time has been internally set to 2.0ms (typical), but can be optionally set by connecting a resistance and capacity to the EN/SS pin. The power-good function allows the output voltage to be monitored. Sequence control can be performed with a combination of the soft-start time and power-good function.

The coil and control IC are encapsulated in a DFN3625-11B small leadless package, with exterior dimensions of 2.5 x 3.6 x 1.55mm. The company claims they are the among the world’s smallest class of coil-integrated DC/DCs compliant with AEC-Q100.

The package uses a wettable flank structure. Fillets are formed at the side of the terminal, allowing automatic visual inspections of solder joints to be performed.