Demonstration circuit 663 is a 2-phase dual synchronous high efficiency step-down DC/DC converter with 2.7V to 8V input range. It has two outputs: 2.5V (5A MAX at 5V input) and 1.8V (5A MAX at 5V input). The demo board features the LTC®3736EUF controller. The constant frequency current mode architecture with MOSFET VDS sensing eliminates the need for sense resistors and improves efficiency. Out of phase operation significantly reduces peak input ripple current; thereby reducing the noise and input capacitor size. Switching frequency is internally set at 550kHz. For noise sensitive applications, the converter can be externally synchronized from 250kHz to 850kHz. The frequency can also be selected with PLLLPF pin. Tying PLLLPF pin to GND selects 300kHz operation; tying PLLLPF pin to VIN selects 750kHz operation. The demo circuit has output tracking, allowing VOUT2 to track VOUT1 during start-up.