r1120n RICOH Co.,Ltd., r1120n Datasheet - Page 21

• Manufacturer Part Number: r1120n
• Description: Low Noise 150ma L.d.o Regulator
• Manufacturer: RICOH Co.,Ltd.

18
R1120N
When using these ICs, be sure to take care of following points :
• In these ICs, phase compensation is made for securing stable operation even if the load current is varied.
• Make V
• Connect the capacitor with a capacitance of 1
• Set external components, especially Output Capacitor, as close as possible to the ICs and make wiring
For this purpose, be sure to use a capacitor C
Series Resistance) of which is in the range described as follows :
The relations between I
conditions when the white noise level is under 40
(note : When the additional ceramic capacitors are connected to the Output Pin with Output capacitor for
phase compensation, there are possibilities that the operation will be unstable. Because of this, test these
ICs with as same external components as ones to be used on the PCB.)
not to work correctly.
shortest.
< measuring conditions >
100
100
DD
0.1
0.1
10
10
1
1
0
and GND line sufficient. When the impedance of these is high, there is a case to pick up the noise or
0
V
Freqency band : 10Hz to 1MHz
IN
=4V
Ceramic Capacitor 4.7 F
Ceramic Capacitor 10 F
Output Current I
Output Current I
50
50
OUT
OUT
OUT
(Output Current) and ESR of Output Capacitor are shown below. The
80
80
(mA)
(mA)
APPLICATION HINTS
150
150
µ
OUT
F or more between V
with good frequency characteristics and ESR (Equivalent
µ
V
V (Avg.) are marked as the hatched area in the graph.
IN
• Measuring Circuit for white noise ; R1120N301B
Ceramic
Capacitor1 F
Temperature : 25˚C
100
4
3
0.1
10
1
CE
V
DD
R1120N301B
0
IN
and GND as close as possible.
GND
Ceramic Capacitor 6.8 F
2
V
Output Current I
OUT
50
1
Ceramic
Capacitor
OUT
ESR
80
(mA)
I
OUT
150
S.A.
Spectrum
Analyzer