Here's a synchronous, current-mode, step-down dc-dc controller with differential output voltage sensing. Using a pair of VSENSE inputs like this enables high-accuracy regulation in high-current applications.
Linear Technology's LTC3823 can either sense the voltage drop across the synchronous power MOSFET, or where control of maximum output current is important, it can be used with a sense resistor in series with the source of the lower MOSFET. It has a 4.5- to 30-V input-voltage range and can develop output voltages from 0.6 V to 90% of the input voltage (or 0.6 to 3.3 V with remote sensing).
Output voltage accuracy is ±0.5% at room temperature and ±0.67% from 0°C to 85°C. Tracking and sequencing functions allow the controller to power-up and power-down multiple power supplies. In addition, the LTC3823 can be configured for phase-locked-loop frequency synchronization.
Pricing in quantities of 1000 units starts at $2.75.