XC9263 Series

18V Operation 0.5A Synchronous Step-Down DC/DC Converters

The XC9263 series are 18V operation synchronous step-down DC/DC converter ICs with a built-in P-channel MOS driver transistor and N-channel MOS switching transistor. The XC9263 series has operating voltage range of 3.0V~18.0V and high-efficiency power supply up to an output current of 0.5A. Low ESR capacitors such as ceramic capacitors can be used for the load capacitor (CL).

A 0.75V reference voltage source is incorporated in the IC, and the output voltage can be set to a value from 1.0V to 15.0V using external resistors (RFB1, RFB2).500kHz or 1.2MHz or 2.2MHz can be selected for the switching frequency. 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 is internally set to 1ms (TYP.), but can be adjusted to set a longer time using an external resistor and capacitor.With the built-in UVLO function, the driver transistor is forced OFF when input voltage becomes 2.7V or lower.The output state can be monitored using the power good function.

Internal protection circuits include over current protection, short-circuit protection, and thermal shutdown circuits to enable safe use.

Typical Application Circuit


Input Voltage Range 3.0V~18.0V
(Absolute Maximum Rating:20V)
Output Voltage Range 1.0V~15.0V(VFB=0.75V±1.5%)
Output Current 500mA
Efficiency Efficiency85%@12V→5V、1mA
Oscillation Frequency 500kHz、1.2MHz、2.2MHz
Soft-Start Adjustable by RC
Control Methods PWMControl
Protection Circuits Over Current Protection
Automatic Recovery
Integral Latch Method
Thermal Shutdown
Capacitor Low ESR Ceramic
Operating Ambient Temperature -40℃~+105℃



Technical Document

Quality Reports


QuestionWhat is the soft-start function?

The function to soften the rise to prevent the inrush current.

QuestionWhat does the FB product mean?

An IC for which any output voltage can be set by the reference voltage of the FB pins and the external dividing resistor. The output voltage is determined by the RFB1 and RFB2 values, using the following formula: VOUT = Vref × (RFB1 + RFB2)/RFB2

QuestionHow does UVLO (under voltage lockout) work?

This circuit forcibly turns off the driver transistor when VIN drops below the UVLO voltage. If the input voltage recovers to the value which is equal to the specified value or more, UVLO will be released to resume the switching operation. It is resumed by the soft-start function. The paused state by UVLO is not the shutdown. The pulse output is stopped, but the internal circuit is operating.