1FEATURES
2• Ideal for Conversion From 1.8V or 1.5V Inputs
• Designed for use with low ESR Ceramic
Capacitors
• 0.8V, 1.2V and 1.5V Standard Voltages
Available
• Ultra Low Dropout Voltage (210mV at 3A typ)
• 1.5% Initial Output Accuracy
• Load Regulation of 0.1%/A (Typical)
• 30nA Quiescent Current in Shutdown (Typical)
• Low Ground Pin Current at all Loads
• Over Temperature/Over Current Protection
• Available in 5 Lead TO-220 and DDPAK/TO-263
Packages
• −40°C to +125°C Junction Temperature Range

APPLICATIONS
• ASIC Power Supplies In:
– Desktops, Notebooks, and Graphics Cards,
Servers
– Gaming Set Top Boxes, Printers and
Copiers
• Server Core and I/O Supplies
• DSP and FPGA Power Supplies
• SMPS Post-Regulator

DESCRIPTION
The LP38843 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 architecture 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 DDPAK/TO-263 packages.
Dropout Voltage: 210 mV (typ) at 3A load current.
Quiescent Current: 30 mA (typ) at full load.
Shutdown Current: 30 nA (typ) when S/D pin is low.
Precision Output Voltage: 1.5% room temperature
accuracy.