advertisement Very Low Dropout (VLDO) Linear Regulators Supply
Low Voltage Outputs
Design Note 292
Tom Gross
Introduction
With each new generation of computing systems, total
power continues to increase while system voltages
fall. CPU core voltages and logic supplies below 1.8V
are now commonplace. Power supplies must not only
regulate low output voltages but they must also operate
from low input voltages. A low voltage, low dropout
linear regulator is an attractive conversion option for
applications where output currents are in the several
ampere range. Component count and cost are low in
comparison to switching regulator solutions, and with
low input-to-output voltage differentials, efficiencies
are comparable. MOSFET controller/driver are devices well suited to
deliver lower output voltages from a supply of 1.8V
or lower. Each device offers excellent line/load regulation, temperature performance and transient load
step response.
Figure 1 illustrates the LT1580 delivering 1.3V at 3A
(maximum), from a 1.8V input supply. This particular
conп¬Ѓguration requires a higher voltage supply to bias …