DC/DC Controller Delivers 97% Efficiency

With an efficiency as high as 97%, the LTC1778 current-mode, synchronous step-down dc/dc controller uses a valley current control architecture to deliver low duty cycles with less than 100 ns of on time without the need for a sense resistor. The controller has an input-voltage range from 4V to 36V and an output range from 0.8V to 90% of the input voltage.
Operating frequencies up to 2 MHz are possible, determined by a MOSFET. The controller also includes a ±1% accurate 0.8V voltage reference and protection against overvoltage, latch-off, and output short circuit. Other features include true current-mode control, stable operation with ceramic output capacitors, a 2% to 90% duty cycle at 200 kHz, dual N-channel MOSFET synchronous drive, and a power-good output monitor. In a 16-pin SSOP, price is $2.70 each/1,000.