onsemi FAN53555UC18X

The FAN53555 is a step-down switching voltage regulator that delivers a digitally programmable output from an input voltage supply of 2.5 V to 5.5 V. The output voltage is programmed through an I²C interface capable of operating up to 3.4 MHz. Using a proprietary architecture with synchronous rectification, the FAN53555 is capable of delivering 5 A continuous at over 80% efficiency, while maintaining over 80% efficiency at load currents as low as 10 mA. Pulse currents as high as 6.5 A can be supported by the 05 option. The regulator operates at a nominal fixed frequency of 2.4 MHz, which reduces the value of the external components to 330 nH for the output induction and as low as 20 μF for the output capacitor. Additional output capacitance can be added to improve regulation during load transients without affecting stability. Inductance up to 1.2 μH may be used with additional output capacitance. At moderate and light loads, Pulse Frequency Modulation (PFM) is used to operate in Power-Save Mode with a typical quiescent current of 60 μA. 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, operating at 2.4 MHz. In Shutdown Mode, the supply current drops below 1 μA, reducing power consumption. PFM Mode can be disabled if constant frequency is desired. The FAN53555 is available in a 20-bump, 1.6×2 mm, WLCSP.

• Fixed-Frequency Operation: 2.4 MHz
• Best-in-Class Load Transient
• Continuous Output Current Capability: 5 A
• Pulse Current Capability: 6.5 A (05 Option)
• 2.5 V to 5.5 V Input Voltage Range
• Digitally Programmable Output Voltage:
  • 00/01/03/05/08/18 Options: 0.6 - 1.23 V in 10 mV Steps
  • 04/042/09/ Options: 0.603 - 1.411 V in 12.826 mV Steps
  • 23 Option: 0.60 - 1.3875 V in 12.5 mV Steps
  • 24 Option: 0.603 - 1.420 V in 12.967 mV Steps
  • 13 Option: 0.8 - 1.43 V in 10 mV Steps
• Programmable Slew Rate for Voltage Transitions
• I²C-Compatible Interface Up to 3.4 Mbps
• PFM Mode for High Efficiency in Light Load
• Quiescent Current in PFM Mode: 60 μA (Typical)
• Internal Soft-Start
• Input Under-Voltage Lockout (UVLO)
• Thermal Shutdown and Overload Protection
• 20-Bump Wafer-Level Chip Scale Package (WLCSP)

• Application, Graphic, and DSP Processors - ARM, Krait, OMAP, NovaThor, ARMADA
• Hard Disk Drives
• Tablets, Netbooks, Ultra-Mobile PCs
• Smart Phones
• Gaming Devices