LT1939IDD#PBF

PMIC - Voltage Regulators - Linear + Switching

The LT1939IDD#PBF is a high performance and highly efficient switching DC/DC controller and voltage regulator. It is designed to drive high-side and low-side N-Channel MOSFETs to implement a tightly regulated dc/dc converter circuit. The LT1939IDD#PBF is capable of driving external MOSFETs with gate voltage increments of 10mV for up to 8A of continuous current. The LT1939IDD#PBF is an optimized member of the LT1938 family of DC/DC controllers.

Application Field

The LT1939IDD#PBF can be used in a variety of applications such as automotive, industrial, telecom and power management. The power supply system it is used in can range from point-of-load management to isolated DC/DC converters. It is suitable for such applications as power over Ethernet, point-of-load converters, Li-Ion battery chargers and automotive applications.

Working Principle

The LT1939IDD#PBF works by using two switching MOSFETs, one high-side and one low-side connected in a synchronous rectifier configuration. Current flows through a MOSFET connected in series with the power supply, and is limited by the current sense resistance. When the current reaches the programmed level, the high-side MOSFET is turned off and the current then flows through the programmed ramp circuit. When the ramp voltage reaches the programmed level, the low-side MOSFET is then turned on and the current starts to flow in the opposite direction, until the current sense voltage reaches the programmed level. This cycle then repeats producing a regulated output voltage.

Conclusion

The LT1939IDD#PBF is a highly efficient switch DC/DC controller and voltage regulator that can be used in a variety of applications. Its unique design allows it to produce a tightly regulated output voltage in a very small package size. It is suitable for automotive, industrial, telecom and power management applications as well as point-of-load management and isolated DC/DC converters.