30V Operation p Low Power Consumption p Step-down DC/DC Controller IC XC9252 Series Printer GPS Navigation SALES .05 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 (CL). A 0.8V reference voltage source is incorporated, and the output voltage can be set freely from 1.5V using external resistors (RFB1, RFB2). 280kHz to 550kHz can be selected for the switching frequency by connecting an external resistor to the ROSC pin. The generation of unneeded 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. 2.6 ±0 STB ±0 .05 2.9 Surveillance Camera New Product Leaflet USP-10B SALES Achieves high efficiency at light loads 1 Microcomputers have a standby mode to reduce battery consumption, and the efficiency of the DC/DC converter plays an important role in this. ■Example Capable of operation from a low voltage 2 Output is not shut down even when the battery voltage drops suddenly due to environment or other factors. ■Example Even though a car is stopped, some power from a battery is consumed. Dramatic voltage drop happens due to a cranking or a cold cranking. ■XC9252 Advantage ■XC9252 Advantage In this case, the low power consumption feature is important for a power management IC. Even though an input voltage drops dramatically. XC9252 can ease the impact because the power SW for XC9252 is P-FET. Input Voltage (MIN.) 3.0V ⇒ XC9252; Iq:30μA, PFM control is selectable. Waveform when VIN is lower than V_nominal Efficiency vs. Output Current f=460kHz, VIN=13V & 16V, VOUT=5.7V, IOUT=2.5A VIN=5V, VOUT=5V, IOUT=500mA VIN VIN (red): 1V/div XC9252 VOUT (light green): 1V/div Low Input Current=0.6mA (16V), 0.5mA (13V) VOUT (blue) of regular DC/DC with internal N-ch driver VIN=5.0V VOUT=4.85V XC9252 (P-ch Driver) ⇒Lower Dropout Efficiency: EFFI (%) 100 80 Buck with N-ch driver VOUT=4.25V GND 60 40 VIN=13V (PWM) VIN=16V (PWM) VIN=13V (PWM/PFM) VIN=16V (PWM/PFM) 20 0 0.0001 0.001 0.01 0.1 Output Current: IOUT (A) 1 10 Most high-withstand voltage DC/DC converters use an N-ch driver IC. When an input voltage less than the set voltage is applied to an N-ch driver IC, the output voltage drops dramatically due to the MAX Duty limit. The XC9252 Series uses a P-ch driver. When an input voltage lower than the set voltage is applied, the MAX Duty limit is 100% and the output voltage drop is smaller than with an N-ch driver. Memory protection when voltage drops due to cranking of vehicle Supply from backup power supply of industrial equipment. Features Input Voltage Range Load Dump Transients 3.0V ~ 30V ( Maximum Rating: 36V) 46V, 400ms FB Voltage Supply Current 0.8V (±2.0%) 30μA (@300kHz) Oscillation Frequency 280kHz ~ 550kHz (External Resistor) Ext. CLK Synchronization ±25% of the internal CLK Control Method PWM (Mode: H) , PWM/ PFM (Mode: L) Soft-start Protection Circuit External set (External C) Over current limit (External Resistor) Integral latch protection Auto-return Packages Thermal shutdown TSSOP-16, USP-10B Environmentally friendly EU RoHS Compliant, Pb Free www.torex.co.jp/english/ October 2013 ② ● Values shown in this sheet can be changed without any prior notice.