FTM Board Club
Fairchild Semiconductor
Integrated Synchronous DC-DC Buck Converter.

The FAN4603 Evaluation Board is a compact circuit which includes Fairchild’s FAN4603MM fully integrated synchronous buck converter in a 6-lead MLP package.

The converter is offered in an ultra small, 4 x 2.5mm “Solder-and-Play” package that requires no external components. The board also features an on-board active load circuit and additional footprints to accommodate external input/output capacitors. The FAN4603 Evaluation Board provides probe access points to all key circuit nodes so that electrical characteristics can be measured with ease.

The FAN4603 is a fully integrated synchronous DC/DC buck converter that provides up to 600mA of output current over an input voltage ranging from 2.3V to 5.5V. It provides a fixed output voltage level ranging from 1.2V to 1.8V. Other voltage options are available on request. The FAN4603 converter is offered as an ultra-miniature “Solder and Play” solution that requires no external components and is able to achieve a DC accuracy of ±4% PWM and an output ripple less than 12mV. Total footprint is 4.0 x 2.5mm with a maximum height of 1mm. It can be used in small battery-powered devices and applications with distributed DC POL requirements. At moderate and light loads, pulse frequency modulation is used to operate the device in power-save mode with a typical quiescent current of 35µA. Even with such a low quiescent current, the part exhibits excellent transient response during large load swings. At higher loads, the system automatically switches to fixed-frequency control. In shutdown mode, the supply current drops below 2µA, reducing power consumption.


• Solder and Play DC/DC Converter;No External Components Required
• Up to 91% Efficiency
• 500mA Output Current Capability
• 2.3V to 5.5V Input Voltage Range
• Fixed Output Voltages from 1.2V to 1.8V
• 35µA PFM Quiescent Current
• Best-in-Class Load and Line Transient Response
• ±4% PWM DC Voltage Accuracy
• No External Components Required
• High-Efficiency, Low-Ripple, Light-Load PFM
• Thermal Shutdown (TSD), Under-Voltage Lockout,(UVLO), and Short-Circuit (SCP) Protection
• 4.0 x 2.5mm MLP Package
• Maximum Height: 1.1mm