• 3.3-V and 5-V 100-mA Bootstrapped Standby Regulators with Independent Enables
• Selectable D-CAP® Mode Enables Fast Transient Response Less than 100 ns
• Selectable Low Ripple Current Mode
• Less than 1% Internal Reference Accuracy
• Selectable PWM-only/Auto-skip Modes
• Low-side R_DS(on) Loss-less Current Sensing
• R_SENSE Accurate Current Sense Option
• Internal Soft-start and Integrated V_OUT Discharge Transistors
• Integrated 2-V Reference
• Adaptive Gate Drivers with Integrated Boost Diode
• Power Good for Each Channel with Delay Timer
• Fault Disable Mode
• Supply Input Voltage Range: 4.5 V to 28 V
• APPLICATIONS
  • Notebook Computers System Bus and I/O

D-CAP is a registered trademark of Texas Instruments.

The TPS51120 is a highly sophisticated dual current mode synchronous step-down controller. It is a full featured controller designed to run directly off a three- or four-cell Li-ion battery and provide high-power and 5-V and/or 3.3-V standby regulation for all the downstream circuitry in a notebook computer system. High current, 100-mA, 5-V or 3.3-V on-board linear regulators have glitch-free switch over function to SMPS and can be kept alive independently during standby state. The pseudo-constant frequency adaptive on-time control scheme supports full range of current mode operation including simplified loop compensation, ceramic output capacitors as well as seamless transition to reduced frequency operation at light-load condition. Optional D-CAP™ mode operation optimized for SP-CAP or POSCAP output capacitors allows further reduction of external compensation parts. Dynamic UVP supports VIN line sag without latch off by hitting 5V UVP. No negative voltage appears at output voltage node during UVLO, UVP, and OCP, OTP or loss of VIN.

The TPS51120 32-pin QFN package is specified from -40°C to 85°C ambient temperature.