The TPS51124 is a dual, adaptive on-time D-CAP™ mode synchronous buck controller. The part enables system designers to cost-effectively complete the suite of notebook power bus regulators with the absolute lowest external component count and lowest standby consumption. The fixed frequency emulated adaptive on-time control supports seamless operation between PWM mode at heavy load condition and reduced frequency operation at light load for high efficiency down to milli-ampere range. The main control loop for the TPS51124 uses D-CAP mode that is optimized for low-ESR output capacitors such as POSCAP or SP-CAP promises fast transient response with no external compensation. Simple and separate power-good signals for each channel allow flexibility of power sequencing. The part provides a convenient and efficient operation with supply input voltages (V5IN, V5FILT) ranging from 4.5 V to 5.5 V, conversion voltages (drain voltage for the synchronous high-side MOSFET) from 3 V to 28 V, and output voltages from 0.76 V to 5.5 V.

The HPA178 (TPS51124EVM) evaluation module is a high efficiency, dual synchronous buck converter providing 1.05 V at 10 A and 1.5 V at 10 A from 5-V to 25-V input. This user’s guide describes the HPA178 performance in medium switching frequency.