What is the role of the control in the on-board DCDC?(1)

For the 110 v input power supply products with TRIM or ADJ (adjustable) output pins, the output voltage can be adjusted within a certain range through resistors or potentiometers, control in the on-board DCDC and the general adjustment range is ±10%.

For the TRIM output pin, the center of the output potentiometer and the center TRIM are all connected to +S, -S in the pin module, and the other two ends are connected to +S, -S respectively. There is no +S, and the -S ends receive the positive and negative outputs of the corresponding main circuit respectively (+S is connected to +Vin, -S is connected to -Vin), and then adjust the potentiometer. The resistance of the potentiometer is generally 5~10kΩ.

input protection circuit
General module power products have built-in filters, which can meet the requirements of general power supply applications. If a more demanding power system is required, an input filter network should be added. An LC or π-type network can be used, but care should be taken to choose a smaller inductance and larger capacitance as much as possible.
In order to prevent the transient high voltage of the input power supply from damaging the power supply of the module, it is recommended that the user connect a transient absorption diode at the input end and use it with a fuse to ensure that the module is within a safe input voltage range. In order to reduce common-mode noise, Y (Cy) capacitors can be added, and a few nf high-frequency capacitors are generally selected. R is a fuse, D1 is a protection diode, and D2 is a transient absorption diode (P6KE series).

control in the on-board DCDC The ADJ output pins are divided into input adjustment and output adjustment. Output trim and output trim. The adjustment method of the TRIM pin is the same. When one end of the potentiometer is connected to the center, the output voltage can only increase the output voltage, and the other end is connected to the ground of the input.