XC9224 Series

1A Driver Transistor Built-in Step-Down DC/DC Converters

The XC9224 series are synchronous step-down DC/DC converters with a 0.21Ω (TYP.) P-ch driver transistor and a synchronous 0.23Ω(TYP.) N-ch switching transistor built-in. A highly

efficient and stable current can be supplied up to 1.0A by reducing ON resistance of the built-in transistor. With a high switching frequency of 1MHz or 2MHz, a small inductor is selectable; therefore, the XC9224 series are ideally suited to applications with height limitation such as HDD or space-saving applications. Current limit value can be chosen either 1.2A (MIN.) when the LIM pin is high level, or 0.6A (MIN.) when the LIM pin is low level for using the power supply which current limit value differs such as USB or AC adapter.

With the MODE/SYNC pin, the XC9224 series provide mode selection of the fixed PWM control or automatically switching current limit PFM/PWM control. As for preventing unwanted switching

noise, the XC9224 series can be synchronized with an external clock signal within the range of ± 25% toward an internal clock signal via the MODE/SYNC pin. For protection against heat damage of the ICs, the XC9224 series build in three protection functions: integral latch protection, thermal shutdown, and short-circuit protection. With the built-in UVLO (Under Voltage Lock Out) function, the internal P-channel driver transistor is forced OFF when input voltage becomes 1.8V or lower. The XC9224B series’ detector function monitors the discretional voltage by external resistors.

Typical Application Circuit


Input Voltage Range 2.5V~6.0V
Output Voltage Range 0.9V~VIN,(Can be set freely with 0.8V [±2%] of reference voltage by the external resistors.)
Oscillation Frequency 1MHz,2MHz (Accuracy ±15%)
Output Current 1.0A
Maximum Current Limit 0.6A(MIN.)0.9A(MAX.)LIM pin=“L”
1.2A(MIN.)2.0A(MAX.)LIM pin=“H”
Control Methods PWM/PFM externally switching,Synchronized with an external clock signal
Protection Circuits Thermal shutdown,Integral latch method (over current limit),Short-circuit protection
Soft-Start 1ms (TYP.) inernally set
Voltage Detector B type(with VD function),0.712V detect, N-ch open drain,D type(without VD function)



Quality Reports


QuestionWhat is the soft-start function?

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

QuestionWhat is the standby current?

The current that flows through the IC in the standby mode. The standby mode means the state where the IC has been turned off by the CE function.