TPS51221
www.ti.com. SLVS786A – NOVEMBER 2007 – REVISED MARCH 2009 Fixed Frequency, 99% Duty Cycle Peak Current Mode
Notebook System Power Controller
FEATURES APPLICATIONS 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-Audioв„ў Skip) Programmable Droop Compensation Voltage Servo Adjustable Soft Start 200 kHz to 1 MHz Fixed Frequency PWM Current Mode Architecture 180В° 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) 1 2 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 180В° out
of phase. The TPS51221 can also synchronize to the
external clock, and the interleaving ratio can be …
