Using full-bridge architecture with synchronous rectification, the FAN49103 can output up to 2.5A while regulating the output at 3.4V. It exhibits seamless transition between step-up and step-down modes reducing output disturbances. The output voltage and operation mode of the regulator can be programmed through an I ²C interface.
At moderate and light loads, Pulse Frequency Modulation (PFM) is used to operate the device in power-save mode to maintain high efficiency. In PFM mode, the part still exhibits excellent transient response during load steps. 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.
24 µA Typical PFM Quiescent Current
Above 95% Efficiency
Total Layout Area = 11.61 mm ²
Input Voltage Range: 2.5 V to 5.5 V
Maximum Continuous Load Current:
2.5 A at VOUT=3.4 V, VIN=3.6 V
2 A at VOUT=3.4 V, VIN=2.5 V
I²C Compatible Interface
Programmable Output Voltage:
2.8 V to 4.0 V in 25 mV Steps
1.8 MHz Fixed-Frequency Operation in PWM Mode
Automatic / Seamless Step-up and Step-down Mode Transitions
Forced PWM and Automatic PFM/PWM Mode Selection
0.5 µA Typical Shutdown Current
The FAN49103 can reduce thermal issues by providing a system power rail at the lowest possible voltage, reducing or eliminating heatsinks. Fast transient response counters brownouts by enabling larger pulsed loads to be supported, which reduces the effect of battery droop. It supports large loads up to 2.5A DC and can maintain a constant regulated output over the entire battery range so the system will operate normally despite battery sags.
The FAN49103 comes in a 20-bump WLCSP package 1.6 x 2.0mm.