R1122N_17 Datasheet, PDF (8/21 Pages) RICOH electronics devices division – LOW NOISE 150mA LDO REGULATOR

R1122N
TECHNICAL NOTES
When using these ICs, consider the following points:
Phase Compensation
In these ICs, phase compensation is made for securing stable operation even if the load current is varied. For
this purpose, be sure to use a capacitor COUT with good frequency characteristics and ESR (Equivalent Series
Resistance).
(Note: When the additional ceramic capacitors are connected to the output pin with the output capacitor for
phase compensation, the operation might be unstable. Because of this, test these ICs with the same external
components as the ones to be used on the PCB.)
Recommended Capacitors ; GRM40X5R225K6.3 (Murata)
GRM40-034X5R335K6.3 (Murata)
GRM40-034X5R475K6.3 (Murata)
PCB Layout
Make VDD and GND lines sufficient. If their impedance is high, picking up the noise or unstable operation may
result. Connect a capacitor with a capacitance of 2.2μF or more between VDD and GND pin as close as possible.
Set external components, especially output capacitor as close as possible to the ICs and make wiring as short
as possible.
TYPICAL APPLICATION
IN
+
Cap.
CE
R1122Nxx1A
VDD
Series
VOUT
GND
OUT
+
Cap.
IN
+
Cap.
CE
R1122Nxx1B
VDD
Series
VOUT
GND
OUT
+
Cap.
(External Components)
Output Capacitor ; Ceramic 2.2μF (Set output voltage in the range from 2.5 to 5.0V)
Ceramic 4.7μF (Set output voltage in the range from 1.5 to 2.5V)
Input Capacitor ; Ceramic 2.2μF
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