The TPS51427A is a dual synchronous step-down controller designed for notebook and mobile communications applications. This device is part of a low-cost suite of notebook power bus regulators that enables system designs with low external component counts. The TPS51427A includes two pulse-width-modulation (PWM) controllers, SMPS1 and SMPS2. The output of SMPS1 can be adjusted from 0.7 V to 5.9 V, while the output of SMPS2 can be adjusted from 0.5 V to 2.5 V. This device also features a low-dropout (LDO) regulator that provides a 5-V/3.3-V output, or adjustable from 0.7-V to 4.5-V output via LDOREFIN. The fixed-frequency emulated adaptive on-time control supports seamless operation between PWM mode under heavy load conditions and reduced frequency operation at light loads for high-efficiency down to the milliampere range. An integrated boost switch enhances the high-side MOSFET to further improve efficiency. The main control loop is the D-CAP™ mode that is optimized for low equivalent series resistance (ESR) output capacitors such as POSCAP or SP-CAP. Advanced ramp compensation minimizes jitter without degrading line and load regulation. RDS(on) current sensing methods offers maximum cost saving.

The TPS51427A supports supply input voltages that range from 5.5 V to 28 V. It is available in the 32-pin, 5-mm × 5-mm QFN package (Green, RoHs- compliant, and Pb-free). The device is specified from -40°C to +85°C.

• Fixed-Frequency Emulated On-Time Control; Frequency Selectable from Three Options
• D-CAP™ Mode Enables Fast Transient Response Less than 100 ns
• Advanced Ramp Compensation Allows Low Output Ripple with Minimal Jitter
• Selectable PWM-Only/OOA™/Auto-Skip Modes
• Wide Input Voltage Range: 5.5 V to 28 V
• Dual Fixed or Adjustable SMPS:
  • 0.7 V to 5.9 V (Channel1)
  • 0.5 V to 2.5 V (Channel2)
• Fixed 3.3-V/5-V, or Adjustable Output 0.7-V to 4.5-V LDO; Capable of Sourcing 100 mA
• Fixed 3.3-VREF Output Capable of Sourcing 10 mA
• Temperature Compensated Low-Side RDS(on) Current Sensing
• Adaptive Gate Drivers with Integrated Boost Switch
• Bootstrap Charge Auto Refresh
• Integrated Soft Start, Tracking Soft Stop
• Independent PGOOD and EN for Each Channel
• OOB Function Disabled. Refer to TPS51427 for OOB-Enabled Device
• APPLICATIONS
  • Notebook I/O and System Bus Rails
  • Graphics Application
  • PDAs and Mobile Communication Devices

D-CAP, OOA are trademarks of Texas Instruments. All other trademarks are the property of their respective owners.