Pololu 5V Step-Up Voltage Regulator NCP1402 is based on the NCP1402 boost regulator IC. Its small dimension of just 8.4 mm × 12.7 mm and a startup voltage of down to 0.8 V make it easy to build 5V circuits that are powered by lower battery voltages. The available output current and output voltage ripple depend on the input voltage, but the regulator can provide up to 200 mA if the input voltage is high enough.
With low input voltages, the output voltage ripple is under 40 mV peak-to-peak. When the input voltage is close to the output, the output ripple quickly climbs to 150 mV peak-to-peak. Therefore, adding capacitance from the output to ground is recommended for noise-sensitive applications with input voltages close to the output voltage.
Some example applications include:
Pololu Web Site: https://www.pololu.com/product/798