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.