With a minimum input voltage of 1.65V, the LP3991 LDO provides a fixed and stable output voltage for load currents up to 300 mA. The device is suitable for use where an accurate low voltage is required from a low input voltage source and is therefore suitable for post regulation of switching mode regulators. In such applications, significant improvements in performance and EMI can be achieved with little loss of overall efficiency.
Typical application circuit
The LP3991 offers a fixed output as low as 1.2V from a wide input range of 1.65V to 4v. Using the Enable (EN) pin, the device can be controlled to provide an off state in which a negligible amount of supply current is drawn out. The LP3991 is designed to be a stable space-saving ceramic capacitor, down to 0402 case size. Performance is specified in the junction temperature range from -40°C to +125°C.
The LP3991 device is a monolithic low voltage drop regulator with a low input operating voltage tolerance. The device incorporates critical protection circuits, including output current limiting and thermal shutdown. Using the EN pin, the device can be controlled to provide an off state in which negligible supply current is drawn. The LP3991 is designed to be a stable space-saving ceramic capacitor, down to 0402 case size.
Functional block diagram
