Voltage regulators – Velleman DCA75 User Manual
Page 28

Atlas DCA Pro User Guide
December 2012 – Rev 1
Page 28
Voltage Regulator
Red-IN Green-OUT
Blue-GND
VOUT=5.024V
IQ=2.54mA
VDO=1.83V
Voltage Regulators
Voltage regulators are available in many different types and
different packages.
The DCA Pro is able to identify many types of regulator,
typically regulators with outputs less than 8V, depending on
current requirements.
When a regulator is identified, its
pinout, output voltage, quiescent current
consumption and drop-out voltage are
displayed.
Negative voltage regulators (such as
the popular 79L05) will be shown with
a negative V
OUT
figure.
The displayed drop-out voltage (V
DO
) is the voltage that is required
between input and output of the regulator to enable voltage regulation
to take place. Common regulators have a drop-out voltage of around
2V. Many “Low drop-out” regulators may have a drop-out voltage of
0.5V or less. The DCA Pro measures drop-out at very low load
currents on the regulator’s output (typically less than 1mA). The drop-
out voltage of a regulator increases significantly with load current.
Some voltage regulators are not stable when used outside of their
intended circuitry (decoupling capacitors, proper loads etc). The
DCA Pro may not be able to identify the regulator correctly if it is not
stable during analysis.