|Input Voltage||2.5 ~ 6.0V|
|Oscillation Frequency||1MHz, 2MHz|
1A Synchronous Step Down DC/DC Converter
The XC9224 series are synchronous step-down DC/DC converters with an integral 0.23Ω (TYP.) P-channel and a synchronous 0.25Ω (TYP.) N-channel switching transistor built-in. Output currents of up to 1.0A can be achieved using a simple circuit.
With switching frequencies of 1.0MHz or 2.0MHz, small inductors can be used, making the series ideally suited to applications where height and PCB area is limited.
The MODE/SYNC pin allows the user to select fixed PWM mode or PFM/PWM auto-switching control. With PFM/PWM control, the XC9224 series selects the best switching mode depending on output load thus ensuring the highest efficiencies from light to heavy loads.
For applications troubled by switching noise, the XC9224 series can be synchronized with an external clock signal via the MODE/SYNC pin. The series automatically operates in PWM mode when synchronized in this way. The series also has a built-in current limiter circuit which enables the user to fix either a 0.5A or a 1.5A threshold thereby ensuring that smaller inductors can be used safely.
A built-in voltage comparator is also available for low battery protection or monitoring the start-up sequence. To prevent an overcurrent state, the IC detects overshoot current by analyzing the voltage difference between the VDD and Lx pin. After an over current state continues for a few millisec’s, the IC’s operation goes into suspension mode and the driver transistor is turned off.
The series also incorporates a thermal shutdown circuit which operates if the IC’s junction temperature reaches 150°C. When the temperature drops to 130°C or less, the IC performs the soft start function and full operation is resumed. In addition the short-circuit protection will shut down the IC when the FB voltage decreases less than half of the setting voltage.