FAN5355UC00X

The FAN5355 device is a high-frequency, ultra-fast transient response, synchronous step-down DC-DC converter optimized for low-pover applications using small, low-cost inductors and capacitors. The FAN5355 sLpports to 800 mA ,1 A, or 1.1 A load current. The device is ideal for mobile phones and similar portable applications powered by a single-cell Lithium-Ion battery. Wth an output-voltage range adjustable via interface from 0.75 V to 1.975 V, the deuce supports low-voltage DSPs and processors, core power supplies, and memory modules in smart phones, PDAs, and handheld computers. The FAN5355 operates at 3 MHz (nominal) fixed switching frequency using either its hternal oscillator an external SYNC frequency. During light-load corxffons, the reguator includes a PFM rrnde to enhance light-load efficiency. The regulator transitions smoothly between PWM and PFM modes With no glitches on VOUT. In hardware shutdown, the current consumption is to less than 200 nA. The serial interface is compatible With Fast/Standard and High-Speed mode 12C specifications, allowing transfers up to 3.4 Mbps. This interface is used for dynamic voltage scaling With 12.5mV voltage steps for reprogramming the mode Of operation (PFM or Forced PWM), or to disable/enable the output voltage. The chip's advanced protection features inchlde short-circuit protection and current and temperature limits. During a sustained over-current event, the IC shuts down and restarts after a delay to reduce average power dissipation into a fault. During startup, the IC controls the output slew rate to minirnize input current and output overshoot at the end Of soft start. The IC maintains a consistent soft-start ramp, regardless Of output load during startup. The FAN5355 is available in 10-lead MLP (3x3 mm) and 12-bump WLCSP packages.

• 93% Efficiency at 3 MHz
• 800 mA, 1 A, or 1.1 A Output Current
• 12C -Cornpatible Interface up to 3.4 Mbps
• 6-bit VOUT Programmable from 0.75 V to 1.975 V
• 2.7 V to 5.5 V Input Voltage Range
• 3 MHz Fixed-Frequency Operation
• Excellent Load and Line Transient Response
• Small Size, 1 uH Inductor Solution
• +2% PWM DC voltage Accuracy
• 35 ns Minimum On-Tirne
• High-Efficiency, Low-Ripple, Light-Load PFM
• Smooth Transition between PVVM and PF M
• 37 uA Operating PFM Quiescent Current
• Pin-selectable or Programmable Output Voltage
• On-the-Fly External Clock Synchronization
• ID-lead MLP (3 x 3 mm) or 12-bump CSP Packages