XC9228 series

Dynamically Adjustable 500mA Step down DC/DC Converter

• XC9228 PWM only
• XC9229 PWM/PFM (Auto Switching)
• 92% Efficiency
• Quiescent Current: Only 18μA (typ)

The XC9228/29 series are synchronous-rectification type DC/DC converters that allows the output voltage to be adjusted via an external voltage reference (Vref) input. The XC9228/9 has a built in 0.6½ P-channel driver transistor and 0.7½ N-channel switching transistor. The IC is designed to allow the use of ceramic capacitors, and provide a high efficiency (92%). A stable power supply with output currents of 500mA can be configured using only a coil and two capacitors connected externally. Minimum operating voltage of the series is 2.0 V. With a built-in oscillator, the 's switching frequency is selectable from 600kHz and 1.2MHz to make available the frequency best suited to your particular application. As for operation mode, the XC9228 series is a PWM control type, while the XC9229 series has automatic PWM/PFM switching control, allowing fast response, low ripple and high efficiency over the full range of current load. During stand-by all circuits are shutdown to reduce current consumption to less than 1.0A.

The soft start and current control functions are internally optimized.

Features:

• Input Voltage: 2.0 ~ 6.0V
• Output Voltage: Vout = Vref x 1.2 (A type), Vout = Vref x 2.4 (B type)
• Output Current: 500mA
• Oscillator Frequency: 600kHz, 1.2 MHz
• Current Limit Circuit 700mA
• Ceramic Capacitor Compatible
• Small SOT23-5 USP6B (2.0 x 1.8 x 0.8mm)

Packages: SOT-25 , USP-6B