XC9252 Series ETR05038-005 Low Power Consumption Step-down DC/DC Controller IC GENERAL DESCRIPTION The XC9252 series is a 30V operation step-down DC/DC controller IC. The external P-ch driver transistor is used to achieve a stable operation under low input voltage. Low ESR capacitors such as ceramic capacitors can be used for the load capacitor (C ). L A 0.8V reference voltage source is incorporated, and the output voltage can be set freely from 1.5V using external resistors (R , R ). FB1 FB2 280kHz to 550kHz can be selected for the switching frequency by connecting an external resistor to the R pin. The generation of unneeded OSC noise can be reduced by this synchronization with an external CLK within 25% of the internal clock using the MODE/SYNC pin. In automatic PWM/PFM control, the IC operates by PFM control when the load is light to achieve high efficiency over the full load range from light to heavy. The soft start time can be set as desired by adding an external capacitance to the SS pin. With the built-in UVLO function, the driver transistor is forced OFF when input voltage becomes 2.5V or lower. Internal protection circuits include over current protection, short-circuit protection, and thermal shutdown circuits to enable safe use. APPLICATIONS FEATURES Input Voltage Range : 3.0V30V (Absolute MAX. Rating: 36V) Car navigation systems FB Voltage : 0.8V (2%) Car audios Supply Current : 30A ( 300kHz) Oscillation Frequency : 280kHz550kHz (External Resistor) ETC automotives External Clocking Synchronous :25% of the internal clock Control Method : PWM control (MODE:H) PWM/PFM (MODE:L) Soft-Start : External set (External C) Protection Circuits : Over current limit (External Resistor) Automatic Return (XC9252A/B) Integral latch protection (XC9252C) Thermal shutdown Output Capacitor : Low ESR Capacitor Operating Ambient Temperature : -40+105 Packages : TSSOP-16 (XC9252A/C) USP-10B (XC9252B) Environmentally Friendly : EU RoHS Compliant, Pb Free TYPICAL APPLICATION CIRCUIT TYPICAL PERFORMANCE CHARACTARISTICS XC9252x08A(V =12V, V =5.7V, =280kHz) IN OUT OSC L=22 H(CLF12555-220M), C =10 F(GRM32ER71H106KA12L), IN R =300k, C =22F2 (GRM32ER71E226KE15L), OSC L R =50m, PchMOSFET:2SJ668, SBD:CMS15 SENSE 100 90 80 70 60 50 40 30 20 PFM(MODE=L) 10 PWM(MODE=H) 0 1 10 100 1000 10000 Output Current :I mA OUT 1/28 Efficiency :EFFI % XC9252 Series BLOCK DIAGRAM 1) XC9252 Series, Type A 2) XC9252 Series, Type B 3) XC9252 Series, Type C * Diodes inside the circuit are an ESD protection diode and a parasitic diode. 2/28