Features of using IC LNK304 chip in PSU

Features of using IC LNK304 chip in PSU Link Switch-TN chips are used in power supplies without galvanic isolation. These chips have successfully found a replacement for linear voltage regulators with a network input and a network power supply with capacitive ballast. Here are some features of these devices: smallest piping of the components in the converter circuits; soft start; operation at 66 kHz; the exact limit of output current; built-in modulation of oscillation frequency; minor consumption; ability to work without a load. Chips are available in the following housings: DIP8 and SMD8. To increase the electrical strength the housing has seven outputs. The structure of the chip has an N-channel MOS transistor and a controller for this transistor. Let's have a look at the operation of the converter, assembled according to the scheme of a buck regulator where LNK304 chip is used as a key. This converter can be used to power home appliances, LED devices, LCD indicators, electricity meters and other devices that do not require galvanic isolation from the network. The input circuit - RF1 resistor, D3, D4 rectifier diodes, C4, C5 capacitances and L2 throttle. L1 throttle provides a continuous mode of operation for the converter. During every period of the operation the current flowing through the throttle is not interrupted. Feedback voltage is removed from L1 throttle, rectified by D2 diode, smoothed by C3 filter and transferred to FB output of the chip via R1R3 divider.