Features: 100% brand new and high quality. This is a DC-DC boost converter module with working frequency of 1 MHz. The module has high efficiency up to 94%, usually can be 84%~91%. Ultra small size and light weight, it is convenient to use. Widely used for battery-powered devices, multimeter, small power motors, cameras, electric toys, model aircraft, LED lighting, electronic DIY kits, etc. Specification: Output voltage: 3.7V, 5V, 12V (Optional) Efficiency: 94% (usually is 84%-91%) Quiescent current: 0.19mA Operating temperature range : -40~+85 Degrees Celsius Storage temperature range : -65~+150 Degrees Celsius Size: 13*11*5.2mm / 0.5*0.4*0.2in Weight: 2g / 0.1oz (approx.) Protection : Over current protection(OCP) Over voltage protection(OVP) Short circuit protection(SCP) Over temperature protection(OTP) Pin description: Vi : Input positive(+) GND : Input and Output negative(GND/-) Vo : Output positive(+) Output 3.7V : Input voltage: DC 2.6 - 3.6V output voltage: DC 3.7V3% Maximum output : 3.7V/1200MA(See the table below for details) Output 5V : Input voltage: DC 2.6 ~ 4.5V Output voltage: DC 5V3% Maximum output : 5V/1200MA Output 12V : Input voltage: DC 2.6 ~ 6V Output voltage: DC 12V3% Maximum output : 12V/500MA Package list: 1 * Module Note: This is a DC - DC voltage converter module, please pay attention when using: 1, The input voltage should not be higher than maximum input range. 2, The output power cannot be higher than the maximum load for a long time. 3, The input power must be higher than output power, because of the power consumption of the module itself. FAQ: Q: Why the output voltage is lower than the nominal voltage? A :Because the input power is too low.Use a multimeter to test the input voltage, the input voltage is very low at this time.