LT3999EMSE#PBF

Due to market price fluctuations, if you need to purchase or consult the price. You can contact us or emial to us:   sales@allicdata.com

The LT3999EMSE#PBF voltage regulator is a high efficiency, synchronous step-down switching regulator with internal power switches. It can easily be configured to deliver up to 5A (VIN=24V, VOUT=3.3V) of output current or can be used as a drop-in replacement for traditional low-dropout linear regulators. This regulator input voltage range is 4.5V to 28V, making it suitable for a variety of applications such as industrial, automotive, and consumer applications.

Application Field

The LT3999EMSE#PBF is well suited for various applications, providing high efficiency at load currents spanning from no or light load operation to full-load operation, like computing, communications, industrial, automotive, online servers, gaming consoles, DSL/cable modems, automotive accessory power supplies, point of load converters, etc. It also provides excellent protection against over temperature condition and input under voltage lockout.

Working Principle

The LT3999EMSE#PBF employs current mode control to provide excellent transient response while operating in either continuous or discontinuous conduction mode. When operated in the continuous conduction mode, the LT3999EMSE#PBF offers an internally set output voltage setting of 0.8V to 6V. The voltage setting is programmable with external resistor for up to a 0.1% accuracy. The LT3999EMSE#PBF also allows for a freely tuned output voltage if used in the discontinuous conduction mode.when operated in discontinuous mode, the LT3999EMSE#PBF output voltage is programmable from 0.8V to 5V. The internal gate drivers are designed to easily drive the external p-channel MOSFETs which are connected on the input and the output of the IC.

The LT3999EMSE#PBF includes an integrated soft-start circuit which is monitored by a high accuracy current sense amplifier. The voltage on the VSS pin is compared to an internal 0.1V reference voltage and an internal ramp generator is used to initiate the start-up sequence. During the start-up cycle, the duty cycle is gradually increased to reach the target value defined by Rtune. The soft start time is adjustable via an external capacitor.

Once the IC reaches a fixed maximum duty cycle of around 0.95, the current sensing threshold is reached and the internal switch is turned on to lock the current variation. The cycle-by-cycle current limiting loop is active during heavy loading, making the LT3999EMSE#PBF an ideal choice for microprocessor applications with large load transients. Over current protection (OCP) is provided for additional protection against any fail-safe operation.

The LT3999EMSE#PBF also includes internal switching frequency control for improved efficiency at different loads. In addition, a power good output pin is included to inform the user when the regulator is in regulation.The LT3999EMSE#PBF is AEC-Q100 qualified, making it suitable for high temperature, mission critical, automotive applications.

The specific data is subject to PDF, and the above content is for reference