R5543 Series

18mΩ ON Resistance 3A Load Switch IC

The R5543 Series is a CMOS-based dual supply voltage load switch IC. The R5543 Series is an ideal switch for supplying the power from the secondary power source such as the output of a step-down DC/DC converter to the load circuit. A built-in Nch. transistor with typically 18 mΩ ON resistance allows the R5543 Series to provide a low dropout voltage and prevents the reverse current during shutdown mode. Internally, a single IC consists of an internal voltage step-up circuit, a soft-start circuit, a thermal shutdown circuit, a chip enable circuit and a UVLO circuit.

The gate voltage of Nch. driver transistor is supplied by a soft-start circuit. The soft-start circuit is supplied by the external power source (VBIAS). Soft-start time is adjustable by connecting an external capacitor. The R5543 Series is offered in an ultra-small 6-pin DFN(PL)1216-6G package which achieve the smallest possible footprint solution on boards where area is limited.