1FEATURES
• Fixed 3.3-V Output
• 4.5-V to 28-V Wide Input Voltage Range
• Up to 1.7-A Maximum Continuous Output
Loading Current
• Pulse Skipping Mode to Achieve High Light
Load Efficiency
• Over 80% Efficiency at 10-mA Loading
• Adjustable 50-kHz to 1.1-MHz Switching
Frequency Set by an External Resistor
(Leave pin ROSC floating. Set frequency to
120 kHz and ground connection to 70 kHz)
• Peak Current-Mode Control
• Cycle-by-Cycle Over Current Protection
• Frequency Spread Spectrum and Switching
Node Anti-Ringing to Ease EMI Issue
• External Soft Start
• Available in SOIC8 Package

APPLICATIONS
• 5-V, 9-V, 12-V and 24-V Distributed Power
Systems
• Consumer Applications Such as Home
Appliances, Set-Top Boxes, CPE Equipment,
LCD Displays, Peripherals, and Battery
Chargers
• Industrial and Car Entertainment Power
Supplies

DESCRIPTION
The TPS5403 is a monolithic non-synchronous buck regulator with wide operating input voltage range from 4.5 V
to 28 V. Current mode control with internal slope compensation is implemented to reduce component count.
TPS5403 also features a light load pulse skipping mode, which allows for a power loss reduction from the input
power supply to the system at light loading.
The switching frequency of the converters can be set from 50 kHz to 1.1 MHz with an external resistor.
Frequency spread spectrum operation is introduced for EMI reduction.
LX anti-ringing is added to address high frequency EMI issues.
A cycle-by-cycle current limit with frequency fold back protects the IC at over loading condition.