LNK6766E

The LinkSwitch-TN family of energy efficient, off-line switcher ICs are an economical choice for an AC/DC offline power supply design. The LinkSwitch-TN product group offers an array of proprietary technologies, features and protections to provide an easy-to-implement design solution to meet many off-line applications. One of these products is the LNK6766E. The LNK6766E has wide input voltage and high frequency range which enables the use of small size inductors and capacitors. This product combines several features and protections within one IC.

Application Fields of the LNK6766E

The LNK6766E is suitable for a variety of off line SMPS applications such as isolated or non-isolated adapters and chargers. The high frequency and wide input voltage range permits easy implementation of a very small and cost effective solution for 5V and 12V chargers. The LNK6766E also has the capability of providing regulated output in the presence of a wide output capacitive load range.

Working Principle of the LNK6766E

The LNK6766E operates in Discontinuous Conduction Mode (DCM) but can change to other modes such as Continuous Conduction Mode (CCM) and Quasi-Resonant (QR) mode. It is a fixed frequency switcher and operates in the range of 100 kHz to 1.2 MHz.

The LNK6766E is a current mode controller. The output is regulated by sensing a small amount of output current and comparing it with an internally generated reference current. Everytime the output current is higher than the internal reference current, the duty cycle of the switch is decreased and vice versa. This process continues until the desired output is achieved.

The LNK6766E also provides various protection functions such as Over Voltage, Over temperature and Under Voltage lockouts. It also provides Over Current protection by detecting the secondary current through its sense pins and then shutting off the power switch for a predetermined time.

Conclusion

The LNK6766E is an excellent choice for low cost off-line SMPS applications. It offers a wide input voltage range and high frequency operation that allows for the use of smaller components. It also provides several protection functions that ensure safe and reliable operation.