MAX756 accepts a positive input voltage down to 0.7V and converts it to a higher pin selectable output voltage of 5V (or 3.3V). Typical full-load efficiency for the this IC is greater than 87%. Max756 combine a switch-mode regulator with an N-channel MOSFET, precision voltage reference, and power-fail detector in a single monolithic device. The MOSFET is a “sense-FET” type for best efficiency, and has a very low gate threshold voltage to ensure start-up under low-battery voltage conditions (1.1V typ).
The circuit can be easily wired on a very small rectangular common PCB.All connections should be kept as short as possible. If available,try to add a good quality 8 pin DIP socket for IC1. Note that the power inductor’s (L1) DC resistance significantly affects efficiency. For highest efficiency, limit L1’s DC resistance to 0.03 Ohm or less. A thru-hole type standard power inductor can be used. Similarly, the ESR of all capacitors (bypass and filter) affects circuit efficiency. Best performance is obtained by using specialized low-ESR capacitors.