DESCRIPTION The TPS51225/B/C is a cost-effective, dual-synchronous 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, D-CAP™ control provides convenient and efficient operation. The device operates with supply input voltage ranging from 5.5 V to 24 V and supports output voltages of 5.0 V and 3.3 V. The TPS51225/B/C is available in a 20-pin, 3 mm × 3 mm, QFN package and is specified from –40°C to 85°C. FEATURES • Input Voltage Range: 5.5 V to 24 V • 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 • Power Good Indicator • OVP/UVP/OCP Protection • Non-latch UVLO/OTP Protection • 20-Pin, 3 mm × 3 mm, QFN (RUK) APPLICATIONS • Notebook Computers • Netbook, Tablet Computers