PMIC - Voltage Regulators - DC DC Switching Controllers

The LTC3874IUFD#PBF is a high performance dual-channel non-synchronous buck controller with an integrated MOSFET driver. It is ideal for power supplies and voltage converters that require high efficiency, fast transient response and low output ripple along with a wide range of operating frequencies. It supports peak current mode control, constant frequency, and both sync and non-sync modes.

The LTC3874IUFD#PBF utilizes a state-of-the-art MOSFET driver to efficiently drive two non-synchronous buck switches. It also includes programmable overcurrent protection and built-in compensation to ensure safe, reliable operation. The controller also supports a wide range of operating frequencies, allowing designers to optimize power efficiency and response time.

Working Principles

The LTC3874IUFD#PBF is based on a peak current-mode control architecture. The controller senses the peak current through an external sense resistor connected between the output of the controller and ground. A voltage ramp is generated by a linear current ramp using this external resistor. The ramp is then compared with the voltage applied to the feedback pin (FB) of the controller. The output from this comparison is used to adjust the switching frequency to maintain a constant output voltage.

The controller uses a combination of a clock and an internal oscillator to generate a switching frequency. The clock controls the frequency of the internal oscillator, thus allowing the switching frequency to be adjusted. The controller supports both sync and non-sync modes and the switching frequency can be adjusted from 0 Hz to 16kHz.

Protection Features

The LTC3874IUFD#PBF includes a number of protection features such as overcurrent protection, overvoltage protection and undervoltage lockout. The integrated MOSFET driver includes an overcurrent protection circuit to reduce the effects of switching transients. An adjustable overvoltage protection circuit is also included to protect against unexpected output voltage fluctuations. Finally, an undervoltage lockout feature is provided to avoid device damage due to prolonged input voltage sag.

Applications

The LTC3874IUFD#PBF is particularly well-suited for use in a wide range of power supply and voltage converter applications, specifically those requiring high efficiency, fast transient response and low output ripple. This includes applications such as notebook and tablet PCs, LCD TVs, and white goods.