R5541K Series Low ON Resistance Nch Load Switch IC NO.EA-319-190108 OUTLINE The R5541K is a CMOS-based dual supply voltage load switch IC. The R5541K 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 m ON resistance allows the R5541K 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 R5541K is offered in an ultra-small 6-pin DFN(PLP)1216-6G package which achieve the smallest possible footprint solution on boards where area is limited. FEATURES Supply Current Typ. 25 A (IOUT = 0 mA) Standby Current Typ. 0.01 A VIN Input Voltage Range 0.6 V to 4.8 V VBIAS Input Voltage Range 2.5 V to 5.5 V Switch ON Resistance Typ. 18 m (VIN = 1.0 V, VBIAS = 5.0 V) Output Current Max. 3 A A single Nch MOSFET Circuit Soft-start Function Thermal Shutdown Circuit Auto-discharge Function (R5541K001D) Package DFN(PLP)1216-6G APPLICATIONS Secondary Power Source for hand-held communication equipments and laptop PCs 1 R5541K NO.EA-319-190108 BLOCK DIAGRAMS R5541K001B Block Diagram R5541K001D Block Diagram SELECTION GUIDE *1 The auto-discharge function is a user-selectable option. Selection Guide Package Quantity per Reel Pb Free Halogen Free Product Name DFN(PLP)1216-6G 5,000 pcs Yes Yes R5541K001 -E2 : Specify the CE Pin Polarity and auto-discharge option. B: Active-High, no auto-discharge function D: Active-High, auto-discharge function *1 Auto-discharge function quickly lowers the output voltage to 0 V, when the chip enable signal is switched from the active mode to the standby mode, by releasing the electrical charge accumulated in the external capacitor. 2