More and more, battery operated systems are requiring lower terminal voltages to power internal circuits. Multi-cell designs are rapidly migrating to single-cell architectures to reduce system cost. A prime example of this system type is digital cameras, which often use a single-cell 3.6V Li-Ion battery for their power source. Digital cameras contain high-speed memory ICs, which require tight voltage regulation at moderate loads to meet the required timing parameters of the system. Precision low dropout (LDO) regulator devices can be used to meet these requirements but in doing so, the LDO regulators must be able to successfully operate in the ‘dropout’ mode as the battery discharges. Dropout mode is entered when the input voltage (from the battery source) is equal to the “nominal output voltage” of the LDO; for example a 3.3V LDO enters dropout mode when its input voltage at the V IN pin is equal to 3.3V. Minimal output voltage droop and minimal LDO power dissipation are critical to meeting various system performance parameters and extending the life of the battery. AN776 DC Performance Comparisons of CMOS vs. Bipolar LDOs when Operating in "Dropout" (VIN = Nominal VOUT) Mode Author: Patrick Maresca, BACKGROUND INFORMATION: Microchip Technology, Inc. CMOS vs. BIPOLAR ARCHITECTURE Figures 1A and 1B compare the block diagram for a common bipolar regulator with that of an equivalent regulator fabricated in INTRODUCTION ……