The TPS51427 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 TPS51427 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. R_DS(on) current sensing methods offers maximum cost saving.

The TPS51427 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.