TPS51285A

TPS51285A TPS51285B www.ti.com SLVSBX0 – APRIL 2013 Ultra-Low Quiescent (ULQ™) Dual Synchronous Step-Down Controller with 5V and 3.3V LDOs Check for Samples: TPS51285A, TPS51285B FEATURES 1 APPLICATIONS 2 Input Voltage Range: 5 V to 24 V Notebook Computers Output Voltages: 5 V and 3.3 V (Adjustable Range ±10%) Built-in, 100-mA, 5-V and 3.3-V LDOs Clock Output for Charge-Pump ±1% Reference Accuracy Adaptive On-Time D-CAP™ Mode Control Architecture with 400 kHz (CH1) and 475 kHz (CH2) Frequency Auto-skip and ULQ™ modes for long battery life in system stand-by mode Internal 0.8-ms Voltage Servo Soft-Start Low-Side RDS(on) Current Sensing Scheme Built-In Output Discharge Function Separate Enable Input for Switchers Dedicated OC Setting Terminals Power Good Indicator OVP, UVP and OCP Protection Non-Latch UVLO and OTP Protection Tablet Computers DESCRIPTION The TPS51285A and TPS51285B are cost-effective, dual synchronous buck controllers with 5-V and 3.3-V LDOs, targeted for notebook system-power supply solutions. The device achieves low power consumption by the use of auto-skip and ULQ™ modes, which is beneficial for long battery life in system stand-by mode. The 256-kHz VCLK output is provided to drive an external charge pump, generating gate drive voltage for the load switches with minimum power consumption in the main converter. The device employs adaptive on-time DCAP™ mode control which enables fast load transient response without ext...