TPS51225B

www.ti.com TPS51225, TPS51225B, TPS51225C SLUSAV0B – JANUARY 2012 – REVISED SEPTEMBER 2012 Dual Synchronous, Step-Down Controller with 5-V and 3.3-V LDOs Check for Samples: TPS51225, TPS51225B, TPS51225C FEATURES 1 APPLICATIONS 2 Input Voltage Range: 5.5 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 300kHz/355kHz Frequency Setting Auto-skip Light Load Operation (TPS51225/C) OOA Light Load Operation (TPS51225B) Internal 0.8-ms Voltage Servo Soft-Start Low-Side RDS(on) Current Sensing Scheme with 4500 ppm/°C Temperature Coefficient Built-in Output Discharge Function Separate Enable Input for Switchers (TPS51225/B/C) Dedicated OC Setting Terminals Netbook, Tablet Computers DESCRIPTION The TPS51225/B/C is a cost-effective, dualsynchronous buck controller targeted for notebook system-power supply solutions. It provides 5-V and 3.3-V LDOs and requires few external components. The 260-kHz VCLK output can be used to drive an external charge pump, generating gate drive voltage for the load switches without reducing the main converter efficiency. The TPS51225/B/C supports high efficiency, fast transient response and provides a combined power-good signal. Adaptive on-time, DCAP™ control provides convenient and efficient operation. The device operates with supply input vol...