MC78PC00_05 Datasheet, PDF (12/16 Pages) ON Semiconductor – Low Noise 150 mA Low Drop Out (LDO) Linear Voltage Regulator

MC78PC00 Series
APPLICATION HINTS
When using these circuits, please be sure to observe the
following points:
• Phase compensation is made for securing stable operation
even if the load current varies. For this reason, be sure to
use a capacitor C_OUT with good frequency characteristics
and ESR (Equivalent Series Resistance) as described in
the graphs on page 11.
On page 11, the relations between I_OUT (Output Current)
and ESR of Output Capacitor are shown. The conditions
where the white noise level is under 40 mV (Avg.) are
marked by the shaded area in the graph. (note: When
additional ceramic capacitors are connected to the Output
Pin with Output capacitor for phase compensation, there
is a possibility that the operation will be unstable. Because
of this, test these circuits with as same external
components as ones to be used on the PCB).
1
V_IN
4.0 V
CERAMIC
CAPACITOR
1.0 mF
3 CE
2 GND
5
V_OUT
CERAMIC
CAPACITOR
ESR
I_OUT
S.A.
SPECTRUM
ANALYSER
MEASURING CONDITIONS: (1) FREQUENCY RANGE: 10 Hz TO 1.0 MHz
MEASURING CONDITIONS: (2) TEMPERATURE: 25°C
Figure 46. Measuring Circuit for White Noise: MC78PC30
• Please be sure the V_in and GND lines are sufficiently
wide. When the impedance of these lines is high, there is
a chance to pick up noise or to malfunction.
• Connect the capacitor with a capacitance of 1.0 mF or
more between V_in and GND as close as possible to V_in or
GND.
• Set external components, especially the Output Capacitor,
as close as possible to the circuit, and make the wiring as
short as possible.
IN
+
CAP.
CE
MC78PCxx
OUT
V_IN
V_OUT
+
GND
CAP.
Figure 47. Typical Application
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