LM3311SQ/NOPB

The LM3311SQ/NOPB is a switched-mode voltage regulator that is part of a larger device family, the Texas Instruments (TI) LM33x Series. This family of voltage regulators helps to provide stable and regulated voltage necessary for functional operation of DC/DC systems and digital circuits, making them suitable for use in devices such as backlighting for displays, regulators for power supplies, and power-management integrated circuits within computers and other digital devices. This device is a switch-mode regulator that employs a synchronous Buck converter to output 3.3V with a programmable current limit up to 10A and fast dynamic response to load transients over a wide input voltage ranges.

Features and Benefits

The LM3311SQ/NOPB features a wide input voltage range of 6V to 42V and comes in two package variants: a through-hole 8-pin "D" package and an 8-pin LQFN SMT package. It boasts short circuit protection, current limit protection, thermal protection, cycle-by-cycle current limit, and under voltage lockout. The device also offers a wide operating temperature range of -40°C to 125°C and is programmable from the output voltage. This device offers faster dynamic response and larger output capacitors when compared to other switch mode voltage regulators, making it idea for the power management of a wide variety of portable devices, including laptops and cell phones. Moreover, the device is resistant to reverse polarity, reverse transients, and common-mode transients.

Applications

The LM3311SQ/NOPB device is suitable for a variety of applications within power management, including backlighting for displays, voltage regulator for power supplies, and power management integrated circuits (PMICs) in computers and other digital devices. This device is also suitable for low-noise and low-emission modules and small-scale power converters.

Working Principle

The LM3311SQ/NOPB employs a synchronous Buck converter with programmable current limit of up to 10A and fast dynamic response to load transients. The device uses high-frequency switching technology to provide high conversion efficiency and excellent line and load regulation. The device contains an internal switch, configured as a Buck converter, that switches between full-on and full-off states; this switching state initiates when the device senses a voltage appropriate for the desired output voltage. The switching frequency is adjustable, allowing the user to select the desired frequency for their application. The device also contains a sense resistor to monitor current and provide protection against over-current and short-circuit conditions. Finally, the device contains an undervoltage lockout (UVLO) system, which will shut the device off to protect itself if the input voltage falls below a specified threshold.

Conclusion

The LM3311SQ/NOPB is a versatile switch-mode voltage regulator that can be used in a variety of power-management applications. The device features a wide input voltage range, short circuit protection, current limit protection, and thermal protection, making it well-suited for some of the most demanding applications. Its high-frequency switching technology provides high conversion efficiency, excellent load and line regulation, and fast dynamic response to load transients. With a wide operating temperature range and two packaging options, the LM3311SQ/NOPB is an ideal choice for a variety of power management applications.