1FEATURES
• Input Voltage Range from 3 V to 20 V
• Fixed 600-kHz Switching Frequency
• High- and Low-Side FET RDS(on) Current
Sensing
• Programmable Thermally Compensated OCP
Levels
• Programmable Soft-Start
• 591-mV, 1% Reference Voltage
• Voltage Feed-Forward Compensation
• Supports Pre-Biased Output
• Frequency Spread Spectrum
• Thermal Shutdown Protection at 145°C
• 10-Pin 3 mm × 3 mm SON Package with
Ground Connection to Thermal Pad

CONTENTS
Device Ratings 2
Electrical Characteristics 3
Device Information 8
Application Information 10
Additional References 13

APPLICATIONS
• POL Modules
• Printer
• Digital TV
• Telecom

DESCRIPTION
The TPS40304A is a cost-optimized synchronous buck controller that operates from 3-V to 20-V input. The
controller implements a voltage-mode control architecture with input-voltage feed-forward compensation that
responds instantly to input voltage change. The switching frequency is fixed at 600 kHz.
Frequency Spread Spectrum feature adds dither to the switching frequency, significantly reducing the peak EMI
noise and making it much easier to comply with EMI standards.
The TPS40304A offers design with a variety of user programmable functions, including soft-start, overcurrent
protection (OCP) levels, and loop compensation.
The OCP level is programmed by a single external resistor connected from LDRV pin to circuit ground. During
initial power on, the TPS40304A enters a calibration cycle, measures the voltage at the LDRV pin, and sets an
internal OCP voltage level. During operation, the programmed OCP voltage level is compared to the voltage drop
across the low-side FET when it is on to determine whether there is an overcurrent condition. The TPS40304A
then enters a shutdown and restart cycle until the fault is removed.