1FEATURES

2· Input Voltage Range: 4.5 V to 28 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

· Current Mode Architecture

· 180° Phase Shift Between Channels

· Resistor or Inductor DCR Current Sensing

· Powergood Output for each channel

· OCL/OVP/UVP/UVLO protections

· Current Monitor Output for CH1

· Thermal Shutdown (Non-latch)

· Output Discharge Function (Disable option)

· Integrated Boot Strap MOSFET Switch

· QFN32 (RTV)

APPLICATIONS

· Notebook Computer System and I/O Bus

· Point of load in LCD TV, MFP

DESCRIPTION

The TPS51221 is a dual synchronous buck regulator

controller with 2 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 TPS51221 supports high

efficiency, fast transient response and 99% duty cycle operation. It supports supply input voltage ranging

from 4.5 V to 28 V, and output voltages from 1 V to

12 V. Peak current mode supports stability operation

with lower ESR capacitor and output accuracy. The

high duty (99%) operation and 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

1MHz by a resistor, and each channel runs 180° out of phase. The TPS51221 can also synchronize to the

external clock, and the interleaving ratio can be

adjusted by its duty. The TPS51221 is available in the

32-pin 5×5 QFN package and is specified from –40°C

to 85°C.