20A 300W step-down buck converter constant voltage constant current synchronous rectification power supply module 


Synchronous rectification is a new technology that uses a dedicated power MOSFET with extremely low on-resistance to replace the rectifier diode to reduce the rectification loss.
It can greatly improve the efficiency of the DC/DC converter and there is no dead zone voltage caused by the Schottky barrier voltage. 
The power MOSFET is a voltage-controlled device, and its volt-ampere characteristic is linear when it is turned on. 
When using a power MOSFET as a rectifier, the gate voltage must be synchronized with the phase of the rectified voltage to complete the rectification function, so it is called synchronous rectification. 
Synchronous rectification technology greatly reduces the rectification loss at the output end of the switching power supply, thereby improving the conversion efficiency and reducing the heat of the power supply itself.


Module parameters
Module properties: Synchronous rectification non-isolated step-down constant current constant voltage module CC CV charging module


Application: high-power LED constant current drive, lithium battery charging (including ferroelectric), 4V, 6V, 12V, 14V, 24V battery charging, Ni-Cd Ni-MH battery (battery pack) charging, solar panels, wind turbines


Input voltage: 6-40VDC
Output voltage: Continuously adjustable (1.2-35VDC) below 32V for long periods of time (for applications where input voltage is higher than output voltage and cannot be boosted)


Output current: Maximum 20A, long term within 15A (If the power tube temperature exceeds 65 degrees, please add a fan for cooling, and if the high voltage output is used, please reduce the rating)


Current limiting range: 0.2-20A (adjustment) If the module temperature exceeds 65 degrees, please add a fan.


Low dropout voltage: 3V
Working frequency: 150KHZ


Conversion efficiency: about 96% Efficiency is related to pressure difference and use environment


Output ripple:  Ripple about 50mV (excluding noise) 20M bandwidth (for reference only) Input 24V measured


Working temperature: -10? to +75?) (Please pay attention to the temperature of the power tube in actual use. If the temperature is too high, please increase the heat dissipation or use it at a reduced rating)


Potentiometer adjustment direction: clockwise (increase), counterclockwise (decrease) 


Output short circuit protection: Yes (instantaneous protection) constant current (the current constant current value cannot be short-circuited for a long time)


Input reverse connection protection: None,


Output reverse current protection: None, for loads with their own power or inductive loads, an external diode is required!


Wiring method: Terminal block
Module size: 60*53*30MM


Output current regulation method:
1. Adjust the CV potentiometer and set the output voltage to the voltage value you need according to your load requirements.
2. Set the CC potentiometer counterclockwise for about 30 turns (that is, set the output current to a minimum), connect the LED, and adjust the CC potentiometer to the current you need. 
For battery charging, discharge the battery, connect it to the output, and adjust CC to the current you need. (When used for charging, you must use a discharged battery to adjust it accurately, because the more power left in the battery, the smaller the charging current.)