Programmable buck-boost converter targets smartphones

September 06, 2016 // By Nick Flaherty
Fairchild Semiconductor has launched a 2.5A, 1.8MHz digitally programmable buck-boost regulator for the power supplies used in smartphones, tablets and other battery-powered mobile devices.

The FAN49103 is a high efficiency buck-boost switching mode regulator which accepts input voltages either above or below the regulated output voltage. Using full-bridge architecture with synchronous rectification, the FAN49103 is capable of delivering up to 2.5 A while regulating the output at 3.4 V. It provides a seamless transition between step-up and step-down modes to reduce output disturbances and the output voltage and operation mode of the regulator can be programmed through an I2C interface.

At moderate and light loads, Pulse Frequency Modulation (PFM) is used to operate the device in power-save mode to maintain high efficiency and still exhibit excellent transient response during load steps, with a 24 µA quiescent current. At moderate to heavier loads or Forced PWM mode, the regulator switches to PWM fixed-frequency control. While in PWM mode, the regulator operates at a nominal fixed frequency of 1.8 MHz, which allows for reduced external component values.

"Our FAN49103 is an ideal buck-boost for virtually any smartphone, tablet or mobile device that can really benefit from the precious board space freed up by its extremely small solution size, which is 84 percent smaller than its closest competitor,” said Richard Lu, Vice President of Mobile Solutions for Fairchild. “The FAN49103 can also solve the excessive heat and brownout issues that designers of mobile devices strive to overcome.”