LNK457VG

LNK457VG can be categorized as a PMIC (Power Management IC) - LED Driver. It is a constant current regulator, which has the purpose of controlling the current flowing through an LED circuit. It is specifically designed for use in LED backlighting applications and portable device designs.

LNK457VG\'s main feature is its ability to detect LED faults and its ability to transmit LED current as close to the designed value as possible. This is achieved by its internal current sense resistor, error amplifier, reference voltage and over-temperature protection functions. It is also capable of pre-programming the LED current during the motor-start or after-stop period.

The current regulator part of the LNK457VG has many functions such as a peak current limiting, current distribution across LEDs, open and shorted LED protection, over-temperature protection, and inrush limiting. The functions of the regulator are enabled or disabled using a selectable logic input.

The peak current limiting function helps to protect the LEDs from over-current. It is also used to control the current within the linear range of an LED by limiting the peak current. This is done by monitoring the voltage at the sense node of the current sense resistor. The current distribution across LEDs helps to ensure that the current in a multiple LED circuit is balanced, hence preventing one LED from drawing more current than the rest.

The open and shorted LED protection functions help to detect any open or shorted LED. If one of these conditions is detected, the system will either enable or disable the LED output depending on the type of LED fault detected. Over-temperature protection monitors the junction temperature of the LED, and will disable the LED if the junction temperature exceeds a certain threshold.

The inrush limiting feature helps to reduce the inrush current at start-up. This is done by monitoring the voltage across the sense resistor and comparing it to a reference voltage. The reference voltage is set using a logic input. If an excessively high current is sensed, the current regulator will disable the LED until the voltage is lowered to a safe level.

The LNK457VG provides designers with the flexibility and ease in controlling the current consumed by an LED circuit. It offers a variety of features such as peak current limit, over-temperature protection, open and shorted LED protection, current distribution, and inrush limiting. These features help to ensure that the current through an LED circuit is kept within the designed range and that any faults will be detected quickly.