and Product name: adjustable step-down module Product size: 6.5x3.8cm (length x width) Weight: 23G (including packaging) color: blue Packaging: 1PC Module highlights: 1. With a voltmeter display, the voltmeter error is 0.1V, and the range is 4-40V. (Note: If the input voltage is below 4V, the onboard voltmeter will not work and will not display.) 2. With a large volume of 5 x 5, lightly touch the button to switch between measuring the input or output voltage, and an indicator light will display which terminal voltage is being measured. The default display for the first startup is the input voltage on the digital tube, and the input indicator light IN is on; Gently touch the button, the digital tube will display the output voltage, and the output indicator light OUT will be on. And maintain the setting, even if it is powered off and then turned on again 3. The voltmeter can be turned off. Press and hold the switch for more than 1 second and less than 4 seconds, and then release to turn it off. After the voltmeter is turned off, simply press the switch briefly to turn on the voltmeter. 4. Input and output voltage measurement error calibration function. Press and hold the switch for more than 4 seconds, and after releasing, the voltage measurement error calibration function will enter. At this time, the IN light will be on (calibration input end), and the digital tube will flash to display a positive value (factory parameter is 0.0). At this time, short press the button to change this value (value range is -0.5-0.5, unit is V). A positive number represents upward calibration, and a negative number represents downward calibration. After adjusting the calibration value of the input end, press and hold the button for more than 2 seconds. After releasing, enter the error calibration of the output end. At this time, the OUT light will be on (calibrate the output end) and the calibration value of the output end will be displayed. The adjustment method is the same as that of the input end. After adjusting the calibration value of the output end, press and hold the button for more than 2 seconds. After releasing, save the set value and return to the normal display voltage. The set calibration value will take effect immediately and will not be lost upon power failure. With this feature, you can meet your higher accuracy requirements. 5. With wiring terminals, it can be easily used without soldering iron, and the welding wire connection points should be retained (the input voltage must be more than 1v higher than the output voltage). 6. The output current can reach up to 3A, and it is recommended to operate at around 2A. If it exceeds 2A, add a heat sink. 7. Adopting an internal oscillation frequency of 150KHz, it belongs to the second generation switch voltage regulator, with low power consumption and high efficiency. 8. With reverse connection protection, reverse connection does not burn. 9. Equipped with overheating protection and short circuit protection functions Input voltage: 2.5V-40V Output voltage: 1.25V-37V (adjustable) Output current: 3A Conversion efficiency: 92% Output ripple:<30mV Switching frequency: 150KHz Working temperature: -45 ℃-and85 ℃ Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.