1FEATURES

2• Input Voltage Range: 4.5 V to 32 V

• Output Voltage Range: 1 V to 12 V

• Selectable Light Load Operation

(Continuous / Auto Skip / Out-Of-Audio™ Skip)

• Programmable Droop Compensation

• Voltage Servo Adjustable Soft Start

• 200-kHz to 1-MHz Fixed-Frequency PWM

• Selectable Current/ D-CAP™ Mode

Architecture

• 180° Phase Shift Between Channels

• Resistor or Inductor DCR Current Sensing

• Adaptive Zero Crossing Circuit

• Powergood Output for Each Channel

• OCL/OVP/UVP/UVLO Protections

(OVP Disable Option)

• Thermal Shutdown (Non-Latch)

• Output Discharge Function (Disable Option)

• Integrated Boot Strap MOSFET Switch

• QFN-32 (RTV/RSN) Package

APPLICATIONS

• Notebook Computer System and I/O Bus

• Point of Load in LCD TV, MFP

DESCRIPTION

The TPS51220A is a dual synchronous buck regulator controller with two LDOs. It is optimized for 5-V/3.3-V

system controller, enabling designers to cost effectively complete 2-cell to 4-cell notebook system power supply.

The TPS51220A supports high efficiency, fast transient response, and 99% duty cycle operation. It supports

supply input voltage ranging from 4.5 V to 32 V, and output voltages from 1 V to 12 V. Two types of control

schemes can be chosen depending on the application. Peak current mode supports stability operation with lower

ESR capacitor and output accuracy. The D-CAP mode supports fast transient response. The high duty (99%)

operation and the wide input/output voltage range supports flexible design for small mobile PCs and a wide

variety of other applications. The fixed frequency can be adjusted from 200 kHz to 1 MHz by a resistor, and each

channel runs 180° out-of-phase. The TPS51220A can also synchronize to the external clock, and the interleaving

ratio can be adjusted by its duty. The TPS51220A is available in the 32-pin 5×5/4×4 QFN package and is

specified from –40°C to 85°C.