LP3891  Product Folder

The LP3891 is a high current, fast response regulator which can maintain output voltage regulation with minimum input to output voltage drop. Fabricated on a CMOS process, the device operates from two input voltages: Vbias provides voltage to drive the gate of the N-MOS power transistor, while Vin is the input voltage which supplies power to the load. The use of an external bias rail allows the part to operate from ultra low Vin voltages. Unlike bipolar regulators, the CMOS architectutre consumes extremely low quiescent current at any output load current. The use of an N-MOS power transistor results in wide bandwidth, yet minimum external capacitance is required to maintain loop stability.

The fast transient response of these devices makes them suitable for use in powering DSP, Microcontroller Core voltages and Switch Mode Power Supply post regulators. The parts are available in TO-220 and TO-263 packages.

Dropout Voltage: 100 mV (typ) @ 0.8A load current.

Ground Pin Current: 3 mA (typ) at full load.

Shutdown Current: 60 nA (typ) when S/D pin is low.

Precision Output Voltage: 1.5% room temperature accuracy.

• Ultra low dropout voltage (100mV @ 0.8A typ)
• Low ground pin current
• Load regulation of 0.04%/A
• 60 nA typical quiescent current in shutdown
• 1.5% output accuracy (25°C)
• TO-220, TO-263 packages
• Over temperature/over current protection
• -40°C to +125°C junction temperature range

• DSP Power Supplies
• Server Core and I/O Supplies
• PC Add-in-Cards
• Local Regulators in Set-Top Boxes
• Microcontroller Power Supplies
• High Efficiency Power Supplies
• SMPS Post-Regulators